Induction of Labor in Morbidly Obese Patients

Induction of Labor in Morbidly Obese Patients: Comparison of 50 mcg and 25 mcg Misoprostol - A Randomized Control Trial

The goal of this randomized control trial is to compare different doses of Misoprostol (25 mcg vs 50 mcg) in induction of labor (IOL) in morbidly obese patients with BMI >40. It is known that morbid obesity is a risk factor for failed IOL and ultimately cesarean delivery (CD.) If the rates of vaginal delivery in this population can improve, then surgical morbidity can be reduced in these patients.

Study Overview

• Status: Recruiting
• Conditions: Pregnancy; Morbid Obesity
• Intervention / Treatment: Drug: Misoprostol

Detailed Description

The rate of IOL continues to increase, from about 10% in 1990 to 23% in 2018. Patients with BMI >40 are at increased risk for failed IOL and needing a CD. Studies show that morbidly obese patients require higher doses of pitocin and multiple agents to achieve vaginal delivery, but optimal dosing of misoprostol has not been studied as well. Increasing the rate of vaginal delivery in this population will help decrease risk of surgical morbidity.

The investigators plan to conduct a randomized controlled double blinded trial. Patients who are scheduled for induction of labor after 34 weeks gestation, have a BMI >40, and meet all study inclusion criteria will be approached by research personnel during their outpatient appointments. Participants will be randomized to either receive 25 mcg vaginal misoprostol every 4 hours or 50 mcg vaginal misoprostol every 4 hours.

• Study Type: Interventional
• Enrollment (Estimated): 162
• Phase: Early Phase 1

Contacts and Locations

• Study Contact: Name: Rosa Drummond, MD; Phone Number: 4103285965; Email: rosa.drummond@umm.edu
• Study Contact Backup: Name: Krista Mehlhaff, DO; Phone Number: 4103285965; Email: KMehlhaff@som.umaryland.edu

Study Locations

• United States
  • Maryland
    • Baltimore, Maryland, United States, 21201
      • Recruiting
      • University of Maryland Medical Center
      • Contact: Rosa Drummond, MD; Phone Number: 410-328-6436; Email: rosa.drummond@umm.edu
      • Principal Investigator: Krista Mehlhaff, DO

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Morbidly obese (BMI ≥ 40 kg/m2) at admission for induction of labor
• Speaks English or Spanish
• Gestational age between 34 weeks and 0 days and 42 weeks and 6 days
• Age 18 years old or older
• Viable, single, cephalic fetus
• Intent to proceed with cervical ripening - cervical exam: dilation < 5 cm
• Contractions < 5 per 10 minutes

Exclusion Criteria:

• History of cesarean delivery
• Contraindication to prostaglandin administration (significant myomectomy, prior cesarean delivery)
• Contraindication to vaginal delivery (placenta previa, vasa previa, HIV with high viral load)
• Contraindications to labor (cardiac, neurosurgical, need for cesarean)
• Age < 18yo
• Fetal growth restriction with abnormal umbilical artery Doppler indices
• Cervical dilation >5 cm
• Contractions >5 per 10 minutes
• Significant vaginal bleeding with concern for placental abruption
• Non-reassuring fetal status or fetal heart rate decelerations
• Fetal demise or major fetal anomaly
• Inability to give consent

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Control - 25 mcg vaginal misoprostol; Participants will receive 25 mcg vaginal misoprostol every 4 hours.	Drug: Misoprostol; Participants will receive with 25 mcg or 50 mcg vaginal misoprostol every 4 hours.
Experimental: Intervention - 50 mcg vaginal misoprostol; Participants will receive 50 mcg vaginal misoprostol every 4 hours.	Drug: Misoprostol; Participants will receive with 25 mcg or 50 mcg vaginal misoprostol every 4 hours.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Achievement of complete cervical dilation	Start of IOL until complete dilation

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time interval from start of induction of labor (IOL) to complete cervical dilation		Start of IOL until complete dilation
Achievement of 6 cm cervical dilation/active labor		Start of IOL until 6 cm dilation
Time interval from start of IOL to 6 cm cervical dilation/active labor		Start of IOL until 6 cm dilation
Time interval from start of IOL to vaginal delivery		Start of IOL until delivery
Time interval from start of IOL to delivery		Start of IOL until delivery
Incidence of vaginal deliveries		Start of IOL until delivery
Incidence of cesarean deliveries		Start of IOL until delivery
Indication for cesarean delivery	Maternal or Fetal	Start of IOL until delivery
Cervical exam at time of cesarean delivery		Start of IOL until delivery
Number of patients with tachysystole		Start of IOL until delivery
Number of patients with tachysystole with non reassuring fetal heart rate (NRFHT)		Start of IOL until delivery
Number of patients requiring terbutaline		Start of IOL until delivery
Number of patients with chorioamnionitis		Start of IOL until delivery
Number of patients with postpartum hemorrhage		Start of IOL until discharge, assessed up to 4 days
Composite maternal morbidity (need for transfusion, sepsis, ICU admission, death)		Start of IOL until postpartum day 4
Composite neonatal morbidity (NICU admission, Apgar score =<7 at 5 minutes, sepsis, cord gas arterial pH <7.10 and/or base deficit < -12, active cooling protocol, death)		Start of IOL until discharge or day of life 30

