Efficacy and safety of extra amniotic insertion of Foley catheter verses intra cervical application of PGE2 gel in pre-induction cervical ripening among primi mothers at 40 weeks +5 days or beyond – a randomized controlled study

Abstract

Objectives: The aim of this study was to compare the efficacy, safety and side effects of extra amniotic insertion of Foley catheter and intra-cervical application of prostaglandin E 2 vaginal gel (PGE 2) among primi mothers who were 40 weeks or beyond, as a pre induction ripening method. Method: This randomized study was conducted at Obstetrics ward, Kandy Teaching Hospital, between August 2010 to March 2011. Hundred and fourty-five mothers were randomly allocated to two groups. Age, BMI, period of gestation and, pre ripening Bishop's score were measured as base line features to compare two groups. Group A (n=72) was ripened with prostaglandin E 2 vaginal gel (Dinoprostone 0.5 mg) and Group B (n=73) with insertion of Foley catheter (18 G and filled with 70 ml of distilled water) without tension. Primary outcome measures were spontaneous onset of labour within 24 hours and the mode of delivery. Maternal and fetal adverse effects were measured as secondary outcomes. Maternal age, period of gestation, pre induction cervical ripening Bishop's score and maternal BMI were compared as baseline characters of two groups. As measures of efficacy, spontaneous onset of labour, vaginal delivery rate and caesarean section rate were compared. Maternal and fetal adverse effects were used to compare the safety of the two methods. Results: Mean maternal ages were 27 and 28 years in group A and B respectively. Mean period of gestation was 40 weeks +5 days in both groups. Mean pre ripening Bishop's scores in group A was 4.24 ± 0.41and 4.63 ± 0.38 for group B. BMI of group A was 26.9 ± 1.43Kg/m 2 and 27.2 ± Kg/m 2 in group B. However, a significant difference was not observed between these two groups. While mothers in group A had 30.5% spontaneous onset of labour, only 24.6% mothers went into spontaneous onset of labour (p=0.78) in group B. Vaginal delivery rates were 77% and 72% in group A and B respectively (p=0.78). Respective Caesarean section rates of group A and group B were 22.8% and 27% (p=0.64). Mothers who had PGE 2 had significantly higher chances of experiencing side effects (44%) in compared to mothers who had Foley catheters (22%) (p=0.016). Mothers who had PGE 2 had significantly higher rates of uterine hyper-stimulation (p=0.01), nausea and vomiting (p=0.03) and fever more than 38 C° (p=0.03) while post-partum haemorrhage was not significant (p=0.071). Similar rates of meconium at ARM, fetal distress, APGAR<7 at 5 min and SBU admissions were experienced by fetuses and neonates in both groups (p=0.63). Conclusion: Insertion of Foley catheter to extra amniotic space is as effective as intra-cervical application of PGE 2 gel for pre induction cervical ripening. Due to lower maternal adverse effects, extra amniotic insertion of Foley catheter is safer than intra-cervical application of PGE 2 gel.