Intrauterine Devices
Conditions
Keywords
Contraception, Breast-feeding, Electronic medical records, Uterine perforation, Expulsion of intrauterine device
Brief summary
Study to analyze electronic medical records of women using an intrauterine device (IUD). The study was required by the FDA for the marketed IUD Mirena (US Post-marketing requirement; short name of study: APEX IUD). The study analyzed the risks that the IUD was expelled or perforated the womb for the following group comparisons: * Women who were breastfeeding at the time of IUD insertion and within 52 weeks postpartum versus women who were not breastfeeding at the time of IUD insertion and within 52 weeks postpartum. * Women who had a first observed IUD insertion within different time periods after childbirth (i.e., ≤ 6 weeks, \> 6 weeks and ≤ 14 weeks, \> 14 weeks and ≤ 52 weeks) versus women who had their first observed IUD insertion more than 52 weeks after childbirth, including women without a recorded delivery within the past 52 weeks. An additional analysis involved 5-level postpartum timing (i.e., 0 to 3 days, 4 days to ≤ 6 weeks, \> 6 weeks to ≤ 14 weeks, \> 14 weeks to ≤ 52 weeks) versus the \> 52 week postpartum group. The study also analyzed the risks that the IUD was expelled or perforated the womb for different types of IUDs. In addition, the study aimed to assess the following interactions: * The extent to which the type of IUD (IUDs releasing the hormone LNG versus Copper IUDs) modified the risk that an IUD was expelled or perforated the womb in relation to breastfeeding and/ or in relation to the point in time when the IUD was inserted after childbirth. * The extent to which the breastfeeding status modified the risk that an IUD was expelled or perforated the womb in relation to the point in time when the IUD was inserted after childbirth.
Interventions
DEVICEIntrauterine device
Intrauterine devices, e.g. BAY86-5028 (Mirena, Skyla, Kyleena), Liletta and ParaGard
Sponsors
Bayer
Study design
Observational model
COHORT
Time perspective
RETROSPECTIVE
Eligibility
Sex/Gender
FEMALE
Age
No minimum to 50 Years
Healthy volunteers
Yes
Inclusion criteria
* Women with evidence in the database of insertion of an IUD (e.g. levonorgestrel-releasing, copper) during the study time window for each site * Enrolled in the database with electronic medical records available for review for at least 12 months before the IUD insertion
Exclusion criteria
\- Women with more than 50 years of age at the time of the IUD-insertion
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Crude Incidence Rate of Uterine Perforation Stratified by Breastfeeding Status Among Women Within 52 Weeks Postpartum-first Observed IUD Insertions | Up to 11 years | Crude incidence rate was calculated as the number of outcomes occurring during the person-time at risk divided by the total person-time at risk (in person-years) |
| Cumulative Incidence of Uterine Perforation Stratified by Breastfeeding Status Among Women Within 52 Weeks Postpartum-first Observed IUD Insertions | At 1 year and 5 years of follow-up | Crude estimates of the cumulative incidence, defined as number of outcomes occurring up to a time point out of the number of IUD insertions |
| Adjusted Hazard Ratio (HR) for Breastfeeding Status and Uterine Perforation-first Observed IUD Insertions | Up to 11 years | Propensity score-adjusted hazard ratio to evaluate whether the risk of uterine perforation among women who were breastfeeding at the time of first observed IUD insertion differs from the risk of uterine perforation among women who were not breastfeeding at the time of first observed IUD insertion |
| Crude Incidence Rate of Uterine Perforation Categorized by Postpartum Timing-first Observed IUD Insertions | Up to 11 years | Crude incidence rate was calculated as the number of outcomes occurring during the person-time at risk divided by the total person-time at risk (in person-years) |
| Cumulative Incidence of Uterine Perforation Categorized by Postpartum Timing-first Observed IUD Insertions | At 1 year and 5 years of follow-up | Crude estimates of the cumulative incidence, defined as number of outcomes occurring up to a time point out of the number of IUD insertions |
| Adjusted Hazard Ratio (HR) for Postpartum Timing and Uterine Perforation-first Observed IUD Insertions | Up to 11 years | Adjusted for propensity scores and breastfeeding status, to evaluate whether the risk of uterine perforation among women who had a first observed IUD insertion within different time periods postpartum differs from the risk of uterine perforation among women who had their first observed IUD insertion more than 52 weeks postpartum, including women without a recorded delivery within the past 52 weeks. Reference group: IUD insertion \> 52 weeks postpartum |
| Adjusted Hazard Ratio (HR) for Postpartum Timing Risk 14-week Cut Point and Uterine Perforation-first Observed IUD Insertions | Up to 11 years | Adjusted for propensity scores and breastfeeding status, to estimate the risk of uterine perforation among women who had a first observed IUD insertion early in the postpartum period (i.e., up to 14 weeks postpartum) versus those who had a first observed IUD insertion late in the postpartum period (i.e., more than 14 weeks postpartum, including women without recorded delivery within the past 52 weeks). Reference group: IUD insertion \>14 weeks postpartum or with no recorded delivery |
| Adjusted Hazard Ratio (HR) for Postpartum Timing Risk 36-week Cut Point and Uterine Perforation-first Observed IUD Insertions | Up to 11 years | Adjusted for propensity scores and breastfeeding status, to estimate the risk of uterine perforation among women who had a first observed IUD insertion ≤ 36 weeks postpartum versus women who had a first observed IUD insertion \> 36 weeks postpartum, including women without recorded delivery within the past 52 weeks. Reference group: IUD insertion \>36 weeks postpartum or with no recorded delivery |
| Adjusted Incidence Rate Ratio (IRR) for Uterine Perforation-first Observed IUD Insertions | At 1 year and 5 years of follow-up | Adjusted for propensity score, overall and stratified by breastfeeding status at the time of IUD insertion for ≤ 36 weeks postpartum at IUD insertion versus \> 36 weeks postpartum or with no recorded delivery, at 1 year and 5 years of follow-up. Reference group: \> 36 weeks or no delivery |
| Adjusted Incidence Rate Difference (IRD) for Uterine Perforation-first Observed IUD Insertions | At 1 year and 5 years of follow-up | Propensity score-adjusted incidence rate differences (per 1,000 person-years) for uterine perforation for women ≤ 36 weeks postpartum at IUD insertion compared with those who were \> 36 weeks postpartum or with no recorded delivery, 1 year of follow-up and 5 years of follow-up, overall and stratified by breastfeeding status. Reference group: \> 36 weeks or no delivery |
| Crude Incidence Rate of Uterine Perforation Stratified by IUD Type-first Observed IUD Insertions | Up to 11 years | Crude incidence rate was calculated as the number of outcomes occurring during the person-time at risk divided by the total person-time at risk (in person-years) |
| Cumulative Incidence of Uterine Perforation Stratified by IUD Type-first Observed IUD Insertions | At 1 year and 5 years of follow-up | Crude estimates of the cumulative incidence, defined as number of outcomes occurring up to a time point out of the number of IUD insertions |
| Adjusted Hazard Ratio (HR) for IUD Type and Uterine Perforation-first Observed IUD Insertions | Up to 11 years | Propensity score-adjusted hazard ratio to evaluate whether the risk of uterine perforation among women with LNG-releasing IUD at the time of first observed IUD insertion differs from the risk of uterine perforation among women with copper IUD at the time of first observed IUD insertion |
| Crude Incidence Rate of Uterine Perforation Stratified by Menorrhagia Status-first Observed IUD Insertions | Up to 11 years | Crude incidence rate was calculated as the number of outcomes occurring during the person-time at risk divided by the total person-time at risk (in person-years) |
| Cumulative Incidence of Uterine Perforation Stratified by Menorrhagia Status-first Observed IUD Insertions | At 1 year and 5 years of follow-up | Crude estimates of the cumulative incidence, defined as number of outcomes occurring up to a time point out of the number of IUD insertions |
| Adjusted Hazard Ratio (HR) for Menorrhagia Status and Uterine Perforation-first Observed IUD Insertions | Up to 11 years | Propensity score-adjusted hazard ratio to evaluate whether the risk of uterine perforation among women using an IUD who have at least one diagnosis code indicating menorrhagia in the 12 months before IUD insertion differs from the risk of uterine perforation among women who do not have this indication |
