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 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.