Misoprostol for Induction of Labor in Obese Women: Comparison Between 25 and 50 mcg Oral Administration

NCT ID: NCT05857059

Last Updated: 2023-10-24

Basic Information

• Recruitment Status: UNKNOWN
• Clinical Phase: NA
• Total Enrollment: 228 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2019-10-15
• Study Completion Date: 2024-06-30

Brief Summary

In recent decades, obesity has become a prevalent issue in Portugal, with 38.6% and 13.8% of the population being overweight or obese, respectively. Obese pregnant women have a higher rate of obstetric complications, including hypertensive complications, gestational diabetes and fetal macrosomia, leading to increased induction of labor (IOL) and cesarean section (CS) rates. To determine the effect of increasing oral misoprostol dose on CS rate in obese pregnant women undergoing IOL, a randomized controlled trial with a sample size of 114 cases in each group was calculated to detect a 15% difference in CS rate. The primary objective is to determine the effect of increasing oral misoprostol dose, with secondary goals being to compare successful IOL rates and their relationship with oral misoprostol dose, as well as to evaluate tolerability and side effects in relation to different doses of oral misoprostol.

Detailed Description

The prevalence of obesity has increased dramatically in recent decades, with implications for women of reproductive age and changes in obstetric and perinatal outcomes. In Portugal, it is estimated that 38.6 per cent and 13.8 per cent of the population are overweight or obese, respectively. Compared with women of normal weight, obese pregnant women have a higher rate of obstetric complications. These include hypertensive complications, gestational diabetes and fetal macrosomia. These factors lead to an increased need for IOL before the end of the pregnancy and, consequently, to a reduced degree of cervical dilatation prior to IOL. In addition, the above-mentioned co-morbidities are associated with a higher rate of CS. For all these reasons, obese women have higher IOL and CS rates. The literature also confirms that the degree of obesity is directly related to IOL failure. In some studies, the rate of failed induction is 20.2% and 24.2% in women with obesity grades I and II, respectively. However, few studies have been conducted to determine which IOL agents most commonly induce vaginal labour in obese women, and no studies have defined the most appropriate dose for maternal BMI.

This study provides a breakthrough in understanding the mechanism of labour and response to misoprostol in obese women, as there is a lack of prospective human studies in this area.

Sample size calculation was based on CS rate in obese versus non-obese groups as the primary outcome. According to previous studies, a 22% CS rate in non-obese pregnant women undergoing IOL was calculated, with a between-groups difference of 15% on CS rates being considered clinically significant. Therefore, we set the power at 80%, the alpha error at 0.05 and the ratio of the two study groups at 1:1. Accordingly, 114 cases were needed in each group to detect 15% difference in CS rate.

Primary objective: To determine the effect of increasing oral misoprostol dose on CS rate in obese pregnant women undergoing IOL.

Secondary goals: Comparison of successful IOL rates and their relationship with oral misoprostol dose. Evaluation of tolerability and side effects in relation to different doses of oral misoprostol.

Conditions

Labor, Induced; Obesity; Pregnancy; Cesarean Section

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: SINGLE

Study Groups

Misoprostol 25 mcg

Participants received misoprostol 25 mcg every 2 hours until the active stage of labour was attained or failed induction was diagnosed

Group Type: ACTIVE_COMPARATOR

Misoprostol 25 mcg

Intervention Type: DRUG

Misoprostol 50 mcg every 2 hours

Misoprostol 50 mcg

Participants received misoprostol 25 mcg matching misoprostol 50 mcg every 2 hours until the active stage of labour was attained or failed induction was diagnosed

Group Type: EXPERIMENTAL

Misoprostol 50 mcg

Intervention Type: DRUG

Misoprostol 50 mcg every 2 hours

Interventions

Misoprostol 25 mcg

Misoprostol 50 mcg every 2 hours

Intervention Type: DRUG

Misoprostol 50 mcg

Misoprostol 50 mcg every 2 hours

Intervention Type: DRUG

Eligibility Criteria

Inclusion Criteria

• BMI ≥ 30 kg/m2 recorded based on maternal weight at preconception or in the first trimester
• Singleton live gestation with vertex presentation
• Pregnancies followed in our institution with sonographic confirmation of gestational age in the first trimester
• Obstetrical indication for labor induction
• Bishop score of <5 at the time of induction of labor

Exclusion Criteria

• Underweight and normal weight women (BMI <30 kg/m2)
• Known hypersensitivity to prostaglandins
• Preterm gestations (< 37 weeks)
• Multiple gestation
• Women who cannot give their informed consent
• Contraindications for vaginal delivery
• Previous c-section or uterine scar due to previous gynecological surgery
• Maternal or fetal pathology (for example: fetal indications: non-reassuring fetal status - intra-uterine growth restriction with abnormal umbilical doppler, abnormal fetal cardiac rhythm; stillbirth; or maternal/pregnancy related indications such as placenta previa)

• Minimum Eligible Age: 15 Years
• Maximum Eligible Age: 55 Years
• Eligible Sex: FEMALE
• Accepts Healthy Volunteers: Yes

Sponsors

Unidade Local de Saúde de Coimbra, EPE

OTHER

Sponsor Role: lead

Responsible Party

Iolanda Ferreira

Assistente Hospitalar

Responsibility Role: PRINCIPAL_INVESTIGATOR

Locations

Iolanda João Mora Cruz de Freitas Ferreira

Coimbra, , Portugal

Site Status: RECRUITING

Countries

Portugal

Central Contacts

Iolanda Ferreira

Role: CONTACT

10862@chuc.min-saude.pt

+351 239 403 060

Facility Contacts

Iolanda Ferreira

Role: primary

10862@chuc.min-saude.pt

Other Identifiers

CHUC-151-17

Identifier Type: -

Identifier Source: org_study_id