| Effect Modification of Breastfeeding Status on Postpartum Timing for Uterine Perforation | Up to 11 years | Propensity score-adjusted hazard ratios to evaluate the extent to which breastfeeding status (yes vs. no) modified the association of uterine perforation for women with IUD insertion at different time periods postpartum (i.e., IUD insertion ≤ 14 weeks versus IUD insertion \> 14 weeks postpartum) among women with a recorded delivery within the past 52 weeks at the time of the first observed IUD insertion |
| Effect Modification of IUD Type on Breastfeeding Status for Uterine Perforation | Up to 11 years | Propensity score-adjusted hazard ratios to evaluate the extent to which type of IUD (LNG-IUD vs. copper IUD) modified the association between uterine perforation and breastfeeding among women who were and were not breastfeeding at the time of first observed IUD insertion |
| Effect Modification of IUD Type on Postpartum Timing for Uterine Perforation | Up to 11 years | Adjusted for propensity score and breastfeeding status, to evaluate the extent to which type of IUD (LNG-IUD vs. copper IUD) modified the association between uterine perforation and postpartum timing of IUD insertion for women with IUD insertion at different time periods postpartum (i.e., ≤ 6 weeks, \> 6 and ≤ 14 weeks, \> 14 and ≤ 52 weeks) versus IUD insertion more than 52 weeks postpartum, including no recorded delivery within the past 52 weeks, at the time of the first observed IUD insertion. Reference group: LNG-IUD or Copper IUD, \> 52 weeks or no delivery |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Crude Incidence Rate of IUD Expulsion Stratified by Breastfeeding Status Among Women Within 52 Weeks Postpartum-first Observed IUD Insertions | Up to 11 years | Crude incidence rate was calculated as the number of outcomes occurring during the person-time at risk divided by the total person-time at risk (in person-years) |
| Number of Indicators of a Potentially Difficult Insertion, Overall, by IUD Type and by Menorrhagia Status-first Observed IUD Insertions | Up to 11 years | To describe the prevalence of indicators of a difficult IUD insertion (e.g., need for cervical dilation, ultrasound guidance, paracervical block, clinician not indicating difficulty, use of misoprostol among all users) |
| Cumulative Incidence of IUD Expulsion Stratified by Breastfeeding Status Among Women Within 52 Weeks Postpartum-first Observed IUD Insertions | At 1 year and 5 years of follow-up | Crude estimates of the cumulative incidence, defined as number of outcomes occurring up to a time point out of the number of IUD insertions |
| Adjusted Hazard Ratio (HR) for Breastfeeding Status and IUD Expulsion-first Observed IUD Insertions | Up to 11 years | Propensity score-adjusted to evaluate whether the risk of IUD expulsion among women who were breastfeeding at the time of first observed IUD insertion differs from the risk of IUD expulsion among women who were not breastfeeding at the time of first observed IUD insertion |
| Crude Incidence Rate of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions | Up to 11 years | Crude incidence rate was calculated as the number of outcomes occurring during the person-time at risk divided by the total person-time at risk (in person-years) |
| Cumulative Incidence of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions | At 1 year and 5 years of follow-up | Crude estimates of the cumulative incidence, defined as number of outcomes occurring up to a time point out of the number of IUD insertions |
| Adjusted Hazard Ratio (HR) for Postpartum Timing and IUD Expulsion-first Observed IUD Insertions | Up to 11 years | Adjusted for propensity score and breastfeeding status, to evaluate whether the risk of IUD expulsion before and after 49 days of insertion among women who had a first observed IUD insertion within different time periods postpartum differs from the risk of IUD expulsion among women who had their first observed IUD insertion more than 52 weeks postpartum, including women without a recorded delivery within the past 52 weeks Reference group: IUD insertion \> 52 weeks postpartum |
| Adjusted Hazard Ratio (HR) for Postpartum Timing Risk 14-week Cut Point and IUD Expulsion-first Observed IUD Insertions | Up to 11 years | Adjusted for propensity scores, to estimate the risk of IUD expulsion among women who had a first observed IUD insertion early in the postpartum period (i.e., up to 14 weeks postpartum) versus those who had a first observed IUD insertion late in the postpartum period (i.e., more than 14 weeks postpartum, including women without recorded delivery within the past 52 weeks). Reference group: IUD insertion \>14 weeks postpartum or with no recorded delivery |
| Adjusted Hazard Ratio (HR) for Postpartum Timing Risk 36-week Cut Point and IUD Expulsion-first Observed IUD Insertions | Up to 11 years | Adjusted for propensity scores, to estimate the risk of IUD expulsion among women who had a first observed IUD insertion ≤ 36 weeks postpartum versus women who had a first observed IUD insertion \> 36 weeks postpartum, including women without recorded delivery within the past 52 weeks. Reference group: IUD insertion \>36 weeks postpartum or with no recorded delivery |
| Adjusted Incidence Rate Ratio (IRR) for IUD Expulsion-first Observed IUD Insertions | At 1 year and 5 years of follow-up | Overall and stratified by breastfeeding status at the time of IUD insertion for IUD expulsion for ≤ 36 weeks postpartum at IUD insertion versus \> 36 weeks postpartum or with no recorded delivery, at 1 year and 5 years of follow-up Reference group: \> 36 weeks or no delivery |
| Adjusted Incidence Rate Difference (IRD) for IUD Expulsion-first Observed IUD Insertions | At 1 year and 5 years of follow-up | Adjusted incidence rate differences (per 1,000 person-years) for IUD expulsion for women ≤ 36 weeks postpartum at IUD insertion compared with those who were \> 36 weeks postpartum or with no recorded delivery, 1 year of follow-up and 5 years of follow-up, overall and stratified by breastfeeding status Reference group: \> 36 weeks or no delivery |
| Crude Incidence Rate of IUD Expulsion Stratified by IUD Type-first Observed IUD Insertions | Up to 11 years | Crude incidence rate was calculated as the number of outcomes occurring during the person-time at risk divided by the total person-time at risk (in person-years) |
| Cumulative Incidence of IUD Expulsion Stratified by IUD Type-first Observed IUD Insertions | At 1 year and 5 years of follow-up | Crude estimates of the cumulative incidence, defined as number of outcomes occurring up to a time point out of the number of IUD insertions |
| Adjusted Hazard Ratio (HR) for IUD Type and IUD Expulsion-first Observed IUD Insertions | Up to 11 years | Propensity score adjusted to evaluate whether the risk of IUD expulsion among women with LNG-releasing IUD at the time of first observed IUD insertion differs from the risk of IUD expulsion among women with copper IUD at the time of first observed IUD insertion |
| Crude Incidence Rate of IUD Expulsion Stratified by Menorrhagia Status-first Observed IUD Insertions | Up to 11 years | Crude incidence rate was calculated as the number of outcomes occurring during the person-time at risk divided by the total person-time at risk (in person-years) |
| Cumulative Incidence of IUD Expulsion Stratified by Menorrhagia Status-first Observed IUD Insertions | At 1 year and 5 years of follow-up | Crude estimates of the cumulative incidence, defined as number of outcomes occurring up to a time point out of the number of IUD insertions |
| Adjusted Hazard Ratio (HR) for Menorrhagia Status and IUD Expulsion-first Observed IUD Insertions | Up to 11 years | Propensity score adjusted to evaluate whether the risk of IUD expulsion among women using an IUD who have at least one diagnosis code indicating menorrhagia in the 12 months before IUD insertion differs from the risk of IUD expulsion among women who do not have this indication |
| Effect Modification of IUD Type on Breastfeeding Status for IUD Expulsion | Up to 11 years | Propensity score-adjusted hazard ratios to evaluate the extent to which type of IUD (LNG-IUD vs. copper IUD) modified the association between IUD expulsion and breastfeeding among women who were and were not breastfeeding at the time of first observed IUD insertion |
| Effect Modification of IUD Type on Postpartum Timing for IUD Expulsion | Up to 11 years | Adjusted for propensity score and breastfeeding status, to evaluate the extent to which type of IUD (LNG-IUD vs. copper IUD) modified the association between IUD expulsion and postpartum timing of IUD insertion for women with IUD insertion at different time periods postpartum (i.e., ≤ 6 weeks, \> 6 and ≤ 14 weeks, \> 14 and ≤ 52 weeks) versus IUD insertion more than 52 weeks postpartum, including no recorded delivery within the past 52 weeks, at the time of the first observed IUD insertion. Reference group: LNG-IUD or Copper IUD, \> 52 weeks or no delivery |
