Contraction frequency after administration of misoprostol in obese versus nonobese women

Efficacy and safety of oral and vaginal administration of misoprostol for induction of labor in high-risk obese pregnant women with hypertension or diabetes mellitus

OBJECTIVE

This study aims to compare the safety and efficacy of misoprostol administered orally and vaginally in obese pregnant women at term with either gestational hypertension or diabetes.

METHODS

A total of 264 pregnant women were enrolled and categorized into two groups based on their primary condition: hypertension (134 cases) or diabetes mellitus (130 cases) and were further divided into subgroups for misoprostol administration: orally (Oral group) or vaginally (Vaginal group). The primary outcomes measured were changes in the Bishop score following treatment, induction of labor (IOL) success rates, requirement for oxytocin augmentation, duration of labor, mode of delivery, and cesarean section rates.

RESULTS

Significant enhancements in Bishop scores, decreased cesarean section rates and increased success rates of IOL were noted in both administration groups. The incidence of vaginal delivery within 24 h was significantly higher in the Vaginal group compared to the Oral group. Adverse effects, including nausea, uterine overcontraction, hyperfrequency of uterine contraction and uterine hyperstimulation without fetal heart rate deceleration, were significantly more prevalent in the Vaginal group than in the Oral group.

CONCLUSION

Misoprostol administration, both orally and vaginally, proves effective for labor induction in obese pregnant women with hypertension or diabetes. However, the oral route presents a lower risk of adverse maternal and neonatal outcomes, suggesting its preference for safer labor induction in this demographic.

Optimal misoprostol dosing among patients with a body mass index greater than 30: a randomized controlled trial

BACKGROUND

Patients with obesity experience an increased duration of labor with an increased risk for perinatal morbidity. When compared with parturients without obesity, they also experience fewer uterine contractions after administration of misoprostol. It is unclear if the same dose of misoprostol should be used for induction of labor in patients with obesity compared to non-obese patients. Therefore, we sought to investigate if a higher dose of misoprostol for patients with obesity is more effective.

OBJECTIVE

This study aimed to determine if 50 μg compared with 25 μg of vaginal misoprostol reduced the time from induction start to delivery among patients with obesity.

STUDY DESIGN

We performed a double-blinded, pragmatic randomized controlled trial, between June 1, 2022, and July 17, 2023. Patients with a body mass index ≥30 kg/m2 who underwent labor induction at ≥ 36 weeks' gestation, had a singleton gestation, and a cervical dilation ≤3 cm at admission were included. Patients were excluded if they had a contraindication to vaginal delivery or misoprostol administration. Patients were randomized to 25 or 50 μg of vaginal misoprostol, stratified by parity, body mass index <40 kg/m2 or ≥40 kg/m2, and provider intent to use mechanical dilation at the onset of labor induction. Usual labor management was followed at the discretion of the provider. The primary outcome was time from induction to delivery. A priori, we estimated that 90 subjects per group (N=180) were needed for an 85% power to detect a 3-hour difference between groups with a type I error of 5%. Analysis was by intention-to-treat. A 2-sample t test was used for the primary outcome, Cohen's d was used as a measure of effect, and P values were reported.

RESULTS

Of the 180 patients randomized, 88 were assigned to the 25 μg group and 92 were assigned to the 50 μg group. Of those, 96.1% of patients received the designated intervention. The baseline characteristics were similar between groups. No difference was found in the primary outcome of time to delivery (21.6 hours vs 18.6 hours; d=.28; 95% confidence interval, -0.02 to 0.57). In a planned subgroup analysis, multiparous patients delivered faster in the 50 μg group (15.2 hours vs 12.0 hours; d=.51; 95% confidence interval, 0.04-0.97). The risk for tachysystole associated with fetal heart tracing changes was rare overall (2.2%) and not significantly different between groups. No differences in maternal or neonatal adverse effects were observed.

CONCLUSION

Patients with obesity who underwent cervical ripening with 50 μg of vaginal misoprostol experienced a similar time to delivery when compared with those who received 25 μg of misoprostol. However, multiparous patients had a significantly reduced time to delivery when 50 μg was used. A higher dose of misoprostol may be a promising intervention for reducing time in labor, which warrants further study.

