An evaluation of prostaglandin E2 vaginal gel use in practice

The purpose of this study was to investigate the effectiveness of prostaglandin E2 vaginal gel as used in practice, rather than its efficacy as assessed in randomised, controlled, clinical trials. This product is used to ripen the cervix prior to induction of labour, sometimes making unnecessary the use of the standard treatment for induction, artificial rupture of the membranes (ARM) plus oxytocin. In this study, effectiveness of the gel was assessed in terms of changes in mode of delivery, and in particular the risk of Caesarean section.

An historical control was used and the risk of Caesarean section for women induced in the 1990/91 (before the introduction of the gel) was compared with that for women induced in 1992/93 (after the introduction of the gel). Maternal characteristics which may have been different in the two groups and factors which might influence the risk of Caesarean section were controlled for statistically using logistic regression, thus reducing any bias towards one group.

After adjusting for the factors which had a significant effect on the process of labour from induction to birth, it was found that the risk of Caesarean section was not significantly lower in the 1992/93-time period, when the gel was in regular use, from that in the 2 years prior to its introduction (Odds ratio 1.09, CI95% 0.88, 1.36).

Following the introduction of PGE2 gel, no difference in effectiveness, as measured in terms of mode of delivery, was detected in this study of practice, which included patients with more complex obstetric problems.