| Number of Indicators of a Potentially Difficult Insertion, Overall, by Breastfeeding Status, and by Postpartum Timing of IUD Insertion-first Observed IUD Insertions | Up to 11 years | To describe the prevalence of indicators of a difficult IUD insertion (e.g., need for cervical dilation, ultrasound guidance, paracervical block, clinician not indicating difficulty, use of misoprostol among all users) |
Countries
United States
Participant flow
Recruitment details
This study was a retrospective cohort study, using the data from three health care systems: Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and one research institute with access to a health information exchange, Regenstrief Institute (RI)
Pre-assignment details
Between 01 January 2001 and 30 April 2018, 326658 participants were identified: 322898 participants with intrauterine device (IUD) type available and 94817 participants with breastfeeding status available (and IUD insertion within 12 months postpartum)
Participants by arm
| Arm | Count |
|---|---|
| Women With IUD Women with an intrauterine device (IUD) and electronic health records in the Kaiser Permanente Northern California (KPNC), Kaiser Permanente Southern California (KPSC), Kaiser Permanente Washington (KPWA) and the Regenstrief Institute (RI) databases. | 326,658 |
| Total | 326,658 |
Baseline characteristics
| Characteristic | Women With IUD |
|---|---|
| Age, Customized > 28 to ≤ 36 years | 107871 Participants |
| Age, Customized ≤ 28 years | 119469 Participants |
| Age, Customized > 36 to ≤ 50 years | 99318 Participants |
| Breastfeeding status No delivery in the past year | 228834 Participants |
| Breastfeeding status No (for those ≤ 52 weeks postpartum) | 30631 Participants |
| Breastfeeding status Undetermined (for those ≤ 52 weeks postpartum) | 3007 Participants |
| Breastfeeding status Yes (for those ≤ 52 weeks postpartum) | 64186 Participants |
| IUD type Copper IUD | 63664 Participants |
| IUD type Levonorgestrel (LNG)-IUD | 259234 Participants |
| IUD type Unknown | 3760 Participants |
| Menorrhagia ≤ 12 months before insertion | 32552 Participants |
| Menorrhagia > 12 months or no diagnosis | 294106 Participants |
| Postpartum time of IUD insertion 0 to 3 days | 2788 Participants |
| Postpartum time of IUD insertion > 14 to ≤ 52 weeks | 21717 Participants |
| Postpartum time of IUD insertion 4 days to ≤ 6 weeks | 17272 Participants |
| Postpartum time of IUD insertion > 52 weeks or no delivery | 228834 Participants |
| Postpartum time of IUD insertion > 6 to ≤ 14 weeks | 56047 Participants |
| Race/Ethnicity, Customized Asian/Pacific Islander | 38911 Participants |
| Race/Ethnicity, Customized Hispanic black | 696 Participants |
| Race/Ethnicity, Customized Hispanic other | 56180 Participants |
| Race/Ethnicity, Customized Hispanic white | 42501 Participants |
| Race/Ethnicity, Customized Non-Hispanic black | 28323 Participants |
| Race/Ethnicity, Customized Non-Hispanic white | 137102 Participants |
| Race/Ethnicity, Customized Other or multiple | 16357 Participants |
| Race/Ethnicity, Customized Unknown | 6588 Participants |
| Sex/Gender, Customized Female | 326658 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 0 |
| other Total, other adverse events | 0 / 0 |
| serious Total, serious adverse events | 0 / 0 |
Outcome results
Primary
Adjusted Hazard Ratio (HR) for Breastfeeding Status and Uterine Perforation-first Observed IUD Insertions
Propensity score-adjusted hazard ratio to evaluate whether the risk of uterine perforation among women who were breastfeeding at the time of first observed IUD insertion differs from the risk of uterine perforation among women who were not breastfeeding at the time of first observed IUD insertion
Time frame: Up to 11 years
Population: Women who had given birth in the previous 52 weeks and had breastfeeding status yes or no were included in this analysis
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Women With IUD | Adjusted Hazard Ratio (HR) for Breastfeeding Status and Uterine Perforation-first Observed IUD Insertions | 1.37 ajusted hazard ratio |
Primary
Adjusted Hazard Ratio (HR) for IUD Type and Uterine Perforation-first Observed IUD Insertions
Propensity score-adjusted hazard ratio to evaluate whether the risk of uterine perforation among women with LNG-releasing IUD at the time of first observed IUD insertion differs from the risk of uterine perforation among women with copper IUD at the time of first observed IUD insertion
Time frame: Up to 11 years
Population: Women with either LNG-IUD (levonorgestrel-releasing intrauterine system) or copper IUD insertions
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Women With IUD | Adjusted Hazard Ratio (HR) for IUD Type and Uterine Perforation-first Observed IUD Insertions | 1.49 adjusted hazard ratio |
Primary
Adjusted Hazard Ratio (HR) for Menorrhagia Status and Uterine Perforation-first Observed IUD Insertions
Propensity score-adjusted hazard ratio to evaluate whether the risk of uterine perforation among women using an IUD who have at least one diagnosis code indicating menorrhagia in the 12 months before IUD insertion differs from the risk of uterine perforation among women who do not have this indication
Time frame: Up to 11 years
Population: Women with menorrhagia (heavy menstrual bleeding) status (yes/no) in the 12 months before IUD insertion
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Women With IUD | Adjusted Hazard Ratio (HR) for Menorrhagia Status and Uterine Perforation-first Observed IUD Insertions | 1.38 adjusted hazard ratio |
Primary
Adjusted Hazard Ratio (HR) for Postpartum Timing and Uterine Perforation-first Observed IUD Insertions
Adjusted for propensity scores and breastfeeding status, to evaluate whether the risk of uterine perforation among women who had a first observed IUD insertion within different time periods postpartum differs from the risk of uterine perforation among women who had their first observed IUD insertion more than 52 weeks postpartum, including women without a recorded delivery within the past 52 weeks. Reference group: IUD insertion \> 52 weeks postpartum
Time frame: Up to 11 years
Population: Women with first observed IUD insertions at different postpartum timing or women without recorded delivery within the past 52 weeks
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Women With IUD | Adjusted Hazard Ratio (HR) for Postpartum Timing and Uterine Perforation-first Observed IUD Insertions | ≤ 6 weeks postpartum | 6.29 ajusted hazard ratio |
| Women With IUD | Adjusted Hazard Ratio (HR) for Postpartum Timing and Uterine Perforation-first Observed IUD Insertions | > 6 weeks and ≤ 14 weeks postpartum | 4.65 ajusted hazard ratio |
| Women With IUD | Adjusted Hazard Ratio (HR) for Postpartum Timing and Uterine Perforation-first Observed IUD Insertions | > 14 weeks and ≤ 52 weeks postpartum | 2.94 ajusted hazard ratio |
Primary
Adjusted Hazard Ratio (HR) for Postpartum Timing Risk 14-week Cut Point and Uterine Perforation-first Observed IUD Insertions
Adjusted for propensity scores and breastfeeding status, to estimate the risk of uterine perforation among women who had a first observed IUD insertion early in the postpartum period (i.e., up to 14 weeks postpartum) versus those who had a first observed IUD insertion late in the postpartum period (i.e., more than 14 weeks postpartum, including women without recorded delivery within the past 52 weeks). Reference group: IUD insertion \>14 weeks postpartum or with no recorded delivery
Time frame: Up to 11 years
Population: Women with first observed IUD insertions at different postpartum timing or women without recorded delivery within the past 52 weeks
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Women With IUD | Adjusted Hazard Ratio (HR) for Postpartum Timing Risk 14-week Cut Point and Uterine Perforation-first Observed IUD Insertions | 3.44 adjusted hazard ratio |
Primary
Adjusted Hazard Ratio (HR) for Postpartum Timing Risk 36-week Cut Point and Uterine Perforation-first Observed IUD Insertions
Adjusted for propensity scores and breastfeeding status, to estimate the risk of uterine perforation among women who had a first observed IUD insertion ≤ 36 weeks postpartum versus women who had a first observed IUD insertion \> 36 weeks postpartum, including women without recorded delivery within the past 52 weeks. Reference group: IUD insertion \>36 weeks postpartum or with no recorded delivery
Time frame: Up to 11 years
Population: Women with first observed IUD insertions at different postpartum timing or women without recorded delivery within the past 52 weeks
