Selection of Appropriate Prostaglandin for the Induction of Labor at Term is More Predictive for the Achievement of Delivery within 24 Hours than Pre-assessed Cervical Parameters - A Prospective, Randomized Trial

Abstract

Objective: To compare the efficacy of vaginal misoprostol and dinoprostone gel for induction of labor at term and to evaluate the predictive value of pre-assessed Bishop score and sonographic estimated cervical length. Methods: One hundred and seven patients were prospectively randomized to receive either 50 µg misoprostol vaginally every 12 hours, or 2 mg of dinoprostone gel for nulliparae with an unfavorable cervix. 1 mg was given in case of multiparity or nulliparity with a Bishop score of > 5, according to the RCOG guidelines. Primary outcome was the achievement of vaginal delivery within 24 hours. Secondary outcome parameters included the induction to delivery interval, mode of delivery, drug related side effects, and the predictive value of the Bishop score and sonographic estimated cervical length. Results: The probability of delivering within 24 hours was more than threefold higher with misoprostol than with dinoprostone: odds ratio [OR]: 3.23; 95 percent confidence interval [CI]: 1.14 - 9.16, p: 0.03. In contrast, predictive values of both cervical parameters for delivery within 24 hours were not significant (Bishop score: [OR]: 1.28; [CI: 0.92 - 1.77], p: 0.14, cervical length: [OR]: 0.98; [CI: 0.92 - 1.03], p: 0.40). No difference was observed in the induction to delivery interval between both groups, and no correlation between cervical parameters and induction to delivery interval. Conclusion: Vaginal misoprostol is an effective, safe and cost-effective alternative to dinoprostone for cervical ripening and labor induction. The preinduced assessed cervical parameters showed poor predictive values for estimation of delivery within 24 hours and no correlation with the induction to delivery interval.

Zusammenfassung

Fragestellung: Vergleich der Effektivität von vaginal appliziertem Misoprostol versus Dinoproston zur Geburtseinleitung am Termin und Evaluierung des prädiktiven Wertes der zervikalen Parameter (Bishop-Score und sonografisch gemessene Zervixlänge). Material und Methodik: Prospektive Randomisierung von 107 Patientinnen, welche entweder 50 µg Misoprostol alle 12 Stunden oder 2 mg Dinoproston bei Nulliparität und unreifer Zervix beziehungsweise 1 mg bei Multiparität oder bei Nulliparität mit reifer Zervix (Bishop-Score > 5) nach den Richtlinien des RCOG erhielten. Primärer Outcome-Parameter war eine vaginale Geburt innerhalb von 24 Stunden. Sekundäre Outcome-Parameter beinhalteten den Intervall bis zur Geburt, die Geburtsart, medikamentöse Nebenwirkungen sowie die prädiktiven Werte des Bishop-Scores und der sonografisch gemessenen Zervixlänge. Resultate: Die Wahrscheinlichkeit einer Geburt innerhalb von 24 Stunden war in der Misoprostol-Gruppe mehr als 3-fach höher, in der Dinoproston-Gruppe: Odds Ratio [OR]: 3,23; 95 %-Konfidenzintervall [CI]: 1,14 - 9,16, p: 0,03. Die beiden zervikalen Parameter zeigten keine signifikanten prädiktiven Werte in Bezug auf eine Geburt innerhalb von 24 Stunden (Bishop-Score: [OR]: 1,28; [CI: 0,92 - 1,77], p: 0,14, Zervixlänge: [OR]: 0,98; [CI: 0,92 - 1,03], p: 0,40). Es zeigte sich kein Unterschied im Zeitrahmen der Geburtseinleitung zwischen beiden Medikamenten. Ebenso fand sich keine Korrelation zwischen dem Zeitabstand der Einleitung bis Geburt und den zervikalen Parametern. Schlussfolgerung: Vaginal appliziertes Misoprostol ist eine wirkungsvolle, sichere und kostengünstige Alternative zu Dinoproston in der Geburtseinleitung. Die vorgängig erhobenen zervikalen Parameter zeigen niedrige prädiktive Werte im Hinblick auf das Eintreten einer Geburt innerhalb von 24 Stunden und keine Korrelation mit der Zeitdauer der Einleitung bis Geburt.

Key words

pregnancy - labor - induced - misoprostol - dinoprostone - cervical length

Schlüsselwörter

Schwangerschaft - Geburt - Geburtseinleitung - Misoprostol - Dinoprostone - Zervixlänge

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