Mode of Delivery Outcomes Following Misoprostol Induction in Women with Pre-Labour Rupture of Membranes: A Single-Center Study

Pre-labour rupture of membranes (PROM) is defined as the spontaneous rupture of fetal membranes before the onset of regular uterine contractions and occurs in approximately 8–10% of term pregnancies worldwide. It represents a common obstetric condition with significant clinical implications for both the mother and the fetus. While PROM may precede spontaneous labour in a proportion of women, delayed onset of labour is frequently associated with increased risks, including ascending intrauterine infection, chorioamnionitis, postpartum endometritis, and neonatal sepsis. Additionally, PROM has been linked to prolonged labour, higher rates of operative vaginal delivery, and cesarean section, particularly when labour does not ensue spontaneously within an acceptable timeframe. Given these potential complications, PROM remains an important contributor to maternal and neonatal morbidity, especially in resource-limited healthcare settings where access to timely intervention and monitoring may be constrained.

Current obstetric guidelines generally recommend induction of labour in women with PROM at term to reduce the risk of infectious morbidity without increasing adverse neonatal outcomes. Timely induction aims to shorten the latency period between membrane rupture and delivery, thereby minimizing maternal and neonatal exposure to infection. However, the decision to induce labour must carefully balance the benefits of expediting delivery against the potential for increased uterine intervention, including cesarean section. Achieving an optimal mode of delivery—particularly a successful vaginal birth—remains a key clinical objective, as operative delivery is associated with higher maternal morbidity, longer hospital stays, and increased healthcare costs. Consequently, identifying effective induction strategies that promote vaginal delivery while maintaining maternal and fetal safety is of substantial clinical importance.

Misoprostol, a synthetic prostaglandin E1 analogue, has gained widespread use as an agent for cervical ripening and induction of labour. It exerts its effect by promoting cervical softening and stimulating uterine contractions through prostaglandin receptor activation. Misoprostol offers several advantages over conventional induction agents, including low cost, wide availability, long shelf life, and ease of administration via oral or vaginal routes. These characteristics make it particularly attractive in low- and middle-income countries where healthcare resources are limited. Nevertheless, concerns persist regarding its safety profile, especially in the context of PROM, as misoprostol use has been associated with uterine tachysystole, hyperstimulation, and fetal heart rate abnormalities in some studies. Compared with oxytocin and prostaglandin E2 preparations, misoprostol has demonstrated comparable or superior efficacy in achieving vaginal delivery, although reported outcomes vary depending on dosing regimens, route of administration, and patient selection. As a result, its role in PROM continues to be actively evaluated.

Existing literature has reported mixed findings regarding mode of delivery outcomes following misoprostol induction in women with PROM. Several randomized trials and observational studies have demonstrated favorable vaginal delivery rates with misoprostol, while others have reported increased cesarean section rates or higher incidences of uterine hyperstimulation. Variability in study design, sample size, gestational age at induction, parity, and institutional protocols has contributed to inconsistent results. Importantly, much of the available evidence originates from high-income settings, with relatively limited data from low- and middle-income countries where clinical practices, patient demographics, and resource availability differ substantially. Furthermore, single-center, real-world studies reflecting routine obstetric practice remain underrepresented in the literature, despite their value in informing context-specific clinical decision-making.

In this context, the present single-center study was undertaken to contribute local evidence on delivery outcomes following misoprostol induction in women with PROM. Generating institution-specific data is particularly relevant for optimizing induction protocols, guiding clinical practice, and supporting evidence-based decision-making in comparable healthcare settings. Therefore, the objective of this study was to evaluate the mode of delivery outcomes following induction of labour with misoprostol among women presenting with pre-labour rupture of membranes at a tertiary care center.

A total of 150 women with pre-labour rupture of membranes who underwent induction of labour with misoprostol were included in the final analysis. The mean maternal age was 29.99 ± 6.65 years (range: 18–40 years). The mean gestational age at induction was 38.92 ± 1.09 weeks, while the mean duration of rupture of membranes prior to induction was 24.76 ± 13.77 hours. The mean induction-to-delivery interval was 15.09 ± 5.60 hours, the mean neonatal birth weight was 3.15 ± 0.43 kg, and the mean length of hospital stay was 2.47 ± 1.16 days. Baseline maternal and obstetric characteristics are summarized in Table 1..

