Progestational agents for treating threatened or established preterm labour

Abstract

Background: Prematurity is a leading cause of perinatal morbidity and mortality in many countries. Studies of various tocolytic agents have shown mixed results with little effect in improving pregnancy duration and insufficient data to confirm a definite beneficial effect on neonatal morbidity or mortality. Progesterone is known to have an inhibitory effect on uterine contractility and is thought to play a key role in the maintenance of pregnancy until term. Some investigators looked at the use of progestational agents for the treatment of threatened or established preterm labour. We surveyed the literature for studies on this subject with a view to performing a meta-analysis in order to assess the efficacy of progestational agents in the treatment of threatened or established preterm labour.

Objectives: To determine if the use of progestational agents is effective as a form of treatment or co-treatment for women with threatened or established preterm labour with intact membranes.

Search strategy: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (March 2009), CENTRAL (The Cochrane Library 2009, Issue 1), MEDLINE (1966 to January 2009) and EMBASE (1974 to January 2009). We checked references of articles and communicated with authors and pharmaceutical industry.

Selection criteria: Randomised controlled trials which compared progestational agents, given either alone or in combination with other tocolytics, with a control group receiving another tocolytic, placebo or no treatment, for the treatment of preterm labour.

Data collection and analysis: Two review authors independently extracted data and assessed trial quality.

Main results: There are some data suggesting that the use of progestational agent resulted in a reduction of preterm deliveries at less than 37 weeks of gestation. The use of progestational agent may also attenuate the shortening of cervical length and reduce the frequency of uterine contractions. However, the analysis was limited by the small number of available studies. This review included four studies. However, the number of participants in each included study ranged from 35 to 60 which limits the power of the meta-analysis.

Authors' conclusions: Currently, there is insufficient evidence to advocate progestational agents as a tocolytic agents for women presenting with preterm labour.