101: Do other elements of the obstetrical history provide a possible indication for progesterone supplementation? Secondary analysis from the progesterone vaginal gel trial


      Because obstetrical history can identify populations at varied risk for preterm birth, we desired to assess the utility of progesterone therapy for the prevention of recurrent preterm birth in subgroups whose risk profile varied based on element in their history.

      Study Design

      A secondary analysis was performed of women enrolled into a preterm prevention trial utilizing Procheive® 8% (90 mg) intravaginal, daily progesterone gel or placebo. Fisher′s exact test and Cochran-Mantel-Haenszel (CMH) test were utilized to compare outcomes in defined subgroups based on number of prior preterm birth and gestational age at preterm birth.


      668 women were enrolled in the trial with data available for analysis in 620 participants. Demographic characteristics were similar between the groups. The rate of preterm birth ≤32 weeks is shown in the Table. No single subgroup, based on obstetric historical factors, benefitted more than the others, P = 0.49 by CMH for each analysis.
      Tabled 1Response to Progesterone Therapy Based on Elements of Obstetrical History
      Number of PTBsTreated, n (%)Placebo, n (%)P value
      Single (n=462)20 of 236 (8.5)21 of 226 (9.3).870
      Multiple (n=152)10 of 73 (13.7)15 of 79 (19.0).512
      Timing of Prior PTBs
      <28 weeks (n=160)14 of 81 (17.3)13 of 79 (16.5)1.0
      28+0 to 31+6 (n=168)10 of 80 (12.5)11 of 88 (12.5)1.0
      ≥32 weeks (n=262)5 of 138 (3.6)10 of 124 (8.1).182


      Utilizing a particular element of obstetrical history to define an indication for progesterone supplementation is not supported by these data.