Labor Induction, Early Amniotomy
Conditions
Keywords
Foley balloon
Brief summary
Amniotomy is commonly done in the management of labor, though there is little research guiding the timing of amniotomy. Recent research largely suggests a benefit to earlier amniotomy, reporting shorter labor courses with no increase in the number of cesarean deliveries. This is some research, however, that reports an increase in cesarean deliveries with early amniotomy. Due to the small number of studies evaluating this topic, as well as the conflicting results, more research is needed. Additionally, the method of cervical ripening prior to amniotomy should be accounted for, as it may have an impact on the overall labor course. The purpose of this study is to evaluate the impact of early versus delayed amniotomy on time of delivery time from induction to the active phase of labor, as well on total time to delivery and maternal and neonatal outcomes in women undergoing cervical ripening with the Foley balloon.
Detailed description
This will be an unblinded randomized clinical trial. The investigators will recruit 174 pregnant women undergoing induction of labor. Recruitment will occur on the Labor and Delivery unit at the time of induction, after the decision has been made to place a Foley balloon for cervical ripening. Enrolled subjects will be randomized to early or delayed amniotomy. Subjects randomized to early amniotomy will undergo amniotomy within 2 hours of Foley balloon removal. Subjects randomized to delayed amniotomy will undergo amniotomy at least 4 hours after Foley balloon removal.
Interventions
PROCEDUREAmniotomy
Artificial rupture of amniotic membranes
DEVICEFoley balloon
The Foley balloon is inserted transcervically and inflated to a volume of 60 cc. It may be spontaneously expelled or manually removed if in place for 12 hours.
Sponsors
The University of Texas Medical Branch, Galveston
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
FEMALE
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Age 18 * Singleton pregnancy * Term gestation (37 weeks gestation) * Cephalic presentation * Undergoing labor induction with transcervical Foley balloon
Exclusion criteria
* Previous uterine surgery * Prelabor rupture of membranes * Severe pre-eclampsia, HELLP, or eclampsia * HIV, HCV, or HBV * Heart disease * Fever (≥38 0C) at admission * Category II or III fetal heart rate tracing prior to randomization * Polyhydramnios * Fetal growth restriction \<3% * EFW \> 4200 g * Fetal demise or major congenital anomaly * Prisoners
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Time to Active Phase of Labor | At delivery | Total time from initiation of labor induction to reaching 6 cm cervical dilation |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Vaginal Delivery Rate | At delivery | Rate of vaginal delivery within 24, 36, and 48 hours |
| Cesarean Section Rate | At delivery | Rate of cesarean section and indications |
| Time to Delivery | At delivery | Total time from initiation of labor induction to delivery |
| Umbilical Cord Prolapse | At delivery | Rates of umbilical cord prolapse |
| Neonatal Outcome Composite | From admission to discharge, up to 2 weeks | Neonatal outcome composite including NICU admission, respiratory support, hypoxic ischemic encephalopathy, seizures, sepsis, meconium aspiration syndrome, birth trauma, intracranial or subgaleal hemorrhage, hypotension requiring pressors, and perinatal death. |
| Maternal Infection Composite | From admission to discharge, up to 2 weeks | Includes isolated maternal fever, chorioamnionitis, endometritis, wound infection |
Countries
United States
Participant flow
Recruitment details
150 subjects were enrolled between October 2020 and March 2023.
Participants by arm
| Arm | Count |
|---|---|
| Early Amniotomy Subjects randomized to this arm will undergo amniotomy within 2 hours of removal of Foley balloon.
Amniotomy: Artificial rupture of amniotic membranes
Foley balloon: The Foley balloon is inserted transcervically and inflated to a volume of 60 cc. It may be spontaneously expelled or manually removed if in place for 12 hours. | 75 |
| Delayed Amniotomy Subjects randomized to this arm will undergo amniotomy at least 4 hours after removal of Foley balloon.
Amniotomy: Artificial rupture of amniotic membranes
Foley balloon: The Foley balloon is inserted transcervically and inflated to a volume of 60 cc. It may be spontaneously expelled or manually removed if in place for 12 hours. | 74 |
| Total | 149 |
Baseline characteristics
| Characteristic | Early Amniotomy | Delayed Amniotomy | Total |
|---|---|---|---|
| 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 | 75 Participants | 74 Participants | 149 Participants |
| Age, Continuous | 24 years | 24 years | 24 years |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 1 Participants | 1 Participants | 2 Participants |
| Race (NIH/OMB) Black or African American | 14 Participants | 11 Participants | 25 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 | 0 Participants | 1 Participants | 1 Participants |
| Race (NIH/OMB) White | 60 Participants | 61 Participants | 121 Participants |
| Sex: Female, Male Female | 75 Participants | 74 Participants | 149 Participants |
| Sex: Female, Male Male | 0 Participants | 0 Participants | 0 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 75 | 0 / 74 |
| other Total, other adverse events | 0 / 75 | 0 / 74 |
| serious Total, serious adverse events | 0 / 75 | 0 / 74 |
Outcome results
Primary
Time to Active Phase of Labor
Total time from initiation of labor induction to reaching 6 cm cervical dilation
Time frame: At delivery
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Early Amniotomy | Time to Active Phase of Labor | 885 minutes |
| Delayed Amniotomy | Time to Active Phase of Labor | 975 minutes |
Secondary
Cesarean Section Rate
Rate of cesarean section and indications
Time frame: At delivery
Secondary
Maternal Infection Composite
Includes isolated maternal fever, chorioamnionitis, endometritis, wound infection
Time frame: From admission to discharge, up to 2 weeks
Secondary
Neonatal Outcome Composite
Neonatal outcome composite including NICU admission, respiratory support, hypoxic ischemic encephalopathy, seizures, sepsis, meconium aspiration syndrome, birth trauma, intracranial or subgaleal hemorrhage, hypotension requiring pressors, and perinatal death.
Time frame: From admission to discharge, up to 2 weeks
Secondary
Time to Delivery
Total time from initiation of labor induction to delivery
Time frame: At delivery
Secondary
Umbilical Cord Prolapse
Rates of umbilical cord prolapse
Time frame: At delivery
Secondary
Vaginal Delivery Rate
Rate of vaginal delivery within 24, 36, and 48 hours
Time frame: At delivery