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Women With IUD | Adjusted Hazard Ratio (HR) for Postpartum Timing Risk 36-week Cut Point and Uterine Perforation-first Observed IUD Insertions | 4.36 adjusted hazard ratio |
Primary
Adjusted Incidence Rate Difference (IRD) for Uterine Perforation-first Observed IUD Insertions
Propensity score-adjusted incidence rate differences (per 1,000 person-years) for uterine perforation for women ≤ 36 weeks postpartum at IUD insertion compared with those who were \> 36 weeks postpartum or with no recorded delivery, 1 year of follow-up and 5 years of follow-up, overall and stratified by breastfeeding status. Reference group: \> 36 weeks or no delivery
Time frame: At 1 year and 5 years of follow-up
Population: Women with first observed IUD insertions at different postpartum timing or women without recorded delivery within the past 52 weeks
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Women With IUD | Adjusted Incidence Rate Difference (IRD) for Uterine Perforation-first Observed IUD Insertions | Not breastfeeding, 1 year of follow-up | 3.92 per 1000 person-years |
| Women With IUD | Adjusted Incidence Rate Difference (IRD) for Uterine Perforation-first Observed IUD Insertions | Breastfeeding, 5 years of follow-up | 1.38 per 1000 person-years |
| Women With IUD | Adjusted Incidence Rate Difference (IRD) for Uterine Perforation-first Observed IUD Insertions | Not breastfeeding, 5 years of follow-up | 2.33 per 1000 person-years |
| Women With IUD | Adjusted Incidence Rate Difference (IRD) for Uterine Perforation-first Observed IUD Insertions | Overall, 1 year of follow-up | 3.75 per 1000 person-years |
| Women With IUD | Adjusted Incidence Rate Difference (IRD) for Uterine Perforation-first Observed IUD Insertions | Overall, 5 years of follow-up | 2.28 per 1000 person-years |
| Women With IUD | Adjusted Incidence Rate Difference (IRD) for Uterine Perforation-first Observed IUD Insertions | Breastfeeding, 1 year of follow-up | 0.63 per 1000 person-years |
Primary
Adjusted Incidence Rate Ratio (IRR) for Uterine Perforation-first Observed IUD Insertions
Adjusted for propensity score, overall and stratified by breastfeeding status at the time of IUD insertion for ≤ 36 weeks postpartum at IUD insertion versus \> 36 weeks postpartum or with no recorded delivery, at 1 year and 5 years of follow-up. Reference group: \> 36 weeks or no delivery
Time frame: At 1 year and 5 years of follow-up
Population: Women with first observed IUD insertions at different postpartum timing or women without recorded delivery within the past 52 weeks
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Women With IUD | Adjusted Incidence Rate Ratio (IRR) for Uterine Perforation-first Observed IUD Insertions | Overall, 1 year of follow-up | 4.72 adjusted incidence rate ratio |
| Women With IUD | Adjusted Incidence Rate Ratio (IRR) for Uterine Perforation-first Observed IUD Insertions | Overall, 5 years of follow-up | 4.10 adjusted incidence rate ratio |
| Women With IUD | Adjusted Incidence Rate Ratio (IRR) for Uterine Perforation-first Observed IUD Insertions | Breastfeeding, 1 year of follow-up | 1.11 adjusted incidence rate ratio |
| Women With IUD | Adjusted Incidence Rate Ratio (IRR) for Uterine Perforation-first Observed IUD Insertions | Not breastfeeding, 1 year of follow-up | 6.61 adjusted incidence rate ratio |
| Women With IUD | Adjusted Incidence Rate Ratio (IRR) for Uterine Perforation-first Observed IUD Insertions | Breastfeeding, 5 years of follow-up | 1.47 adjusted incidence rate ratio |
| Women With IUD | Adjusted Incidence Rate Ratio (IRR) for Uterine Perforation-first Observed IUD Insertions | Not breastfeeding, 5 years of follow-up | 4.86 adjusted incidence rate ratio |
Primary
Crude Incidence Rate of Uterine Perforation Categorized by Postpartum Timing-first Observed IUD Insertions
Crude incidence rate was calculated as the number of outcomes occurring during the person-time at risk divided by the total person-time at risk (in person-years)
Time frame: Up to 11 years
Population: Women with first observed IUD insertions at different postpartum timing or women without recorded delivery within the past 52 weeks
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Women With IUD | Crude Incidence Rate of Uterine Perforation Categorized by Postpartum Timing-first Observed IUD Insertions | ≤ 6 weeks postpartum | 5.14 per 1000 person-years |
| Women With IUD | Crude Incidence Rate of Uterine Perforation Categorized by Postpartum Timing-first Observed IUD Insertions | > 6 weeks and ≤ 14 weeks postpartum | 3.77 per 1000 person-years |
| Women With IUD | Crude Incidence Rate of Uterine Perforation Categorized by Postpartum Timing-first Observed IUD Insertions | > 14 weeks and ≤ 52 weeks postpartum | 2.24 per 1000 person-years |
| Women With IUD | Crude Incidence Rate of Uterine Perforation Categorized by Postpartum Timing-first Observed IUD Insertions | > 52 weeks postpartum or no delivery | 0.68 per 1000 person-years |
Primary
Crude Incidence Rate of Uterine Perforation Stratified by Breastfeeding Status Among Women Within 52 Weeks Postpartum-first Observed IUD Insertions
Crude incidence rate was calculated as the number of outcomes occurring during the person-time at risk divided by the total person-time at risk (in person-years)
Time frame: Up to 11 years
Population: Women who were within 52 weeks postpartum and were or were not breastfeeding at the time of IUD insertion
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Women With IUD | Crude Incidence Rate of Uterine Perforation Stratified by Breastfeeding Status Among Women Within 52 Weeks Postpartum-first Observed IUD Insertions | Breastfeeding | 4.25 per 1000 person-years |
| Women With IUD | Crude Incidence Rate of Uterine Perforation Stratified by Breastfeeding Status Among Women Within 52 Weeks Postpartum-first Observed IUD Insertions | Not breastfeeding | 2.50 per 1000 person-years |
Primary
Crude Incidence Rate of Uterine Perforation Stratified by IUD Type-first Observed IUD Insertions
Crude incidence rate was calculated as the number of outcomes occurring during the person-time at risk divided by the total person-time at risk (in person-years)
Time frame: Up to 11 years
Population: Women with either LNG-IUD (levonorgestrel-releasing intrauterine system) or copper IUD insertions
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Women With IUD | Crude Incidence Rate of Uterine Perforation Stratified by IUD Type-first Observed IUD Insertions | LNG-IUD | 1.64 per 1000 person-years |
| Women With IUD | Crude Incidence Rate of Uterine Perforation Stratified by IUD Type-first Observed IUD Insertions | Copper IUD | 1.27 per 1000 person-years |
Primary
Crude Incidence Rate of Uterine Perforation Stratified by Menorrhagia Status-first Observed IUD Insertions
Crude incidence rate was calculated as the number of outcomes occurring during the person-time at risk divided by the total person-time at risk (in person-years)
Time frame: Up to 11 years
Population: Women with menorrhagia (heavy menstrual bleeding) status (yes/no) in the 12 months before IUD insertion
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Women With IUD | Crude Incidence Rate of Uterine Perforation Stratified by Menorrhagia Status-first Observed IUD Insertions | Yes | 1.00 per 1000 person-years |
| Women With IUD | Crude Incidence Rate of Uterine Perforation Stratified by Menorrhagia Status-first Observed IUD Insertions | No | 1.63 per 1000 person-years |
Primary
Cumulative Incidence of Uterine Perforation Categorized by Postpartum Timing-first Observed IUD Insertions
Crude estimates of the cumulative incidence, defined as number of outcomes occurring up to a time point out of the number of IUD insertions
Time frame: At 1 year and 5 years of follow-up
Population: Women with first observed IUD insertions at different postpartum timing or women without recorded delivery within the past 52 weeks
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Women With IUD | Cumulative Incidence of Uterine Perforation Categorized by Postpartum Timing-first Observed IUD Insertions | ≤ 6 weeks postpartum (pp), 1 year of follow-up | 0.70 number of outcomes/IUD insertions (%) |
| Women With IUD | Cumulative Incidence of Uterine Perforation Categorized by Postpartum Timing-first Observed IUD Insertions | > 6 weeks and ≤ 14 weeks pp, 1 year of follow-up | 0.54 number of outcomes/IUD insertions (%) |
| Women With IUD | Cumulative Incidence of Uterine Perforation Categorized by Postpartum Timing-first Observed IUD Insertions | > 14 weeks and ≤ 52 weeks pp, 1 year of follow-up | 0.33 number of outcomes/IUD insertions (%) |
