Abstract

Introduction: Though induction of labor is being practiced since 16th century it has become a relatively common procedure in modern day obstetric practice. Earlier it was being practiced mostly or predominantly for delivery of a dead fetus but in today’s modern obstetric practice indications include diverse maternal and fetal conditions where risks of continuation of pregnancy far outweighs the effects of an early delivery. Common situations where induction of labor is required include preeclampsia, intrauterine fetal death, intrauterine growth retardation, fetal distress, severe oligohydramnios and compromised maternofetal or placentofetal circulation as indicated by abnormal Doppler studies. Before the era of oxytocin induction of labour was mostly done by unreliable methods like stimulation of nipples, laxatives, purgatives and herbal tea etc but with the advent of oxytocin and newer techniques induction of labor is being done now in an effective and predictable manner. The important components of any regimen used for induction of labor include cervical ripening and augmentation of labour. The approaches for cervical ripening may include pharmacological and surgical methods. Intracervical PGE2 and Intravaginal PGE1 can be used for cervical ripening and these agents have become immensely popular because of their effectiveness in induction of labor. Though these agents have been subject of immense curiosity and research there has been a lack of evidence regarding the most appropriate route of administration and dose of PGE1 and whether it has any advantage over use of PGE2 which is most commonly used prostaglandin for the purpose of induction of labor. With this background in mind we conducted this comparative study to know the efficacy and safety of intracervical PGE2 and intravaginal PGE1 for cervical ripening and induction of labor in women who have completed 37 weeks of gestation.

Aims and Objectives

(1) To study the safety and efficacy of PGE2 gel 0.5 mg Vs low dose 25 microgram PGE1 by intravaginal route for cervical ripening and induction of labour.

(2) To assess the induction- delivery interval, maternal and fetal outcome in both the groups.

Materials and Methods: This was an analytical observational study carried out in the department of obstetrics and Gynaecology at a tertiary care centre situated in an urban area. The study was approved by institutional ethical committee. 200 pregnant patients who have completed 37 weeks of gestation and in whom induction of labor was done with either intracervical PGE2 or Intravaginal PGE1 for any indications were included in the study after considering inclusion as well as exclusion criteria. The patients were divided into 2 groups (100 patients each) on the basis of whether they received intravaginal PGE1 or intracervical PGE2. A detailed history was taken in all the patients and all of them underwent thorough general, systemic and obstetrics examination. In addition to clinical examination ultrasonography, non-stress test, pre-induction bishop’s score and cervical assessment was done in all the cases. The safety and efficacy of PGE2 gel 0.5 mg Vs low dose 25 microgram PGE1 by intravaginal route for cervical ripening and induction of labour were studied and an assessment with regards to induction- delivery interval, maternal and fetal outcome was done in both the groups.

Results: This study comprised of 200 women who had completed 37 weeks of gestation and in whom induction of labor was done with either intracervical PGE2 or Intravaginal PGE1. In PGE1 group 42% and 58% patients were multi and primigravida. While this percentage was 48% and 52% respectively in PGE2 group. The most common age group in PGE1 group was found to be 21-25 years (40%) and 26-30 years (40%) while in PGE2 the most common age group was 26-30 years (38%). Majority of the patients in both the groups belonged to gestational age of 37-38 weeks. The most common indications for induction of labor in PGE1 and PGE2 group was found to be premature rupture of membranes (29% vs 23) and postdatism (28% vs 32%). Mean Bishop score in PGE1 and PGE2 was 4.41 and 4.29 at the induction of labour. In PGE2 group 72% cases showed Bishop score of more than 6 at the end of 4 hrs while this percentage was 70 % at the end of 6 hours in PGE1 group. The mean interval time from induction to onset of labor was found to be 3.51 hrs and 5 hrs in PGE1 and PGE2 group and the difference was found to be statistically significant. Oxytocin was required in less number of patients (25%) in PGE1 group than in PGE2 group (41%) and the difference was statistically significant. Only 1 dose of PGE1 or PGE2 was required in 70% of the patients in both the groups. Mean induction to delivery time was 11.61 and 8.39 hours in PGE2 and PGE1 group respectively. The difference was statistically significant. 87% patients in PGE1 and 66%   patients in PGE2 group delivered within 12 hours after induction and the difference was found to be statistically significant. Patients in PGE1 and PGE2 group required LSCS In 26% and 16 % cases respectively and normal vaginal delivery occurred in 69% and 77%. The outcome of pregnancy in primigravida and multigravida patients didn’t show any statistically significant difference. Failure of induction and non progression of labor was more common in PGE2 group than PGE1 group while fetal distress was more common in PGE1 group though the difference was not found to be statistically significant. Analysis of maternal complications like hyper-stimulation, diarrhea, vomiting and fever showed that there was no statistically significant differences in these 2 groups as far as maternal complications were concerned. The parameters like number of patients with hyper stimulation, use of tocolytics and non-stress tests were not comparable in both the groups. Though statistically not significant adverse neonatal outcome and need for NICU admissions were more common in PGE1 than in PGE2 group. Mean APGAR scores and mean baby weights were comparable in both the groups. Lastly the analysis of cost effectiveness showed that the PGE1 was more cost effective (Rs 11.07) than PGE2 (Rs 336.7) for induction of labor and the difference in costs was found to be statistically significant.

Conclusion: Both PGE1 and PGE2 are safe for induction of labor however that intravaginal PGE1 is more efficacious and cost-effective in comparison to intracervical PGE2.

Keywords: PGE1, PGE2, Induction of labor, Maternal and Neonatal Outcome.