Effect of Maternal Age and Body Mass Index on Induction of Labor Using Oral Misoprostol in Late-Term Pregnancies: A Retrospective Cross-Sectional Study

INTRODUCTION

Several studies have shown that late- and post-term pregnancies are associated with an increased risk of perinatal morbidity and mortality. In this case, induction of labor is the recommended approach. For full-term pregnancies, various methods exist to prepare the cervix and/or commence labor. Prostaglandins serve the dual purpose of cervical ripening and labor induction, blurring the distinction between the two processes. The aim of this research was to evaluate the effect of maternal age and body mass index (BMI) on oral misoprostol induction of labor for late-term pregnancies.

METHODS

This was a retrospective cross-sectional study (ClinicalTrial ID: NCT06184139), including only late-term pregnancies in healthy nulliparous women carrying a single cephalic fetus with normal birthweight who underwent induction of labor with oral misoprostol. We used the oral misoprostol regimen proposed by the World Health Organization (WHO) for induction of labor in term singleton pregnancies in women who have not had a previous cesarean delivery and a Bishop score <7. The regimen was oral misoprostol in aqueous solution at the low dose of 25 μg every 2 h until a Bishop score ≥7, labor, or for a maximum of 8 doses.

RESULTS

One hundred and four pregnant women underwent induction of labor with oral misoprostol for late-term pregnancy on the 290th day of gestation. Study population was divided in two groups based on age (<35 and ≥35 years) and obesity (BMI <30 and ≥30). No statistically significant differences were recorded between younger and older women. Obese women reported a longer time between the last dose of misoprostol and cervical dilation of 6 cm (p = 0.01), a longer time between the last dose of misoprostol and delivery (p = 0.04), and a higher rate of grade II vaginal lacerations (p = 0.02).

CONCLUSIONS

Maternal BMI is a factor negatively influencing the efficacy of oral misoprostol for induction of labor in late-term pregnancy.

Effect of obesity on the time to a successful medical abortion with misoprostol in first-trimester missed abortion

OBJECTIVE

To evaluate the efficacy of misoprostol used in first-trimester abortion in obese women and to determine whether obesity is associated with time to a successful medical abortion.

METHODS

The records of patients diagnosed with missed abortion at our clinic between 2018 and 2021 were retrospectively reviewed. All women aged 18 to 45 years who were diagnosed with missed abortion in the first trimester and treated with misoprostol were included in the study. The cases were divided into two groups: obese (body mass index [BMI] ≥ 30 kg/m2) and non-obese (BMI < 30 kg/m2). First, they were simultaneously administered 200 μg misoprostol orally and 400 μg vaginally. After the first misoprostol administration, the dose was repeated vaginally at 400 μg every three hours if necessary. The effect of obesity on the time taken to achieve a medical abortion was evaluated.

RESULTS

A successful medical abortion occurred in 45.2% of the women in the obese group and 69.0% of those in the non-obese group. The time to uterine evacuation was 8.24 ± 4.03 h in the obese group and 6.35 ± 3.54 h in the non-obese group. The relationship between obesity and time to a successful medical abortion was evaluated using the Kaplan-Meier curve, which showed a significant difference between the two groups (p = 0.028).

CONCLUSION

Our findings show that obesity affects time to a successful medical abortion. In addition, the rate of successful medical abortion after misoprostol administration was lower in the obese women.

Effect of maternal age and body mass index on induction of labor with oral misoprostol for premature rupture of membrane at term: A retrospective cross-sectional study

The aim of this study was to evaluate the effect of maternal age and body mass index (BMI) on induction of labor with oral misoprostol for premature rupture of membrane (PROM) at term. We have conducted retrospective cross-sectional study, including only term (37 weeks or more of gestation) PROM in healthy nulliparous women with a negative vaginal-rectal swab for group B streptococcus, a single cephalic fetus with normal birthweight, and uneventful pregnancy that were induced after 24 h from PROM. Ninety-one patients were included. According to the multivariate logistic regression, age and BMI odds ratio (OR) for induction success were 0.795 and 0.857, respectively. The study population was divided into two groups based on age (<35 and ≥35 years) and obesity (BMI <30 and ≥30). Older women reported a higher induction failure rate (p < 0.001); longer time to cervical dilation of 6 cm (p = 0.03) and delivery (p < 0.001). Obese women reported a higher induction failure rate (p = 0.01); number of misoprostol doses (p = 0.03), longer time of induction (p = 0.03) to cervical dilatation of 6 cm (p < 0.001), and delivery (p < 0.001); and higher cesarean section (p = 0.012) and episiotomy rate (p = 0.007). In conclusion, maternal age and BMI are two of the main factors that influence oral misoprostol efficacy and affect the failure of induction rate in term PROM.

