Induction of labor in continuing pregnancies

Comparative study of second-line labor induction methods in patients with unfavorable cervix after first-line low-dose oral misoprostol

OBJECTIVE

The present study aimed to evaluate low-dose oral misoprostol induction, and compare different methods used in second-line induction in patients with a Bishop score less than 6.

METHODS

This retrospective study analyzed the medical history and courses of pregnancy of all patients induced with first-line of low-dose oral misoprostol (50 μg every 4 h with a total of 200 μg/24 h) from April 2021 to June 2022 in a university hospital center, and reported outcomes according to the second-line method of induction.

RESULTS

Among 437 labor inductions with low-dose oral misoprostol, 120 patients required a second-line induction. Predictive factors of first-line failure were higher body mass index (P = 0.011), absence of premature rupture of membranes (P = 0.021) and earlier term of pregnancy (P < 0.001). Regarding second methods of induction of labor, time from induction to delivery was shorter in the oxytocin group than the dinoprostone and misoprostol groups (24.0 vs. 41 and 51.0 h, respectively; P < 0.001), and was also significantly shorter in the dinoprostone than the misoprostol group (P = 0.048). Cesarean section rates did not differ between the three groups (P = 0.651). There were no clinically significant differences in adverse events between the groups.

CONCLUSION

Normal body mass index, previous rupture of membranes and later term of induction of labor were the three favoring success factors during first-line oral misoprostol. In cases of a Bishop score <6, oxytocin may be the best option to reduce duration to delivery, with the same maternal-fetal outcomes, including a similar rate of vaginal delivery.

Comparing the effectiveness and safety of Dinoprostone vaginal insert and double-balloon catheter as cervical ripening treatments in Chinese patients

Background

This retrospective study was to compare the effectiveness and safety of Dinoprostone vaginal insert vs. double-balloon catheter as cervical ripening agents for labor induction.

Methods

Pregnant women with Bishop score <7, who received either Dinoprostone vaginal insert 10 mg or Cook's double-balloon catheter for labor induction, were studied. The primary outcome was the rate of vaginal delivery within 48 h; the secondary outcomes were the proportion of women undergoing cesarean section, labor duration, oxytocin administration, changes in Bishop score, complications during labor, and maternal/neonatal outcomes.

Results

One hundred and eighty-two women were included in Dinoprostone group, and 199 women were in double-balloon catheter group. The rate of vaginal delivery within 48 h was significantly higher in Dinoprostone group than that in double-balloon catheter group (90.11% vs. 75.38%, P = 0.0002). There were 18 cesarean section deliveries (9.89%) in Dinoprostone group and 49 cesarean section deliveries (24.62%) in double-balloon catheter group, with significant differences between two groups (P = 0.0002). The duration of labor was higher in Dinoprostone group, while the augmentation with oxytocin was significantly lower in Dinoprostone group than in double-balloon catheter group (all P < 0.0001). The incidence of chorioamnionitis was significantly higher in double-balloon catheter group as compared with Dinoprostone group (0 vs. 12, P = 0.0005), while neonatal outcomes were similar in two groups.

Conclusion

Dinoprostone vaginal insert as cervical ripening agent is more effective for labor induction and with lower risks of chorioamnionitis as compared with double balloon catheter in Chinese populations.

Labour induction in twin pregnancies

Medically-indicated deliveries are common in twin pregnancies given the increased risk of various obstetric complications in twin compared to singleton pregnancies, mainly hypertensive disorders of pregnancy and foetal growth restriction. Due to the unique characteristics of twin pregnancies, the success rates and safety of labour induction may be different than in singleton pregnancies. However, while there are abundant data regarding induction of labour in singleton pregnancies, the efficacy and safety of labour induction in twin pregnancies have been far less studied. In the current manuscript we summarize available data on various aspects of labour induction in twin pregnancies including incidence, success rate, prognostic factors, safety and methods for labour induction in twins. This information may assist healthcare providers in counselling patients with twin pregnancies when labour induction is indicated.

Trends and characteristics of women undergoing induction of labour in a tertiary hospital setting: A cross-sectional study

BACKGROUND

In many well-resourced countries, rising rates of intervention are being observed during pregnancy, labour and childbirth with induction of labour (IOL) fast becoming one of the most common. In Australia, the rate of induction of labour has increased by over 30% since 2007, and today one in three women have their labours induced. We do not however have a good understanding of the contribution of specific obstetric populations to this trend.

METHODS

We examine the contribution of specific obstetric populations to induction of labour over a six-year period at one tertiary maternity service, using the Nippita classification system. Average Annual Percentage Changes (AAPC) were calculated along with 95% confidence intervals and P values set at 0.05.

RESULTS

The overall rate of induction of labour increased from 21.3% in 2012 to 30.9% in 2017, representing an Average Annual Percent Change of 8.1, P<0.0001 (95% CI 7-9.6). The greatest AAPC was seen in group 5 (parous, no previous caesarean section, 39-40 weeks, single cephalic), followed by group 2 (nulliparous, 39-40 weeks, single cephalic) and 1 (nulliparous, 37-38 weeks, single cephalic).

CONCLUSIONS

The use of the Nippita classification system allowed for standardised comparison across timepoints, facilitating identification of the subpopulations driving changes in rates of induction of labour. Rates of induction of labour saw a year on year increase which in this maternity service, it is not being driven by post-dates pregnancies. Further work is required to understand the role of other potential contributors such as diabetes.