Maintenance tocolysis with oral micronized progesterone for prevention of preterm birth after arrested preterm labor

Objective: To evaluate the efficacy of maintenance therapy with oral micronized progesterone (OMP) for prolongation of pregnancy in cases of arrested preterm labor. Methods: Ninety women at 24-34 weeks of singleton pregnancy with intact membranes and arrested preterm labor were randomly allocated to receive OMP (n = 45) or placebo (n = 45) daily until 37 weeks or delivery, whichever was earlier. Outcome parameters were compared using Student t test, chi(2) test, Fisher exact test, and log-rank chi(2) test. Results: OMP significantly prolonged the latency period (33.29 +/- 22.16 vs 23.07 +/- 15.42 days; P = 0.013). Log-rank analysis revealed a significant difference in mean time to delivery between the 2 groups (P = 0.014). There were significantly fewer preterm births (33% vs 58%; P = 0.034) and low birth weight neonates (37% vs 64%; P = 0.017), and significantly higher mean birth weight (2.44 +/- 0.58 vs 2.14 +/- 0.47 kg; P = 0.009) in the OMP group. Perinatal outcomes and adverse effects were similar in the 2 groups. Conclusion: Maintenance tocolysis with OMP significantly prolonged pregnancy and decreased the number of preterm births. (C) 2014 Published by Elsevier Ireland Ltd. on behalf of International Federation of Gynecology and Obstetrics.