Cervical Ripening for Obese Women: A Randomized, Comparative Effectiveness Trial (CROWN)

The Efficacy of Transcervical Foley Balloon Plus Vaginal Misoprostol Versus Vaginal Misoprostol Alone For Cervical Ripening In Nulliparous Obese Women: A Randomized, Comparative Effectiveness Trial

Obese pregnant women (BMI ≥ 30 kg/m2) are more likely than their normal-weight counterparts to require induction of labor because of increased rates of obstetric complications including pregnancy related hypertensive disorders, diabetes, and prolonged gestations. Several studies have shown that obese women experience increased labor duration and oxytocin needs when compared to normal-weight women. This in turn results in increased rates for unplanned cesarean delivery (CD) as a result of failed induction of labor (IOL), arrest disorders and non-reassuring fetal heart rate tracing, that is dose-dependent with increasing class of obesity. The investigators hypothesize that obese pregnant women and unfavorable cervix (Bishop score ≤ 6), IOL ≥ 24 weeks gestation using the Foley balloon plus vaginal misoprostol will result in reduced cesarean delivery rates when compared to vaginal misoprostol alone.

Study Overview

• Status: Completed
• Conditions: Obesity; Labor Induction; Cesarean Delivery
• Intervention / Treatment: Device: Foley Balloon + Vaginal Misoprostol; Drug: Vaginal Misoprostol

Detailed Description

Nulliparous pregnant women at ≥ 32 weeks' gestation admitted to labor and delivery for IOL and who meet the inclusion and exclusion criteria will be approached by the research staff. Group 1 will be composed of women allocated to the Foley balloon plus misoprostol. These women will receive vaginal misoprostol per standard protocol at 25 micrograms every 4 hours. In addition, a 26 Fr-Foley balloon catheter will be inserted by routine clinical standards. The Foley will be inserted through the internal cervical os, filled with 60 mL of normal saline, and then pulled snugly against the internal os. The catheter of the Foley will be taped to the patient's inner thigh under gentle traction. If the Foley is unable to be placed, the patient will be reexamined in 1 hour and placement will be reattempted if Bishop's score is still 6 or less by the healthcare provider. When the Foley balloon had fallen out or had to be removed because 12 hours have passed since insertion as per protocol, further management of labor will be left at the discretion of the labor team.

Group 2 will be composed of women allocated to vaginal misoprostol-only. These women will receive 25 micrograms of misoprostol per vagina every 4 hours. Once the cervix becomes favorable (Bishop score > 6), misoprostol administration will be discontinued. Similarly, further management will be left at the discretion of the labor team.

In both groups, if IV oxytocin is indicated, it will be withheld until 4 hours after the last dose of misoprostol to prevent uterine hyperstimulation. Other aspects of labor management will be similar for both groups, including continuous electronic fetal monitoring with external Doppler device or fetal scalp electrode. Uterine contraction assessment will be performed with either an external tocodynamometer or an intrauterine pressure catheter.

• Study Type: Interventional
• Enrollment (Actual): 236
• Phase: Phase 4

Contacts and Locations

Study Locations

• United States
  • Texas
    • Houston, Texas, United States, 77030
      • The University of Texas Health Science Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: Female

Description

Inclusion Criteria

• Nulliparous women aged 18 or above
• BMI ≥ 30 at the time of labor induction
• Singleton gestation
• Cephalic presentation (includes successful external cephalic version)
• Intact fetal membranes
• Unfavorable cervix (Bishop score of ≤ 6)
• Gestational age ≥ 32 weeks

Exclusion Criteria

• Patient not candidate for IOL with misoprostol as deemed by the treating physician
• Multiple gestation
• Major fetal anomalies
• Fetal demise

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Combined approach: Foley Balloon + Vaginal Misoprostol; These women will receive vaginal misoprostol per standard protocol at 25 micrograms every 4 hours. In addition, a 26 Fr-Foley balloon catheter will be inserted by routine clinical standards. The Foley will be inserted through the internal cervical os, filled with 60 mL of normal saline, and then pulled snugly against the internal os. The catheter of the Foley will be taped to the patient's inner thigh under gentle traction. If the Foley is unable to be placed, the patient will be reexamined in 1 hour and placement will be reattempted if Bishop's score is still 6 or less by the healthcare provider. When the Foley balloon had fallen out or had to be removed because 12 hours have passed since insertion as per protocol, further management of labor will be left at the discretion of the labor team.	Device: Foley Balloon + Vaginal Misoprostol
Active Comparator: Single approach: Vaginal Misoprostol only; These women will receive 25 micrograms of misoprostol per vagina every 4 hours. Once the cervix becomes favorable (Bishop score > 6), misoprostol administration will be discontinued. Further management will be left at the discretion of the labor team.	Drug: Vaginal Misoprostol; Other Names: Cytotec

