Tehran University Medical Journal

Background: Preterm labor is a major contributor to neonatal morbidity and mortality and results in increased obstetric and pediatric care costs. The purpose of this study was to assess the effects of vaginal progesterone for maintenance therapy following treatment of threatened preterm labor for preventing preterm birth.
Methods: The study included 70 singleton pregnant women with preterm labor with intact membranes. Patients were randomized to receive either maintenance vaginal progesterone therapy (n=37) administered (400 mg) daily or no treatment (controls, n=33) after discontinuation of acute intravenous tocolysis.
Results: The two groups were similar with at respect to maternal age, race, parity, gestational age at admission, bishop score, and preterm delivery risk factors .Compared to the control group, the mean ±SD time gained from initiation of maintenance therapy to delivery (36/1117/9 versus 24/5227/2) (meanSD) days, p=0.037) and the gestational age at delivery (36.071.56 vs. 34.51.3 weeks, p=0.041) were higher in the vaginal progesterone maintenance therapy group. No significant differences were found with recurrent preterm labor 13 (35.1%) versus 19 (57.6%), p=0.092. Respiratory distress syndrome 4 (10.8%) versus 12 (36.4%) p=0.021, Low birth weight10 (27%) versus, 17 (51.5%) p=0.04, birth weight (3101.54±587.9gr versus r 2609.39±662.9gr, p=0.002) were significantly different between the two groups.
Conclusion: The gestational age and time gained from initiation of maintenance therapy to delivery were longer in women receiving vaginal maintenance tocolysis with progesterone and improve perinatal outcomes. However, maintenance therapy did not decrease the recurrence of preterm labor episodes.