9: 17-Alpha-hydroxyprogesterone caproate for the prevention of preterm birth in women with prior preterm birth and a short cervical length


      To evaluate 17-alphahydroxy-progesterone caproate (17P) for the prevention of preterm birth (PTB) in women with prior spontaneous PTB (SPTB) and a short cervical length (CL).

      Study Design

      This is a planned secondary analysis of the NICHD-sponsored randomized trial evaluating cerclage for women with singleton gestations, prior SPTB (17-33 6/7 wks), and short CL < 25 mm measured between 16 and 22 6/7 wks. Women were stratified at randomization to the intent to use or not use 17P. Subsequent use of 17P was recorded. The effect of 17P use was analyzed separately for the cerclage and no cerclage groups. The primary outcome was PTB < 35 wks. Secondary outcomes included birth < 7 days from randomization, PTB < 24 and < 37 wks, and perinatal death. Maternal age, race, smoking, drug use, shortest CL and intent to use 17P were considered as possible confounders.


      302 women were randomized and 300 were available for analysis. Of these, 148 were randomized to cerclage and 152 to no cerclage. 17P had no effect on PTB < 35 wks in either the cerclage (p=0.64) or the no cerclage (p=0.51) groups. Shortest CL was a significant variable in both the cerclage and no cerclage multiple logistic regression models. The odds of PTB <24 wks (OR=0.08, p=0.0022) and perinatal death (OR=0.14, p=0.0029) were significantly lower for those with 17P in the no cerclage group. See Tables 1 and 2.


      17P in women with a prior SPTB and a short CL < 25 mm at 16-22 6/7 weeks is not associated with PTB < 35 wks. In the absence of cerclage, 17P may reduce previable birth and perinatal mortality.