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Number of Participants With a Need for Cesarean Delivery	Induction to delivery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Indication for Cesarean Delivery	Categories of Indications for Cesarean Delivery: = Cephalopelvic disproportion; = Failed induction/Failure to progress; = Cord prolapse; = Non-reassuring fetal tracing; = Malpresentation; = Placental abruption; = Other	Induction to delivery
Induction-to-delivery Interval in Hours		Induction to delivery
Number of Participants With a Need for Oxytocin Augmentation		Induction to delivery
Number of Participants Exhibiting Tachysystole Resulting in Fetal Heart Rate Abnormalities	Uterine tachysystole is a condition of excessively frequent uterine contractions during pregnancy. Tachysystole is indicated ≥ 5 contractions in a 10 minute period averaged over a 30-minute window.	Induction to delivery
Number of Participants With Clinical Chorioamnionitis	Clinical chorioamnionitis is indicated by maternal fever ≥ 100.4 Fahrenheit, uterine fundal tenderness, maternal or fetal tachycardia (>100/min and >160/min, respectively), and purulent or foul amniotic fluid.	Induction to delivery
Number of Participants With a Need for Operative Vaginal Delivery		Induction to delivery
Composite Maternal Morbidity as Indicated by the Number of Participants With Measures of Maternal Morbidity	Measures of maternal morbidity assessed: Maternal ICU admission; Postpartum endometritis; Surgical-site infections prior to discharge; Venous thromboembolism; Need for transfusion; Maternal death	Induction to discharge (approximately 5 days)
Number of Newborns Admitted to the Neonatal Intensive Care Unit (NICU)		From delivery to neonatal discharge (approximately 2 to 7 days)
Number of Newborns With Transient Tachypnea (TTN)		From delivery to neonatal discharge (approximately 2 to 7 days)
Number of Newborns With Respiratory Distress Syndrome (RDS)		From delivery to neonatal discharge (approximately 2 to 7 days)
Number of Newborns With Meconium Aspiration Syndrome		From delivery to neonatal discharge (approximately 2 to 7 days)
Number of Newborns With Culture-proven Sepsis		From delivery to neonatal discharge (approximately 2 to 7 days)
Number of Newborns With Seizures		From delivery to neonatal discharge (approximately 2 to 7 days)
Composite Neonatal Morbidity as Indicated by the Number of Newborns With Measures of Neonatal Morbidity	Measures of neonatal morbidity assessed: Apgar score ≤ 7 at 5 mins; Umbilical cord potential of hydrogen (pH) < 7.1; Neonatal injury: brachial plexus injury, fracture; Perinatal death	From delivery to neonatal discharge (approximately 2 to 7 days)

Collaborators and Investigators

• Sponsor: The University of Texas Health Science Center, Houston

Publications and helpful links

General Publications

• Viteri OA, Tabsh KK, Alrais MA, Salazar XC, Lopez JM, Fok RY, Chauhan SP, Sibai BM. Transcervical Foley Balloon Plus Vaginal Misoprostol versus Vaginal Misoprostol Alone for Cervical Ripening in Nulliparous Obese Women: A Multicenter, Randomized, Comparative-Effectiveness Trial. Am J Perinatol. 2021 Aug;38(S 01):e123-e128. doi: 10.1055/s-0040-1708805. Epub 2020 Apr 16.

Study record dates

Study Major Dates

• Study Start: January 1, 2016
• Primary Completion (Actual): June 24, 2018
• Study Completion (Actual): June 24, 2018

Study Registration Dates

• First Submitted: December 15, 2015
• First Submitted That Met QC Criteria: December 21, 2015
• First Posted (Estimate): December 24, 2015

Study Record Updates

• Last Update Posted (Actual): August 26, 2019
• Last Update Submitted That Met QC Criteria: August 7, 2019
• Last Verified: August 1, 2019

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Gastrointestinal Agents; Reproductive Control Agents; Anti-Ulcer Agents; Abortifacient Agents, Nonsteroidal; Abortifacient Agents; Oxytocics; Misoprostol
• Other Study ID Numbers: HSC-MS-15-0895