Biochemical and Clinical Evaluation of the Efficiency of Intracervical Extraamniotic Prostaglandin F2α and Intravenous Oxytocin Infusion to Induce Labour at Term
Authors: Kaminski Krzysztof , Rechberger Tomasz , Oleszczuk Jan , Jakowicki Jerzy , Oleszczuk Jaroslaw 
Published: February 2008

EDITORIAL COMMENT: We accepted this paper for publication partly because it is a careful study comparing intracervical prostaglandin F2<x and intravenous oxytocin for induction of labour, which concludes that prostaglandin F2α has many advantages as was reported by MacLennan and his colleagues in the May edition of this journal. Readers are referred to the editorial comment published with this article. Although it is wise to believe that all oxytocic agents are potentially dangerous, especially in multiparas, the editorial committee believes these papers justify reconsideration of the use of prostaglandin F2αfor induction of labour since there are certainly examples of uterine hypertonus causing important complications with the use of prostaglandin E2. One reviewer made the comment that the vast majority of women with a cervical Bishop score of between 4 and 8 would be suitable for amniotomy alone with many coming into spontaneous labour and needing no other form of uterine stimulant. What clinicians require is a comparison of prostaglandin F2α versus prostaglandin E2for induction of labour when indicated in women with an unfavourable cervix (Bishop score ≤4).

This paper will also interest readers because of the data concerning cervical ripening and the importance of collagenase and elastase activity in the lower uterine segment in women with induction of labour by the 2 methods compared, in contrast with control women requiring Caesarean section electively (no labour) or after spontaneous labour.

Summary: A prospective randomized study of 296 patients was undertaken to evaluate the efficiency of 15 mg prostaglandin F2α (PGF2α) suspended in tylose gel and applied intracervically for labour induction. The control group was treated with standard oxytocin intravenous infusion. Results indicated that local PGF2α was superior to oxytocin therapy in shortening the duration of labour (6.3 ± 2.3 versus 8.1 ± 2.6 hours, p <0.05). Only 19% of the patients treated with PGF2α required oxytocin augmentation during labour. Our data suggest that PGF2α treatment is associated with few maternal side‐effects, few failed inductions, a low operative delivery rate and favourable neonatal outcome. To investigate the influence of PGF2α for labour promotion we have measured interstitial collagenase and elastase activity in the lower uterine segment after both methods of labour induction. The total collagenase activity was 22 times higher in tissue samples obtained from patients in active spontaneous and oxytocin‐induced labour, compared with women not in labour (at term) (p < 0.001). The total interstitial elastase activity was 2‐fold higher in women in active labour than in patients at term (p <0.03). A significantly higher collagenase and elastase activity was observed in uterine specimens obtained from patients treated with PGF2α compared to oxytocin, and this indicates that cervical collagen may be digested more quickly in the presence of exogenous prostaglandin F2α.