Vaginal progesterone after tocolytic therapy in threatened preterm labor

The aim of this study was retrospective evaluation of progesterone efficacy in pregnant patients with preterm uterine contractions.

190 women hospitalized at 1st Department of Obstetrics and Gynecology, Medical University of Warsaw, in 2007-2010, with symptoms of threatened preterm labor were enrolled in the study. 94 women were treated with tocolytics and steroids (control group), while 96 women received additionally 200 mg of progesterone vaginally until delivery or 34th weeks of gestation (progesterone group).

The mean gestational age at admission was 27 weeks in progesterone group and 28 weeks in control group. Cervical length was similar in both groups. There were no significant differences in week of delivery between groups, but the progesterone group had significant increase in prolongation of pregnancy (7.6 versus 6.3 weeks, p = 0.039). Vaginal progesterone was associated with reduction of delivery before 34 weeks (9.8% versus 35.3%; p = 0.002) and neonatal birth weight <1500 g (3.2% versus 20.6%; p = 0.011) only in patients presenting with uterine contractions after 27 weeks.

The administration of vaginal progesterone after tocolysis in threatened preterm labor is associated with prolongation of pregnancy. The reduction of deliveries before 34 weeks was observed in patients presenting with contractions after 27 weeks gestation.