| Women With IUD | Cumulative Incidence of Uterine Perforation Categorized by Postpartum Timing-first Observed IUD Insertions | > 52 weeks pp or no delivery, 1 year of follow-up | 0.07 number of outcomes/IUD insertions (%) |
| Women With IUD | Cumulative Incidence of Uterine Perforation Categorized by Postpartum Timing-first Observed IUD Insertions | ≤ 6 weeks pp, 5 years of follow-up | 1.89 number of outcomes/IUD insertions (%) |
| Women With IUD | Cumulative Incidence of Uterine Perforation Categorized by Postpartum Timing-first Observed IUD Insertions | > 6 weeks and ≤ 14 weeks pp, 5 years of follow-up | 1.42 number of outcomes/IUD insertions (%) |
| Women With IUD | Cumulative Incidence of Uterine Perforation Categorized by Postpartum Timing-first Observed IUD Insertions | > 14 weeks and ≤ 52 weeks pp, 5 years of follow-up | 0.74 number of outcomes/IUD insertions (%) |
| Women With IUD | Cumulative Incidence of Uterine Perforation Categorized by Postpartum Timing-first Observed IUD Insertions | > 52 weeks pp or no delivery, 5 years of follow-up | 0.29 number of outcomes/IUD insertions (%) |
Primary
Cumulative Incidence of Uterine Perforation Stratified by Breastfeeding Status Among Women Within 52 Weeks Postpartum-first Observed IUD Insertions
Crude estimates of the cumulative incidence, defined as number of outcomes occurring up to a time point out of the number of IUD insertions
Time frame: At 1 year and 5 years of follow-up
Population: Women who were within 52 weeks postpartum and were or were not breastfeeding at the time of IUD insertion
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Women With IUD | Cumulative Incidence of Uterine Perforation Stratified by Breastfeeding Status Among Women Within 52 Weeks Postpartum-first Observed IUD Insertions | Breastfeeding, 1 year of follow-up | 0.60 number of outcomes/IUD insertions (%) |
| Women With IUD | Cumulative Incidence of Uterine Perforation Stratified by Breastfeeding Status Among Women Within 52 Weeks Postpartum-first Observed IUD Insertions | Not breastfeeding, 1 year of follow-up | 0.35 number of outcomes/IUD insertions (%) |
| Women With IUD | Cumulative Incidence of Uterine Perforation Stratified by Breastfeeding Status Among Women Within 52 Weeks Postpartum-first Observed IUD Insertions | Breastfeeding, 5 years of follow-up | 1.61 number of outcomes/IUD insertions (%) |
| Women With IUD | Cumulative Incidence of Uterine Perforation Stratified by Breastfeeding Status Among Women Within 52 Weeks Postpartum-first Observed IUD Insertions | Not breastfeeding, 5 years of follow-up | 0.88 number of outcomes/IUD insertions (%) |
Primary
Cumulative Incidence of Uterine Perforation Stratified by IUD Type-first Observed IUD Insertions
Crude estimates of the cumulative incidence, defined as number of outcomes occurring up to a time point out of the number of IUD insertions
Time frame: At 1 year and 5 years of follow-up
Population: Women with either LNG-IUD (levonorgestrel-releasing intrauterine system) or copper IUD insertions
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Women With IUD | Cumulative Incidence of Uterine Perforation Stratified by IUD Type-first Observed IUD Insertions | LNG-IUD, 5 years of follow up | 0.63 number of outcomes/IUD insertions (%) |
| Women With IUD | Cumulative Incidence of Uterine Perforation Stratified by IUD Type-first Observed IUD Insertions | Copper IUD, 5 years of follow up | 0.55 number of outcomes/IUD insertions (%) |
| Women With IUD | Cumulative Incidence of Uterine Perforation Stratified by IUD Type-first Observed IUD Insertions | LNG-IUD, 1 year of follow up | 0.22 number of outcomes/IUD insertions (%) |
| Women With IUD | Cumulative Incidence of Uterine Perforation Stratified by IUD Type-first Observed IUD Insertions | Copper IUD, 1 year of follow up | 0.16 number of outcomes/IUD insertions (%) |
Primary
Cumulative Incidence of Uterine Perforation Stratified by Menorrhagia Status-first Observed IUD Insertions
Crude estimates of the cumulative incidence, defined as number of outcomes occurring up to a time point out of the number of IUD insertions
Time frame: At 1 year and 5 years of follow-up
Population: Women with menorrhagia (heavy menstrual bleeding) status (yes/no) in the 12 months before IUD insertion
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Women With IUD | Cumulative Incidence of Uterine Perforation Stratified by Menorrhagia Status-first Observed IUD Insertions | Yes, 1 year of follow-up | 0.10 number of outcomes/IUD insertions (%) |
| Women With IUD | Cumulative Incidence of Uterine Perforation Stratified by Menorrhagia Status-first Observed IUD Insertions | No, 1 year of follow-up | 0.22 number of outcomes/IUD insertions (%) |
| Women With IUD | Cumulative Incidence of Uterine Perforation Stratified by Menorrhagia Status-first Observed IUD Insertions | Yes, 5 years of follow-up | 0.41 number of outcomes/IUD insertions (%) |
| Women With IUD | Cumulative Incidence of Uterine Perforation Stratified by Menorrhagia Status-first Observed IUD Insertions | No, 5 years of follow-up | 0.63 number of outcomes/IUD insertions (%) |
Primary
Effect Modification of Breastfeeding Status on Postpartum Timing for Uterine Perforation
Propensity score-adjusted hazard ratios to evaluate the extent to which breastfeeding status (yes vs. no) modified the association of uterine perforation for women with IUD insertion at different time periods postpartum (i.e., IUD insertion ≤ 14 weeks versus IUD insertion \> 14 weeks postpartum) among women with a recorded delivery within the past 52 weeks at the time of the first observed IUD insertion
Time frame: Up to 11 years
Population: Women who had given birth in the previous 52 weeks and had breastfeeding status yes or no were included in this analysis
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Women With IUD | Effect Modification of Breastfeeding Status on Postpartum Timing for Uterine Perforation | Breastfeeding yes, ≤ 14 vs. > 14 to ≤ 52 weeks | 1.36 adjusted hazard ratio |
| Women With IUD | Effect Modification of Breastfeeding Status on Postpartum Timing for Uterine Perforation | Breastfeeding no, ≤ 14 vs. > 14 to ≤ 52 weeks | 2.56 adjusted hazard ratio |
| Women With IUD | Effect Modification of Breastfeeding Status on Postpartum Timing for Uterine Perforation | ≤ 14 weeks, breastfeeding yes vs.no | 1.28 adjusted hazard ratio |
| Women With IUD | Effect Modification of Breastfeeding Status on Postpartum Timing for Uterine Perforation | > 14 to ≤ 52 weeks, breastfeeding yes vs.no | 2.41 adjusted hazard ratio |
Primary
Effect Modification of IUD Type on Breastfeeding Status for Uterine Perforation
Propensity score-adjusted hazard ratios to evaluate the extent to which type of IUD (LNG-IUD vs. copper IUD) modified the association between uterine perforation and breastfeeding among women who were and were not breastfeeding at the time of first observed IUD insertion
Time frame: Up to 11 years
Population: Women who had given birth in the previous 52 weeks and had breastfeeding status yes or no were included in this analysis
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Women With IUD | Effect Modification of IUD Type on Breastfeeding Status for Uterine Perforation | LNG-IUD, breastfeeding yes vs.no | 1.33 adjusted hazard ratio |
| Women With IUD | Effect Modification of IUD Type on Breastfeeding Status for Uterine Perforation | Copper IUD, breastfeeding yes vs.no | 1.66 adjusted hazard ratio |
Primary
Effect Modification of IUD Type on Postpartum Timing for Uterine Perforation
Adjusted for propensity score and breastfeeding status, to evaluate the extent to which type of IUD (LNG-IUD vs. copper IUD) modified the association between uterine perforation and postpartum timing of IUD insertion for women with IUD insertion at different time periods postpartum (i.e., ≤ 6 weeks, \> 6 and ≤ 14 weeks, \> 14 and ≤ 52 weeks) versus IUD insertion more than 52 weeks postpartum, including no recorded delivery within the past 52 weeks, at the time of the first observed IUD insertion. Reference group: LNG-IUD or Copper IUD, \> 52 weeks or no delivery
Time frame: Up to 11 years
Population: Women with either LNG-IUD (levonorgestrel-releasing intrauterine system) or copper IUD insertions
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Women With IUD | Effect Modification of IUD Type on Postpartum Timing for Uterine Perforation | LNG-IUD, > 6 to ≤ 14 weeks | 5.11 adjusted hazard ratio |
| Women With IUD | Effect Modification of IUD Type on Postpartum Timing for Uterine Perforation | LNG-IUD, > 14 to ≤ 52 weeks | 3.13 adjusted hazard ratio |
| Women With IUD | Effect Modification of IUD Type on Postpartum Timing for Uterine Perforation | Copper IUD, ≤ 6 weeks | 4.30 adjusted hazard ratio |
| Women With IUD | Effect Modification of IUD Type on Postpartum Timing for Uterine Perforation | LNG-IUD, ≤ 6 weeks | 6.78 adjusted hazard ratio |
