Preterm Birth
Conditions
Keywords
preterm, prematurity, home visitation, system of care
Brief summary
Women with a history of a prior preterm birth (PTB) have a high probability of a recurrent preterm birth. Some risk factors and health behaviors that contribute to PTB may be amenable to intervention. Home visitation is a promising method to deliver evidence based interventions. We evaluated a system of care designed to reduce preterm births and hospital length of stay in a sample of pregnant women with a history of a PTB. All participants (N = 211) received standard prenatal care. Intervention participants (N = 109) also received home visits by certified nurse-midwives guided by protocols for specific risk factors (e.g., depressive symptoms, abuse, smoking). Data was collected via multiple methods and sources including intervention fidelity assessments. Average age was 27.6 years. Racial breakdown mirrored local demographics. Most women had a partner, a high school education, and Medicaid. Enhanced prenatal care by nurse-midwife home visits may limit some risk factors and shorten intrapartum length of stay for women with a prior PTB. This study contributes to knowledge about evidence-based home visit interventions directed at risk factors associated with PTB.
Detailed description
Preterm births (PTBs) are the leading cause of death in infants under the age of one. Tennessee (TN) is one of the lowest ranking states in the US for rates of PTBs (46th) and infant mortality (48th). Costs for neonatal care increase exponentially with decreasing gestational age, and there are lifelong consequences for families and communities. Despite medications and improved diagnostic tools, a 27% increase in PTBs has occurred in the past 20 years. With a history of one PTB, the probability of another PTB is approximately 30%. The risk of having another PTB rises to almost 70% if the woman has a history of more than one PTB. Relationships between a variety of factors (e.g., African American race, smoking, short interval between pregnancies, socio-environmental stressors) likely contribute to TN's high rate of PTBs. Several interventions have been identified to reduce PTBs and improve maternal and infant health indicators but with varying success; administering intramuscular injections of progesterone between 16 and 36 weeks gestation, providing some prenatal care in the home of women with a high risk pregnancy, increasing the interval between pregnancies, and reducing social factors that negatively impact health, such as smoking, substance abuse and stress. The overall purpose of this study was to determine if a combined medical and biobehavioral intervention would prevent PTBs and reduce healthcare costs in a sample of women who have had a prior PTB. The medical intervention was conventional prenatal and postpartum clinic care. The biobehavioral intervention included certified nurse midwife home visitors who engaged women in an integrated System of Care (SOC) during their prenatal care. Care continued during the first 18 months of the infant's life by maternal-child nurse visitors. Home visits were in addition to regularly scheduled conventional prenatal and postpartum clinic care. Main study questions were: Is there a difference in: 1) the length of gestational age of infants of high-risk pregnant women who receive the medical intervention and high-risk pregnant women who receive the SOC? 2) in health care costs between women who receive the medical intervention and the SOC? 3) intervals between the current pregnancy and a subsequent pregnancy across groups? and 4) in length of gestational age of current infant with gestational age of index prior preterm birth?
Interventions
Women in this group received conventional prenatal care and postpartum clinic care.
Advanced practice nurses provide targeted behavioral interventions during home visits. These visits were in addition to regularly scheduled conventional prenatal and postpartum clinic care. Specific protocols guided nurse interventions related to tobacco use, substance use and misuse, stress management, dental health, maternal infections, perinatal depressive symptoms, family violence, reproductive life plans and continuity of care. Home visits were continued in the postpartum period (through 18 months post-delivery) with a continued focus on risk factors identified during the prenatal period and internatal health care.
Sponsors
Study design
Eligibility
Inclusion criteria
* Documented history of previous preterm delivery. Defined as delivery from 20 weeks to 36 weeks 6 days gestation. * Proven pregnancy * Reside in Davidson County, Tennessee (TN) or surrounding county in 90 mile driving radius. * Less than 24 weeks gestation at enrollment * Will receive prenatal care at a Vnderbilt University Medical Center (VUMC) clinic * Willing to accept nurse home visits and be randomly assigned to conventional care or care with home visits * Speaks and understands English * Between the ages of 18 and 40 years.
