Progesterone Gel Prevents Preterm Birth in Women with Short Cervix and Reduces Neonatal Respiratory Distress

DynaMed Weekly Update - Volume 6, Issue 14

The risk of preterm birth is increased in women with a short cervix. Intramuscular or vaginal progesterone appears effective for reducing premature delivery, but data on neonatal outcomes have been limited (Cochrane Database Syst Rev 2009 Apr 15;(2):CD004947). A recent randomized trial evaluated a new progesterone gel in 465 women at 19 to 23 6/7 weeks gestational age. Women with singleton pregnancy and cervical length 10-20 mm on sonography were randomized to a vaginal gel with progesterone 8% vs. placebo until 36 6/7 weeks, rupture of membranes or delivery. The progesterone group had significantly reduced rates of preterm birth before 28 weeks (5.1% vs. 10.3%, p = 0.04, NNT 20), before 33 weeks (8.9% vs. 16.1%, p = 0.02, NNT 14), and before 35 weeks (14.5% vs. 23.3%, p = 0.02, NNT 12) (level 1 [likely reliable] evidence). Babies born to mothers in the progesterone group had reduced risk of neonatal respiratory distress syndrome (3% vs. 7.6%, p = 0.03, NNT 22) and reduced incidence of birth weight < 1,500 g (6.4% vs. 13.6%, p = 0.01, NNT 14). There were no significant differences in neonatal mortality (1.3% vs. 2.2%), days in neonatal intensive care unit, or in birth weight < 2,500 g. There were also no significant differences in adverse events (Ultrasound Obstet Gynecol 2011 Apr 6 early online).

For more information, see the Preterm labor topic in DynaMed.