| Women With IUD | Effect Modification of IUD Type on Postpartum Timing for Uterine Perforation | Copper IUD, > 6 to ≤ 14 weeks | 2.61 adjusted hazard ratio |
| Women With IUD | Effect Modification of IUD Type on Postpartum Timing for Uterine Perforation | Copper IUD, > 14 to ≤ 52 weeks | 2.01 adjusted hazard ratio |
Secondary
Adjusted Hazard Ratio (HR) for Breastfeeding Status and IUD Expulsion-first Observed IUD Insertions
Propensity score-adjusted to evaluate whether the risk of IUD expulsion among women who were breastfeeding at the time of first observed IUD insertion differs from the risk of IUD expulsion among women who were not breastfeeding at the time of first observed IUD insertion
Time frame: Up to 11 years
Population: Women who had given birth in the previous 52 weeks and had breastfeeding status yes or no were included in this analysis
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Women With IUD | Adjusted Hazard Ratio (HR) for Breastfeeding Status and IUD Expulsion-first Observed IUD Insertions | 0.71 adjusted hazard ratio |
Secondary
Adjusted Hazard Ratio (HR) for IUD Type and IUD Expulsion-first Observed IUD Insertions
Propensity score adjusted to evaluate whether the risk of IUD expulsion among women with LNG-releasing IUD at the time of first observed IUD insertion differs from the risk of IUD expulsion among women with copper IUD at the time of first observed IUD insertion
Time frame: Up to 11 years
Population: Women with either LNG-IUD (levonorgestrel-releasing intrauterine system) or copper IUD insertions
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Women With IUD | Adjusted Hazard Ratio (HR) for IUD Type and IUD Expulsion-first Observed IUD Insertions | 0.69 adjusted hazard ratio |
Secondary
Adjusted Hazard Ratio (HR) for Menorrhagia Status and IUD Expulsion-first Observed IUD Insertions
Propensity score adjusted to evaluate whether the risk of IUD expulsion among women using an IUD who have at least one diagnosis code indicating menorrhagia in the 12 months before IUD insertion differs from the risk of IUD expulsion among women who do not have this indication
Time frame: Up to 11 years
Population: Women with menorrhagia (heavy menstrual bleeding) status (yes/no) available in the 12 months before IUD insertion
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Women With IUD | Adjusted Hazard Ratio (HR) for Menorrhagia Status and IUD Expulsion-first Observed IUD Insertions | 2.79 adjusted hazard ratio |
Secondary
Adjusted Hazard Ratio (HR) for Postpartum Timing and IUD Expulsion-first Observed IUD Insertions
Adjusted for propensity score and breastfeeding status, to evaluate whether the risk of IUD expulsion before and after 49 days of insertion among women who had a first observed IUD insertion within different time periods postpartum differs from the risk of IUD expulsion among women who had their first observed IUD insertion more than 52 weeks postpartum, including women without a recorded delivery within the past 52 weeks Reference group: IUD insertion \> 52 weeks postpartum
Time frame: Up to 11 years
Population: Women with first observed IUD insertions at different postpartum timing or women without recorded delivery within the past 52 weeks
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Women With IUD | Adjusted Hazard Ratio (HR) for Postpartum Timing and IUD Expulsion-first Observed IUD Insertions | After 49 days, > 14 weeks and ≤ 52 weeks pp | 1.39 adjusted hazard ratio |
| Women With IUD | Adjusted Hazard Ratio (HR) for Postpartum Timing and IUD Expulsion-first Observed IUD Insertions | Within 49 days, ≤ 6 weeks postpartum (pp) | 1.93 adjusted hazard ratio |
| Women With IUD | Adjusted Hazard Ratio (HR) for Postpartum Timing and IUD Expulsion-first Observed IUD Insertions | Within 49 days, > 6 weeks and ≤ 14 weeks pp | 0.88 adjusted hazard ratio |
| Women With IUD | Adjusted Hazard Ratio (HR) for Postpartum Timing and IUD Expulsion-first Observed IUD Insertions | Within 49 days, > 14 weeks and ≤ 52 weeks pp | 1.38 adjusted hazard ratio |
| Women With IUD | Adjusted Hazard Ratio (HR) for Postpartum Timing and IUD Expulsion-first Observed IUD Insertions | After 49 days, ≤ 6 weeks pp | 1.32 adjusted hazard ratio |
| Women With IUD | Adjusted Hazard Ratio (HR) for Postpartum Timing and IUD Expulsion-first Observed IUD Insertions | After 49 days, > 6 weeks and ≤ 14 weeks pp | 1.03 adjusted hazard ratio |
Secondary
Adjusted Hazard Ratio (HR) for Postpartum Timing Risk 14-week Cut Point and IUD Expulsion-first Observed IUD Insertions
Adjusted for propensity scores, to estimate the risk of IUD expulsion among women who had a first observed IUD insertion early in the postpartum period (i.e., up to 14 weeks postpartum) versus those who had a first observed IUD insertion late in the postpartum period (i.e., more than 14 weeks postpartum, including women without recorded delivery within the past 52 weeks). Reference group: IUD insertion \>14 weeks postpartum or with no recorded delivery
Time frame: Up to 11 years
Population: Women with first observed IUD insertions at different postpartum timing or women without recorded delivery within the past 52 weeks
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Women With IUD | Adjusted Hazard Ratio (HR) for Postpartum Timing Risk 14-week Cut Point and IUD Expulsion-first Observed IUD Insertions | 0.88 adjusted hazard ratio |
Secondary
Adjusted Hazard Ratio (HR) for Postpartum Timing Risk 36-week Cut Point and IUD Expulsion-first Observed IUD Insertions
Adjusted for propensity scores, to estimate the risk of IUD expulsion among women who had a first observed IUD insertion ≤ 36 weeks postpartum versus women who had a first observed IUD insertion \> 36 weeks postpartum, including women without recorded delivery within the past 52 weeks. Reference group: IUD insertion \>36 weeks postpartum or with no recorded delivery
Time frame: Up to 11 years
Population: Women with first observed IUD insertions at different postpartum timing or women without recorded delivery within the past 52 weeks
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| Women With IUD | Adjusted Hazard Ratio (HR) for Postpartum Timing Risk 36-week Cut Point and IUD Expulsion-first Observed IUD Insertions | 0.95 adjusted hazard ratio |
Secondary
Adjusted Incidence Rate Difference (IRD) for IUD Expulsion-first Observed IUD Insertions
Adjusted incidence rate differences (per 1,000 person-years) for IUD expulsion for women ≤ 36 weeks postpartum at IUD insertion compared with those who were \> 36 weeks postpartum or with no recorded delivery, 1 year of follow-up and 5 years of follow-up, overall and stratified by breastfeeding status Reference group: \> 36 weeks or no delivery
Time frame: At 1 year and 5 years of follow-up
Population: Women with first observed IUD insertions at different postpartum timing or women without recorded delivery within the past 52 weeks
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Women With IUD | Adjusted Incidence Rate Difference (IRD) for IUD Expulsion-first Observed IUD Insertions | Breastfeeding, 1 year of follow-up | -10.79 per 1000 person-years |
| Women With IUD | Adjusted Incidence Rate Difference (IRD) for IUD Expulsion-first Observed IUD Insertions | Breastfeeding, 5 years of follow-up | -2.62 per 1000 person-years |
| Women With IUD | Adjusted Incidence Rate Difference (IRD) for IUD Expulsion-first Observed IUD Insertions | Not breastfeeding, 1 year of follow-up | 5.11 per 1000 person-years |
| Women With IUD | Adjusted Incidence Rate Difference (IRD) for IUD Expulsion-first Observed IUD Insertions | Overall, 1 year of follow-up | 4.28 per 1000 person-years |
| Women With IUD | Adjusted Incidence Rate Difference (IRD) for IUD Expulsion-first Observed IUD Insertions | Overall, 5 years of follow-up | 2.37 per 1000 person-years |
| Women With IUD | Adjusted Incidence Rate Difference (IRD) for IUD Expulsion-first Observed IUD Insertions | Not breastfeeding, 5 years of follow-up | 2.65 per 1000 person-years |
Secondary
Adjusted Incidence Rate Ratio (IRR) for IUD Expulsion-first Observed IUD Insertions
Overall and stratified by breastfeeding status at the time of IUD insertion for IUD expulsion for ≤ 36 weeks postpartum at IUD insertion versus \> 36 weeks postpartum or with no recorded delivery, at 1 year and 5 years of follow-up Reference group: \> 36 weeks or no delivery
Time frame: At 1 year and 5 years of follow-up
Population: Women with first observed IUD insertions at different postpartum timing or women without recorded delivery within the past 52 weeks
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Women With IUD | Adjusted Incidence Rate Ratio (IRR) for IUD Expulsion-first Observed IUD Insertions | Overall, 1 year of follow-up | 1.21 adjusted incidence rate ratio |
