Fillers POEM

Progestins prevent recurrence of preterm birth

BMJ 2005; 330 doi: (Published 02 June 2005) Cite this as: BMJ 2005;330:0-f

Question Are progestational agents effective in preventing preterm birth?

Synopsis Rates of preterm births have not decreased in the past two decades. Early research on the use of progestational agents to prevent preterm birth had variable results. Recent well designed clinical trials have shown more consistently favourable results. In this meta-analysis the authors sought to quantify an estimate of benefit using rigorous meta-analytic methodology. Specific search methods, inclusion criteria, independent assessment of review and evaluation, discussion of publication bias, and homogeneity versus heterogeneity were all well described. Ten randomised controlled trials with 1339 participants met inclusion criteria. Of these, eight used 17α-hydroxyprogesterone and two used other forms of progesterone. Women included in the studies were most often believed to be at risk for preterm delivery because of a history of previous preterm birth or multiple spontaneous abortions. The rate of preterm delivery before 37 weeks' gestation was lower in women receiving a progestational agent (26% v 36%; odds ratio (OR) = 0.45; number needed to treat (NNT) = 10; 95% CI 6 to 24). Likewise, birth weight < 2500 g was less common if women received a progestational agent (20% v 28%; OR = 0.50; NNT = 12; 7 to 43). Perinatal mortality was not lowered, but the study may not have been large enough to find a difference if one exists. No difference in rates of respiratory distress syndrome was observed.

Bottom line For pregnant women with a history of preterm birth or multiple spontaneous abortions, progestins (17α-hydroxyprogesterone and other forms of progesterone) reduce the risk of preterm birth and corresponding low birth weight. Future trials should directly compare different agents.

Level of evidence 1a (see Systematic reviews (with homogeneity) of randomised controlled trials.

Sanchez-Ramos L, Kaunitz AM, Delke I. Progestational agents to prevent preterm birth: a meta-analysis of randomized controlled trials. Obstet Gynecol 2005;105: 273-9.

©infoPOEMs 1992-2003


  • * Patient-Oriented Evidence that Matters. See editorial (BMJ 2002;325: 983

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