Comparative Study of the Effectiveness of Double Priming Agents in Cervical Ripening and Induction of Labor in Nulliparas.

BACKGROUND: Induction of labor is the stimulation of contractions before the spontaneous onset of labor with or without ruptured membranes. The labor induction in the presence of an unfavorable cervix is associated with an increased likelihood of prolonged labor and increased incidence of chorioamnionitis and caesarean section. Consequently, performing cervical ripening before conventional methods of induction has become standard practice. Combined techniques have been proposed to improve the success rate of labor induction and to enhance the progression of labor by leveraging the synergistic effects of both pharmacological and mechanical methods. In this comparative study, we examine the effectiveness of using a Foley catheter with misoprostol versus a Foley catheter with oxytocin infusion, specifically focusing on the induction-to-delivery interval in nulliparous women.

METHOD: Ours is a cross-sectional study conducted on pregnant patients booked for antenatal care at the obstetrics and gynecology (OBG) department of Amrita Institute of Medical Sciences, Kochi, Kerala, India, between November 2018 and August 2020. The study population comprised primigravidae who were admitted at term for induction of labor using double priming agents. A patient was then assigned to one of the two induction methods using dual priming agents practiced in our institution for the induction of labor in a primigravida with an unfavorable cervical score. A study proforma was designed to record all the observations pertaining to primary and secondary objectives of the study. The quantitative variables, such as induction-to-delivery time, were expressed as mean+/-standard deviation. The categorical variables were expressed as frequency and percentage. To test the statistical difference in the time from a Foley catheter placement to delivery between the two groups (Foley + oxytocin and Foley + misoprostol), an independent t-test will be applied. To test the statistical significance of the association between labor characteristics, the presence or absence of maternal morbidity, and neonatal outcomes between the two groups, the chi-square test was applied.

RESULTS: We compared two methods of induction of labor with dual priming agents in nulliparous women. Our study did not find any difference in the induction-to-delivery interval between the two methods. However, there was a marginal advantage of two hours in a Foley catheter with the concomitant oxytocin group (17.03 + 6.51 vs. 19.32 + 6.6 hours), the difference was not statistically significant (p=0.70). The normal vaginal delivery rate was better in the Foley catheter with the Pitocin group (100% vs. 80.6% of patients), and the difference was statistically significant (p=0.04). Caesarean section, maternal, and neonatal outcomes were comparable with both methods, with no distinct advantage or disadvantage of one over the other.

CONCLUSION: Over the past several decades, the rate of labor induction has risen significantly, a trend that is unlikely to reverse in light of increasing maternal morbidities. In response, novel strategies are needed to meet the growing demands on labor and delivery units. Combination methods offer a promising approach for expediting labor without adding risks for either the mother or newborn.