| Women With IUD | Adjusted Incidence Rate Ratio (IRR) for IUD Expulsion-first Observed IUD Insertions | Overall, 5 years of follow-up | 1.20 adjusted incidence rate ratio |
| Women With IUD | Adjusted Incidence Rate Ratio (IRR) for IUD Expulsion-first Observed IUD Insertions | Breastfeeding, 1 year of follow-up | 0.60 adjusted incidence rate ratio |
| Women With IUD | Adjusted Incidence Rate Ratio (IRR) for IUD Expulsion-first Observed IUD Insertions | Not breastfeeding, 1 year of follow-up | 1.25 adjusted incidence rate ratio |
| Women With IUD | Adjusted Incidence Rate Ratio (IRR) for IUD Expulsion-first Observed IUD Insertions | Breastfeeding, 5 years of follow-up | 0.80 adjusted incidence rate ratio |
| Women With IUD | Adjusted Incidence Rate Ratio (IRR) for IUD Expulsion-first Observed IUD Insertions | Not breastfeeding, 5 years of follow-up | 1.23 adjusted incidence rate ratio |
Secondary
Crude Incidence Rate of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions
Crude incidence rate was calculated as the number of outcomes occurring during the person-time at risk divided by the total person-time at risk (in person-years)
Time frame: Up to 11 years
Population: Women with first observed IUD insertions at different postpartum timing or women without recorded delivery within the past 52 weeks
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Women With IUD | Crude Incidence Rate of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions | ≤ 3 days | 46.54 per 1000 person-years |
| Women With IUD | Crude Incidence Rate of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions | 4 days to ≤ 6 weeks | 10.88 per 1000 person-years |
| Women With IUD | Crude Incidence Rate of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions | ≤ 6 weeks postpartum | 15.33 per 1000 person-years |
| Women With IUD | Crude Incidence Rate of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions | > 6 weeks and ≤ 14 weeks postpartum | 9.29 per 1000 person-years |
| Women With IUD | Crude Incidence Rate of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions | > 14 weeks and ≤ 52 weeks postpartum | 14.36 per 1000 person-years |
| Women With IUD | Crude Incidence Rate of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions | > 52 weeks postpartum or no delivery | 14.93 per 1000 person-years |
Secondary
Crude Incidence Rate of IUD Expulsion Stratified by Breastfeeding Status Among Women Within 52 Weeks Postpartum-first Observed IUD Insertions
Crude incidence rate was calculated as the number of outcomes occurring during the person-time at risk divided by the total person-time at risk (in person-years)
Time frame: Up to 11 years
Population: Women who were within 52 weeks postpartum and were or were not breastfeeding at the time of IUD insertion
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Women With IUD | Crude Incidence Rate of IUD Expulsion Stratified by Breastfeeding Status Among Women Within 52 Weeks Postpartum-first Observed IUD Insertions | Not breastfeeding | 14.58 per 1000 person-years |
| Women With IUD | Crude Incidence Rate of IUD Expulsion Stratified by Breastfeeding Status Among Women Within 52 Weeks Postpartum-first Observed IUD Insertions | Breastfeeding | 10.23 per 1000 person-years |
Secondary
Crude Incidence Rate of IUD Expulsion Stratified by IUD Type-first Observed IUD Insertions
Crude incidence rate was calculated as the number of outcomes occurring during the person-time at risk divided by the total person-time at risk (in person-years)
Time frame: Up to 11 years
Population: Women with either LNG-IUD (levonorgestrel-releasing intrauterine system) or copper IUD insertions
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Women With IUD | Crude Incidence Rate of IUD Expulsion Stratified by IUD Type-first Observed IUD Insertions | LNG-IUD | 13.95 per 1000 person-years |
| Women With IUD | Crude Incidence Rate of IUD Expulsion Stratified by IUD Type-first Observed IUD Insertions | Copper IUD | 14.08 per 1000 person-years |
Secondary
Crude Incidence Rate of IUD Expulsion Stratified by Menorrhagia Status-first Observed IUD Insertions
Crude incidence rate was calculated as the number of outcomes occurring during the person-time at risk divided by the total person-time at risk (in person-years)
Time frame: Up to 11 years
Population: Women with menorrhagia (heavy menstrual bleeding) status (yes/no) available in the 12 months before IUD insertion
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Women With IUD | Crude Incidence Rate of IUD Expulsion Stratified by Menorrhagia Status-first Observed IUD Insertions | Yes | 39.56 per 1000 person-years |
| Women With IUD | Crude Incidence Rate of IUD Expulsion Stratified by Menorrhagia Status-first Observed IUD Insertions | No | 11.10 per 1000 person-years |
Secondary
Cumulative Incidence of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions
Crude estimates of the cumulative incidence, defined as number of outcomes occurring up to a time point out of the number of IUD insertions
Time frame: At 1 year and 5 years of follow-up
Population: Women with first observed IUD insertions at different postpartum timing or women without recorded delivery within the past 52 weeks
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Women With IUD | Cumulative Incidence of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions | 4 days to ≤ 6 weeks, 5 years of follow-up | 3.87 number of outcomes/IUD insertions (%) |
| Women With IUD | Cumulative Incidence of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions | ≤ 6 weeks postpartum (pp), 1 year of follow-up | 2.46 number of outcomes/IUD insertions (%) |
| Women With IUD | Cumulative Incidence of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions | > 6 weeks and ≤ 14 weeks pp, 1 year of follow-up | 1.40 number of outcomes/IUD insertions (%) |
| Women With IUD | Cumulative Incidence of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions | > 6 weeks and ≤ 14 weeks pp, 5 years of follow-up | 3.18 number of outcomes/IUD insertions (%) |
| Women With IUD | Cumulative Incidence of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions | > 14 weeks and ≤ 52 weeks pp, 5 years of follow-up | 4.55 number of outcomes/IUD insertions (%) |
| Women With IUD | Cumulative Incidence of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions | > 52 weeks pp or no delivery, 5 years of follow-up | 4.88 number of outcomes/IUD insertions (%) |
| Women With IUD | Cumulative Incidence of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions | ≤ 3 days, 1 year of follow-up | 7.84 number of outcomes/IUD insertions (%) |
| Women With IUD | Cumulative Incidence of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions | > 14 weeks and ≤ 52 weeks pp, 1 year of follow-up | 2.33 number of outcomes/IUD insertions (%) |
| Women With IUD | Cumulative Incidence of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions | > 52 weeks pp or no delivery, 1 year of follow-up | 2.49 number of outcomes/IUD insertions (%) |
| Women With IUD | Cumulative Incidence of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions | ≤ 3 days, 5 years of follow-up | 10.73 number of outcomes/IUD insertions (%) |
| Women With IUD | Cumulative Incidence of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions | 4 days to ≤ 6 weeks, 1 year of follow-up | 1.61 number of outcomes/IUD insertions (%) |
| Women With IUD | Cumulative Incidence of IUD Expulsion Categorized by Postpartum Timing-first Observed IUD Insertions | ≤ 6 weeks pp, 5 years of follow-up | 4.81 number of outcomes/IUD insertions (%) |
Secondary
Cumulative Incidence of IUD Expulsion Stratified by Breastfeeding Status Among Women Within 52 Weeks Postpartum-first Observed IUD Insertions
Crude estimates of the cumulative incidence, defined as number of outcomes occurring up to a time point out of the number of IUD insertions
Time frame: At 1 year and 5 years of follow-up
Population: Women who were within 52 weeks postpartum and were or were not breastfeeding at the time of IUD insertion
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Women With IUD | Cumulative Incidence of IUD Expulsion Stratified by Breastfeeding Status Among Women Within 52 Weeks Postpartum-first Observed IUD Insertions | Breastfeeding, 1 year of follow-up | 1.55 number of outcomes/IUD insertions (%) |
| Women With IUD | Cumulative Incidence of IUD Expulsion Stratified by Breastfeeding Status Among Women Within 52 Weeks Postpartum-first Observed IUD Insertions | Not breastfeeding, 1 year of follow-up | 2.45 number of outcomes/IUD insertions (%) |
| Women With IUD | Cumulative Incidence of IUD Expulsion Stratified by Breastfeeding Status Among Women Within 52 Weeks Postpartum-first Observed IUD Insertions | Breastfeeding, 5 years of follow-up | 3.49 number of outcomes/IUD insertions (%) |