Exclusion criteria
* Known fetal anomaly that can not be managed conservatively or fetal demise * Maternal medical or obstetrical complications including: * Current or scheduled cervical cerclage * PROM in current pregnancy prior to enrollment * Participation in an antenatal study in which the clinical status or intervention may influence gestational age at delivery * Profound mental dysfunction or under guardianship
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Infant Gestational Age | Time of delivery | Infant gestational age was determined by the weeks and days gestation documented in the maternal delivery record. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Maternal Length of Stay at Delivery | Hospital discharge point following delivery | Number of maternal hospital days associated with delivery |
Countries
United States
Participant flow
Recruitment details
The sample consisted of pregnant women receiving prenatal care with a (physician or nurse-midwife) at a large regional medical center in the Southeastern U.S. from April, 2007 through January, 2010.
Participants by arm
| Arm | Count |
|---|---|
| Treatment Group Advanced practice nurses provide targeted behavioral interventions during home visits. These visits were in addition to regularly scheduled conventional prenatal and postpartum clinic visits. Specific protocols guided nurse interventions related to tobacco use, substance use and misuse, stress management, dental health, maternal infections, perinatal depressive symptoms, family violence, reproductive life plans and continuity of care. Home visits were continued in the postpartum period (18 months post-delivery) with a continued focus on risk factors identified during the prenatal period and internatal health care. | 109 |
| Control Group Women assigned to the control arm of the study received conventional prenatal and postpartum clinic care.
Conventional prenatal and postpartum clinic care: Women in this group received conventional prenatal care and postpartum clinic care. | 102 |
| Total | 211 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Overall Study | did not meet assignment criteria | 4 | 2 |
| Overall Study | disenrolled due to pregnancy loss | 3 | 5 |
| Overall Study | found not to meet eligibility criteria | 3 | 4 |
| Overall Study | Withdrawal by Subject | 3 | 1 |
Baseline characteristics
| Characteristic | Control Group | Total | Treatment Group |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical Between 18 and 65 years | 102 Participants | 211 Participants | 109 Participants |
| Age, Continuous | 27.8 years STANDARD_DEVIATION 5.2 | 27.6 years STANDARD_DEVIATION 5.3 | 27.4 years STANDARD_DEVIATION 5.5 |
| Gestational age at enrollment in weeks | 15.29 weeks STANDARD_DEVIATION 4.57 | 15.43 weeks STANDARD_DEVIATION 4.57 | 15.43 weeks STANDARD_DEVIATION 4.57 |
| Level of education in years | 13.4 years STANDARD_DEVIATION 2.6 | 13.3 years STANDARD_DEVIATION 2.6 | 13.2 years STANDARD_DEVIATION 2.5 |
| Marital Status Divorced or Separated | 8 participants | 12 participants | 4 participants |
| Marital Status Married or Partnered | 75 participants | 153 participants | 78 participants |
| Marital Status Never Married | 19 participants | 46 participants | 27 participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Black or African American | 34 Participants | 75 Participants | 41 Participants |
| Race (NIH/OMB) More than one race | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 1 Participants | 2 Participants | 1 Participants |
| Race (NIH/OMB) White | 67 Participants | 134 Participants | 67 Participants |
| Region of Enrollment United States | 102 participants | 211 participants | 109 participants |
| Sex: Female, Male Female | 102 Participants | 211 Participants | 109 Participants |
| Sex: Female, Male Male | 0 Participants | 0 Participants | 0 Participants |
| Type of insurance Medicaid | 62 participants | 126 participants | 64 participants |
| Type of insurance None/self pay | 3 participants | 3 participants | 0 participants |
| Type of insurance Private/Champus | 36 participants | 80 participants | 44 participants |
| Type of insurance Unknown or not reported | 1 participants | 2 participants | 1 participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 0 / 122 | 0 / 114 |
| serious Total, serious adverse events | 0 / 122 | 0 / 114 |
Outcome results
Infant Gestational Age
Infant gestational age was determined by the weeks and days gestation documented in the maternal delivery record.
Time frame: Time of delivery
Population: ITT analysis used with all participants that birth information could be obtained.
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Intervention Group | Infant Gestational Age | 38.14 weeks |
| Control Group | Infant Gestational Age | 38.14 weeks |
Maternal Length of Stay at Delivery
Number of maternal hospital days associated with delivery
Time frame: Hospital discharge point following delivery
Population: Of the 211 participants, data on length of stay at delivery were available for 194 women. The most common reason for the lack of this information was that the birth did not take place at the study's medical center.
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Intervention Group | Maternal Length of Stay at Delivery | 2 days |
| Control Group | Maternal Length of Stay at Delivery | 3 days |