Table 1. Baseline maternal and obstetric characteristics (n = 150)

Regarding the mode of delivery, spontaneous vaginal delivery was achieved in 95 (63.3%) women, 49 (32.7%) required cesarean section, and 6 (4.0%) underwent instrumental vaginal delivery. Uterine hyperstimulation was observed in 31 (20.7%) cases. Neonatal intensive care unit (NICU) admission was required for 51 (34.0%) neonates. With respect to maternal outcomes, 86 (57.3%) women had no postpartum complications, while 37  developed postpartum hemorrhage and 27 (18.0%) experienced postpartum fever. These delivery outcomes and complications are detailed in Table 2.

Table 2. Delivery outcomes and maternal–neonatal complications

Table 2. Delivery outcomes and maternal–neonatal complications

When stratified by maternal age group, spontaneous vaginal delivery remained the most frequent mode of delivery across all age categories. No statistically significant association was observed between maternal age group and mode of delivery (χ² = 4.69, p = 0.321). The age-stratified distribution of delivery outcomes is presented in Table 3.

Table 3. Association between maternal age group and mode of delivery

Stratification by gestational age group demonstrated that spontaneous vaginal delivery was more frequent among women induced at earlier gestational ages, whereas the proportion of cesarean sections increased with advancing gestational age. Detailed findings are shown in Table 4.

Table 4. Mode of delivery according to gestational age group

Analysis of NICU admission by mode of delivery showed no statistically significant association (χ² = 1.10, p = 0.578). NICU admissions occurred across all delivery modes, as summarized in Table 5.

Table 5. Association between mode of delivery and NICU admission

This single-center observational study evaluated mode of delivery outcomes following induction of labour with misoprostol in women presenting with pre-labour rupture of membranes (PROM). The principal findings demonstrate that spontaneous vaginal delivery was the predominant outcome, achieved in approximately two-thirds of women, while nearly one-third required cesarean section and only a small proportion underwent instrumental delivery. Maternal complications, including uterine hyperstimulation, postpartum hemorrhage, and postpartum fever, were observed but remained within clinically acceptable limits. Neonatal outcomes, particularly NICU admissions, were noted across all delivery modes, with no statistically significant association between mode of delivery and NICU admission. Collectively, these findings support the effectiveness and relative safety of misoprostol for labour induction in PROM within a real-world tertiary care setting.

The predominance of spontaneous vaginal delivery observed in this study is consistent with contemporary literature evaluating misoprostol use in PROM. Recent randomized trials and systematic reviews have reported vaginal delivery rates ranging from 55% to 75% following misoprostol induction, depending on dose, route of administration, and population characteristics [1–3]. These findings reinforce the role of misoprostol as an effective cervical ripening and labour-inducing agent in PROM, particularly when low-dose regimens are employed. The cesarean section rate observed in our cohort is comparable to rates reported in recent regional and international studies, where cesarean delivery following misoprostol induction ranged between 25% and 35% [2,4,5]. Variations in cesarean section rates across studies may reflect differences in obstetric practice patterns, parity distribution, Bishop score at induction, and institutional thresholds for operative intervention.

The induction-to-delivery interval observed in this study aligns with evidence suggesting that misoprostol facilitates timely labour progression in PROM. Several recent studies have demonstrated that misoprostol induction is associated with comparable or shorter induction-to-delivery intervals than oxytocin or prostaglandin E2 preparations, without compromising maternal or neonatal safety [3,6]. Shortening the latency period between membrane rupture and delivery is clinically relevant, as prolonged intervals have been associated with increased risks of maternal and neonatal infection [7]. The observed delivery intervals in our study support the clinical utility of misoprostol in achieving timely delivery while maintaining acceptable safety outcomes.

