The effect of treatment with 17 alpha-hydroxyprogesterone caproate on changes in cervical length over time

OBJECTIVE: The purpose of this study was to examine whether women who were treated with 17 alpha-hydroxyprogesterone caproate (17-OHPC) to prevent recurrent preterm birth experienced a change in cervical shortening over time, compared with women who were not treated. STUDY DESIGN: We conducted a retrospective exposure cohort study of women who were enrolled in a prematurity prevention clinic from 1999-2008 with a singleton pregnancy with >= 1 previous spontaneous preterm births (<37 weeks of gestation) who underwent >= 2 cervical length measurements by endovaginal ultrasound. RESULTS: Of 200 women, 105 women received treatment with 17-OHPC; 95 women did not. Women who were treated with 17-OHPC were more likely to have experienced a previous preterm birth (26.0 vs 27.8 weeks; P = .01) than those who were not treated with 17-OHPC. There was no difference in the average weekly change in cervical length among women treated with 17-OHPC, compared with those who were not, after adjustment for covariates (0.79 mm/week; 95% confidence interval, -1.18 to 2.76). CONCLUSION: There was no difference in the average weekly change in cervical length measurements over time in women who underwent 17-OHPC treatment, compared with those who were not treated.