| Women With IUD | Cumulative Incidence of IUD Expulsion Stratified by Breastfeeding Status Among Women Within 52 Weeks Postpartum-first Observed IUD Insertions | Not breastfeeding, 5 years of follow-up | 4.57 number of outcomes/IUD insertions (%) |
Secondary
Cumulative Incidence of IUD Expulsion Stratified by IUD Type-first Observed IUD Insertions
Crude estimates of the cumulative incidence, defined as number of outcomes occurring up to a time point out of the number of IUD insertions
Time frame: At 1 year and 5 years of follow-up
Population: Women with either LNG-IUD (levonorgestrel-releasing intrauterine system) or copper IUD insertions
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Women With IUD | Cumulative Incidence of IUD Expulsion Stratified by IUD Type-first Observed IUD Insertions | LNG-IUD, 1 year of follow up | 2.30 number of outcomes/IUD insertions (%) |
| Women With IUD | Cumulative Incidence of IUD Expulsion Stratified by IUD Type-first Observed IUD Insertions | Copper IUD, 1 year of follow up | 2.30 number of outcomes/IUD insertions (%) |
| Women With IUD | Cumulative Incidence of IUD Expulsion Stratified by IUD Type-first Observed IUD Insertions | LNG-IUD, 5 years of follow up | 4.52 number of outcomes/IUD insertions (%) |
| Women With IUD | Cumulative Incidence of IUD Expulsion Stratified by IUD Type-first Observed IUD Insertions | Copper IUD, 5 years of follow up | 4.82 number of outcomes/IUD insertions (%) |
Secondary
Cumulative Incidence of IUD Expulsion Stratified by Menorrhagia Status-first Observed IUD Insertions
Crude estimates of the cumulative incidence, defined as number of outcomes occurring up to a time point out of the number of IUD insertions
Time frame: At 1 year and 5 years of follow-up
Population: Women with menorrhagia (heavy menstrual bleeding) status (yes/no) available in the 12 months before IUD insertion
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Women With IUD | Cumulative Incidence of IUD Expulsion Stratified by Menorrhagia Status-first Observed IUD Insertions | Yes, 1 year of follow-up | 6.89 number of outcomes/IUD insertions (%) |
| Women With IUD | Cumulative Incidence of IUD Expulsion Stratified by Menorrhagia Status-first Observed IUD Insertions | No, 1 year of follow-up | 1.78 number of outcomes/IUD insertions (%) |
| Women With IUD | Cumulative Incidence of IUD Expulsion Stratified by Menorrhagia Status-first Observed IUD Insertions | Yes, 5 years of follow-up | 11.89 number of outcomes/IUD insertions (%) |
| Women With IUD | Cumulative Incidence of IUD Expulsion Stratified by Menorrhagia Status-first Observed IUD Insertions | No, 5 years of follow-up | 3.72 number of outcomes/IUD insertions (%) |
Secondary
Effect Modification of IUD Type on Breastfeeding Status for IUD Expulsion
Propensity score-adjusted hazard ratios to evaluate the extent to which type of IUD (LNG-IUD vs. copper IUD) modified the association between IUD expulsion and breastfeeding among women who were and were not breastfeeding at the time of first observed IUD insertion
Time frame: Up to 11 years
Population: Women who had given birth in the previous 52 weeks and had breastfeeding status yes or no were included in this analysis
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Women With IUD | Effect Modification of IUD Type on Breastfeeding Status for IUD Expulsion | LNG-IUD, breastfeeding yes vs.no | 0.72 adjusted hazard ratio |
| Women With IUD | Effect Modification of IUD Type on Breastfeeding Status for IUD Expulsion | Copper IUD, breastfeeding yes vs.no | 0.66 adjusted hazard ratio |
Secondary
Effect Modification of IUD Type on Postpartum Timing for IUD Expulsion
Adjusted for propensity score and breastfeeding status, to evaluate the extent to which type of IUD (LNG-IUD vs. copper IUD) modified the association between IUD expulsion and postpartum timing of IUD insertion for women with IUD insertion at different time periods postpartum (i.e., ≤ 6 weeks, \> 6 and ≤ 14 weeks, \> 14 and ≤ 52 weeks) versus IUD insertion more than 52 weeks postpartum, including no recorded delivery within the past 52 weeks, at the time of the first observed IUD insertion. Reference group: LNG-IUD or Copper IUD, \> 52 weeks or no delivery
Time frame: Up to 11 years
Population: Women with either LNG-IUD (levonorgestrel-releasing intrauterine system) or copper IUD insertions
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Women With IUD | Effect Modification of IUD Type on Postpartum Timing for IUD Expulsion | LNG-IUD, ≤ 6 weeks | 1.59 adjusted hazard ratio |
| Women With IUD | Effect Modification of IUD Type on Postpartum Timing for IUD Expulsion | LNG-IUD, > 6 to ≤ 14 weeks | 1.01 adjusted hazard ratio |
| Women With IUD | Effect Modification of IUD Type on Postpartum Timing for IUD Expulsion | LNG-IUD, > 14 to ≤ 52 weeks | 1.40 adjusted hazard ratio |
| Women With IUD | Effect Modification of IUD Type on Postpartum Timing for IUD Expulsion | Copper IUD, ≤ 6 weeks | 1.23 adjusted hazard ratio |
| Women With IUD | Effect Modification of IUD Type on Postpartum Timing for IUD Expulsion | Copper IUD, > 6 to ≤ 14 weeks | 0.96 adjusted hazard ratio |
| Women With IUD | Effect Modification of IUD Type on Postpartum Timing for IUD Expulsion | Copper IUD, > 14 to ≤ 52 weeks | 1.35 adjusted hazard ratio |
Secondary
Number of Indicators of a Potentially Difficult Insertion, Overall, by Breastfeeding Status, and by Postpartum Timing of IUD Insertion-first Observed IUD Insertions
To describe the prevalence of indicators of a difficult IUD insertion (e.g., need for cervical dilation, ultrasound guidance, paracervical block, clinician not indicating difficulty, use of misoprostol among all users)
Time frame: Up to 11 years
Population: Women with first observed IUD insertions
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Women With IUD | Number of Indicators of a Potentially Difficult Insertion, Overall, by Breastfeeding Status, and by Postpartum Timing of IUD Insertion-first Observed IUD Insertions | Not breastfeeding | 1077 indicators |
| Women With IUD | Number of Indicators of a Potentially Difficult Insertion, Overall, by Breastfeeding Status, and by Postpartum Timing of IUD Insertion-first Observed IUD Insertions | ≤ 6 weeks postpartum | 573 indicators |
| Women With IUD | Number of Indicators of a Potentially Difficult Insertion, Overall, by Breastfeeding Status, and by Postpartum Timing of IUD Insertion-first Observed IUD Insertions | > 6 weeks and ≤ 14 weeks postpartum | 1261 indicators |
| Women With IUD | Number of Indicators of a Potentially Difficult Insertion, Overall, by Breastfeeding Status, and by Postpartum Timing of IUD Insertion-first Observed IUD Insertions | > 14 weeks and ≤ 52 weeks postpartum | 1146 indicators |
| Women With IUD | Number of Indicators of a Potentially Difficult Insertion, Overall, by Breastfeeding Status, and by Postpartum Timing of IUD Insertion-first Observed IUD Insertions | > 52 weeks postpartum or no delivery | 26797 indicators |
| Women With IUD | Number of Indicators of a Potentially Difficult Insertion, Overall, by Breastfeeding Status, and by Postpartum Timing of IUD Insertion-first Observed IUD Insertions | Overall | 29777 indicators |
| Women With IUD | Number of Indicators of a Potentially Difficult Insertion, Overall, by Breastfeeding Status, and by Postpartum Timing of IUD Insertion-first Observed IUD Insertions | Breastfeeding | 1686 indicators |
Secondary
Number of Indicators of a Potentially Difficult Insertion, Overall, by IUD Type and by Menorrhagia Status-first Observed IUD Insertions
To describe the prevalence of indicators of a difficult IUD insertion (e.g., need for cervical dilation, ultrasound guidance, paracervical block, clinician not indicating difficulty, use of misoprostol among all users)
Time frame: Up to 11 years
Population: Women with first observed IUD insertions
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Women With IUD | Number of Indicators of a Potentially Difficult Insertion, Overall, by IUD Type and by Menorrhagia Status-first Observed IUD Insertions | Overall | 29777 indicators |
| Women With IUD | Number of Indicators of a Potentially Difficult Insertion, Overall, by IUD Type and by Menorrhagia Status-first Observed IUD Insertions | LNG-IUD | 24666 indicators |
| Women With IUD | Number of Indicators of a Potentially Difficult Insertion, Overall, by IUD Type and by Menorrhagia Status-first Observed IUD Insertions | Copper IUD | 4648 indicators |
| Women With IUD | Number of Indicators of a Potentially Difficult Insertion, Overall, by IUD Type and by Menorrhagia Status-first Observed IUD Insertions | With menorrhagia in the past year | 3754 indicators |
| Women With IUD | Number of Indicators of a Potentially Difficult Insertion, Overall, by IUD Type and by Menorrhagia Status-first Observed IUD Insertions | Without menorrhagia in the past year | 26023 indicators |