884 Adjuvant vaginal progesterone after cerclage in patients without a prior spontaneous preterm birth

Abstract

To determine if vaginal progesterone after cerclage for cervical length (CL) <10mm or cervical dilation reduces spontaneous preterm birth (sPTB) <34 weeks’ gestation compared to cerclage alone in patients without a prior sPTB. A retrospective cohort study of singleton, non-anomalous pregnancies, without a prior sPTB with cerclage placement at one tertiary care center from 2015-2019. We identified patients with current procedural terminology codes for cerclage. Cerclage indications included CL <10mm on transvaginal ultrasound or cervical dilation. Exposure was defined as cerclage plus vaginal progesterone postoperatively and unexposed as cerclage alone. Decision for vaginal progesterone after cerclage was based on physician preference and analyzed as intent-to-treat. The primary outcome was sPTB <34 weeks’ gestation. Secondary outcomes included sPTB <28 and <37 weeks' gestation. We compared groups with Fisher’s exact, Chi-square, or Wilcoxon rank-sum tests. We included 66 patients, with 39 (59%) in the cerclage plus vaginal progesterone group and 27 (41%) in the cerclage alone group. Baseline characteristics, cerclage indication, technique, and gestational age at placement were similar between groups. The cerclage plus vaginal progesterone group was less likely to deliver at <28 (5% vs. 22%, p = 0.06), <34 (21% vs. 33%, p = 0.24), and <37 (28% vs. 41%, p = 0.29) weeks’ gestation compared to the cerclage alone group; however, the findings were not statistically significant (Table 1; Figure 1). Cerclage plus vaginal progesterone was not associated with increased risk of neonatal intensive care unit admission, chorioamnionitis, or neonatal sepsis (Table 1). In patients without a prior sPTB, cerclage plus vaginal progesterone compared to cerclage alone was associated with a decreased risk of sPTB at all gestational ages studied; however, these findings were not statistically significant. Contrary to popular thought, cerclage plus vaginal progesterone was not associated with increased risk of infection, including chorioamnionitis or neonatal sepsis.View Large Image Figure ViewerDownload Hi-res image Download (PPT)