SMFM: Progesterone Does Not Prolong Pregnancy after Successful Tocolytic Treatment

Progesterone does not reduce the risk of preterm delivery among women whose preterm labor was successfully arrested by tocolysis, results from a randomized controlled trial showed.

The open-label, multicenter study included women with singleton pregnancies admitted for an episode of preterm labor between 24 weeks and 31 weeks and 6 days, who also  had a cervical length <25mm.

All women received a course of 12 mg of betamethasone, delivered intramuscularly and repeated after 24 hours.  Women were then randomly assigned to receive either 500 mg of intramuscular 17 alpha-hydroxyprogesterone caproate (17P) twice weekly until 36 weeks or preterm delivery, or no treatment. Physicians were permitted to otherwise manage patients at their discretion, providing no progesterone was used in the control group.

Median time to delivery did not differ significantly between the 17P group and the control group (64 days and 67 days, respectively), or in the rates of delivery before 37 (39% and 38%), 34 (16% and 20%), or 32 (9% and 14%) weeks gestation.

Lead author Patrick Rozenberg noted that while some prior research indicated that 17P after tocolysis was beneficial, this study “used a less sever population than in previous studies.”

Read our complete coverage of the Society of Maternal and Fetal Medicine's 32nd Annual Meeting, including:

SMFM: LEEP Does Not Increase Risk of Preterm Birth

SMFM: Induction of Labor Reduces Trauma Risk for Large-for-Date Fetuses

SMFM: CMA Should Become the Standard for Prenatal Diagnosis