Evidence-Based Approaches to Labor Induction

Importance

The induction rate continues to increase in the United States placing pressure on the health care system with increasing cost and time spent on labor and delivery. Most labor induction regimens have evaluated uncomplicated singleton-term gestations. Unfortunately, the optimal labor regimens of medically complicated pregnancies have not been well described.

Objective

The aim of this study was to review the current available evidence regarding the various labor induction regimens and understand the evidence that exists for induction regimens in complicated pregnancies.

Evidence Acquisition

Data were acquired by a literature search on PubMed, ClinicalTrials.gov, the Cochrane Review database, the most recent American College of Obstetricians and Gynecologists practice bulletin on labor induction, and a review of the most recent edition on widely used obstetric texts for key words related to labor induction.

Results

Many heterogeneous clinical trials exist examining various labor induction regimens such as prostaglandin only, oxytocin only, or a combination of mechanical dilation with prostaglandins or oxytocin. Several Cochrane systematic reviews have been performed, which suggest a combination of prostaglandins and mechanical dilation results in an improved time to delivery when compared with single-use methods. Evaluating pregnancies complicated by maternal or fetal conditions, there exist retrospective cohorts describing significantly different labor outcomes. Although a few of these populations have planned or active clinical trials, most do not have an optimal labor induction regimen described.

Conclusions and Relevance

Most induction trials are significantly heterogeneous and limited to uncomplicated pregnancies. A combination of prostaglandins and mechanical dilation may result in improved outcomes. Complicated pregnancies have significantly different labor outcomes; however, almost none have well-described labor induction regimens.

Induction of labour in pregnant individuals with obesity

People with obesity may require induction of labour (IoL) due to a higher incidence of pre-existing comorbidities and pregnancy complications, as well as to prevent post-term pregnancies and late-term stillbirths. IoL at 39-40 weeks is associated with fewer caesarean births and lower morbidity for the pregnant person and neonate when compared with expectant management. Ensuring the success and safety of IoL in people with obesity requires adherence to evidence-based protocols for the management of labour induction and augmentation. Cervical ripening as well as the latent and active phases of labour in people with obesity may be considerably prolonged, requiring higher cumulative doses of oxytocin. This should be guided by intrauterine pressure catheters and early provision of neuraxial analgesia, where possible. There is insufficient evidence to recommend one method of IoL over another. The need for higher doses of prostaglandins and concurrent agents for cervical ripening should be studied in prospective studies.

Women's body mass index and oral administration of Misoprostol for induction of labor - A retrospective cohort study

Pregnant women who are obese are at greater risk of pregnancy complications, including preeclampsia, gestational diabetes, and macrosomia, leading to an increased likelihood of induced labor. Little is known about pregnant women with obesity and the dose of Misoprostol needed for induction of labor (IOL). To investigate whether the cumulative dose of Misoprostol needed for induction of labor (IOL) is associated with women's body mass index (BMI), we conducted a retrospective study of the use of oral Misoprostol for IOL at the Department of Obstetrics and Gynecology, Aarhus University Hospital - a tertiary referral delivery unit with 4800 deliveries a year. Data on IOL among 1637 women with singleton pregnancies was collected in the period January 1st, 2014, to October 4th, 2017. Low-risk women were induced in an outpatient setting. Primary outcomes were Misoprostol dose, time between start of induction (first dose of Angusta®) and completed delivery, and mode of delivery. Secondary outcomes were neonatal data as Apgar score and pH of the umbilical artery. In this study, we found the total dose of Misoprostol needed for induction increased significantly with increasing BMI (p < 0.005). The time to delivery and the risk of Cesarean section increased with rising BMI class. However, 76% of inductions among the women with obesity ended in a vaginal delivery. For the neonatal outcomes, a total of 16 children had an Apgar score below 7 at five minutes and 14 had a pH less than 7.0; none of these results differed significantly between BMI classes. The perinatal and maternal mortality rate was 0%.