Maternal complications associated with misoprostol induction warrant careful interpretation. Uterine hyperstimulation was observed in a subset of women, a known pharmacological effect of prostaglandin agents. Recent literature indicates that the risk of uterine tachysystole is dose-dependent and is significantly reduced with low-dose (25 µg) vaginal misoprostol regimens, particularly when adequate monitoring is ensured [1,8]. The rates of postpartum hemorrhage and postpartum fever in our cohort are comparable to those reported in recent induction studies and do not appear to exceed expected baseline risks in PROM populations [4,9]. Differences in reported complication rates across studies may be attributable to variations in dosing protocols, labour monitoring practices, parity, and baseline obstetric risk profiles.

Neonatal outcomes are a critical consideration when evaluating induction agents in PROM. In the present study, NICU admission was required for approximately one-third of neonates, with no statistically significant association between NICU admission and mode of delivery. This finding is consistent with recent evidence indicating that misoprostol induction does not significantly increase adverse neonatal outcomes, including NICU admission, when compared with other induction methods [2,6,10]. Importantly, NICU admissions in PROM are often multifactorial and may reflect underlying neonatal conditions, intrapartum factors, or institutional admission policies rather than the induction agent itself. The absence of a significant association between delivery mode and NICU admission in our study supports the neonatal safety profile of misoprostol when used appropriately.

Analysis of maternal age revealed no significant association with mode of delivery, a finding that aligns with contemporary obstetric literature suggesting that maternal age alone is not a strong independent predictor of operative delivery in the absence of other risk factors [5,11]. In contrast, stratification by gestational age demonstrated a trend toward higher cesarean section rates with advancing gestational age. This observation is supported by recent studies reporting reduced induction success and increased operative delivery rates at later gestational ages, potentially due to reduced cervical favorability or altered myometrial responsiveness [6,12]. Although not all studies demonstrate statistically significant differences, this trend underscores the importance of individualized induction planning based on gestational age and cervical assessment.

From a clinical and public health perspective, the findings of this study have important implications. Misoprostol’s low cost, ease of storage, and multiple routes of administration make it particularly suitable for use in resource-limited and high-volume tertiary care settings. Current international guidelines recognize misoprostol as an acceptable agent for induction of labour in PROM when administered using evidence-based protocols and appropriate monitoring [13–15]. Our findings support these recommendations and provide locally generated evidence reinforcing the role of misoprostol as a practical and effective induction agent in similar healthcare contexts. The strengths of this study include its real-world design, standardized induction protocol, and comprehensive assessment of maternal and neonatal outcomes. However, several limitations should be acknowledged. The single-center design may limit generalizability to other settings with different patient populations or clinical practices. The absence of a comparator group using alternative induction agents precludes direct comparison of efficacy and safety. Additionally, long-term neonatal outcomes beyond NICU admission were not evaluated, limiting the assessment of extended neonatal safety. Future research should focus on multicenter studies to enhance external validity and randomized controlled trials comparing misoprostol with other induction agents in PROM. Further investigation into optimal dosing regimens, routes of administration, and subgroup analyses based on parity and cervical status would contribute to refining induction strategies. Longitudinal studies evaluating longer-term neonatal outcomes would also strengthen the evidence base guiding induction practices in PROM..

This single-center study demonstrates that induction of labour with misoprostol in women with pre-labour rupture of membranes is associated with a high likelihood of spontaneous vaginal delivery and an acceptable cesarean section rate. Maternal complications, including uterine hyperstimulation, postpartum hemorrhage, and postpartum fever, were observed at manageable levels, while neonatal outcomes—particularly NICU admissions—did not differ significantly by mode of delivery. The absence of a significant association between maternal age and delivery mode, together with the observed trend toward higher cesarean rates at advancing gestational ages, underscores the importance of individualized induction strategies. Overall, these findings support the effectiveness and safety of low-dose misoprostol as an induction agent for PROM when administered using standardized protocols and appropriate intrapartum monitoring. Given its affordability, ease of administration, and favorable outcome profile, misoprostol represents a practical and evidence-based option for labour induction, particularly in resource-limited and high-volume tertiary care settings. Further multicenter and comparative studies are warranted to refine induction protocols, optimize patient selection, and evaluate longer-term maternal and neonatal outcomes..

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