Collaborators and Investigators

• Sponsor: University of Maryland, Baltimore

Publications and helpful links

General Publications

• Grobman WA, Rice MM, Reddy UM, Tita ATN, Silver RM, Mallett G, Hill K, Thom EA, El-Sayed YY, Perez-Delboy A, Rouse DJ, Saade GR, Boggess KA, Chauhan SP, Iams JD, Chien EK, Casey BM, Gibbs RS, Srinivas SK, Swamy GK, Simhan HN, Macones GA; Eunice Kennedy Shriver National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network. Labor Induction versus Expectant Management in Low-Risk Nulliparous Women. N Engl J Med. 2018 Aug 9;379(6):513-523. doi: 10.1056/NEJMoa1800566.
• Pevzner L, Powers BL, Rayburn WF, Rumney P, Wing DA. Effects of maternal obesity on duration and outcomes of prostaglandin cervical ripening and labor induction. Obstet Gynecol. 2009 Dec;114(6):1315-1321. doi: 10.1097/AOG.0b013e3181bfb39f.
• Ellis JA, Brown CM, Barger B, Carlson NS. Influence of Maternal Obesity on Labor Induction: A Systematic Review and Meta-Analysis. J Midwifery Womens Health. 2019 Jan;64(1):55-67. doi: 10.1111/jmwh.12935. Epub 2019 Jan 16.
• Hoyert, Donna L. "Maternal Mortality Rates in the United States, 2021." Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 16 Mar. 2023, www.cdc.gov/nchs/data/hestat/maternal-mortality/2021/maternal-mortality-rates-2021.htm.
• MarchofDimes. "Total Cesarean Deliveries by Maternal Race/Ethnicity: United States, 2019-2021 Average." March of Dimes | PeriStats, www.marchofdimes.org/peristats/data?reg=99&top=8&stop=356&lev=1&slev=1&obj=1. Accessed 14 Nov. 2023.
• "Adult Obesity Facts." Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 17 May 2022, www.cdc.gov/obesity/data/adult.html.
• Beckwith L, Magner K, Kritzer S, Warshak CR. Prostaglandin versus mechanical dilation and the effect of maternal obesity on failure to achieve active labor: a cohort study. J Matern Fetal Neonatal Med. 2017 Jul;30(13):1621-1626. doi: 10.1080/14767058.2016.1220523. Epub 2016 Aug 25.
• O'Dwyer V, O'Kelly S, Monaghan B, Rowan A, Farah N, Turner MJ. Maternal obesity and induction of labor. Acta Obstet Gynecol Scand. 2013 Dec;92(12):1414-8. doi: 10.1111/aogs.12263.
• Drummond R, Patel M, Myers M, Ritter A, Hurvitz JA, Goetzinger KR, Crimmins SD. Class III obesity is an independent risk factor for unsuccessful induction of labor. AJOG Glob Rep. 2022 Sep 23;2(4):100109. doi: 10.1016/j.xagr.2022.100109. eCollection 2022 Nov.

Study record dates

Study Major Dates

• Study Start (Actual): July 15, 2024
• Primary Completion (Estimated): May 1, 2026
• Study Completion (Estimated): October 1, 2026

Study Registration Dates

• First Submitted: December 4, 2023
• First Submitted That Met QC Criteria: January 9, 2024
• First Posted (Actual): January 10, 2024

Study Record Updates

• Last Update Posted (Actual): July 3, 2025
• Last Update Submitted That Met QC Criteria: July 2, 2025
• Last Verified: July 1, 2025

More Information

Terms related to this study

• Keywords: misoprostol; morbid obesity; induction of labor
• Additional Relevant MeSH Terms: Nutrition Disorders; Overnutrition; Body Weight; Overweight; Obesity; Obesity, Morbid; Physiological Effects of Drugs; Gastrointestinal Agents; Abortifacient Agents, Nonsteroidal; Abortifacient Agents; Reproductive Control Agents; Oxytocics; Anti-Ulcer Agents; Misoprostol
• Other Study ID Numbers: HP-00108436

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: Yes