Developing and validating the Caesarean risk assessment nomogram and comparing the effect of cervical ripening balloon, evening primrose oil and misoprostol on childbirth outcomes in term pregnancies: A study protocol

AIM

To develop and validate the nomogram for risk estimation of Caesarean delivery and to compare the effect of cervical ripening balloon, evening primrose oil (EPO) and misoprostol on Bishop Score and duration of the first stage of labour.

DESIGN

The first phase is a prospective study, and the second phase is a randomized controlled trial.

METHODS

In the first phase, the nomogram will be developed and validated over 300 participants, and in the second phase, the 90 participants will be allocated to three groups: vaginal 25mcg misoprostol, vaginal 4000mg EPO and double-balloon catheter, through block randomization method. The Bishop score will be evaluated every 4 hr, and if required the same dose will be repeated. Maximum waiting time for balloon is 12 hr if not effective, the catheter will be removed, and other interventions will be done according to guidelines.

DISCUSSION

The nomogram will help informed decision-making for women undergoing an induction with an unfavourable cervix and introducing effective low-complication methods of labour induction can improve the pregnancy outcomes.

Comparison of labour induction with misoprostol and dinoprostone and characterization of uterine response based on electrohysterogram

OBJECTIVE

The objective of this study is to compare the uterine activity response between women administered dinoprostone (prostaglandin E2) and misoprostol (prostaglandin E1) for induction of labour (IOL) by analysing not only the traditional obstetric data but also the parameters extracted from uterine electrohysterogram (EHG).

METHODS

Two cohorts were defined: misoprostol (25-µg vaginal tablets; 251 women) and dinoprostone cohort (10 mg vaginal inserts; 249 women). All the mothers were induced by a medical indication of a Bishop Score < = 6.

RESULTS

The misoprostol cohort was associated with a shorter time to achieve active labour (p = .017) and vaginal delivery (p = .009) and with a higher percentage of vaginal delivery in less than 24 h in mothers with a very unfavourable cervix score (risk ratio (RR): 1.41, IC95% 1.17-1.69, p = .002). Successful inductions with misoprostol showed EHG parameter values significantly higher than basal state for amplitude and pseudo Montevideo units (PMU) 60' after drug administration, while spectral parameters significantly increased after 150'. This response was not observed in failed inductions. In the successful dinoprostone group, the duration and number of contractions increased significantly after 120', PMU did so after 180', and no significant differences were found for spectral parameters, possibly due to the slower pharmacokinetics of this drug.

CONCLUSION

Successful inductions of labour by misoprostol are associated with earlier effective contractions than in labours induced by dinoprostone.