527 Is there an association between postoperative cervical length after cerclage and gestational age at delivery?

Abstract

Ultrasound (US) surveillance of cervical length after US and physical exam (PE) indicated cerclage has been used to attempt to identify women at highest risk for spontaneous preterm birth (PTB). Data is limited regarding the change in cervical length (CL) after cerclage placement and timing of delivery. The objectives of this study were to determine if there is an association between change in CL (difference in CL measurement prior to and post cerclage placement) and gestational age (GA) at delivery in women undergoing US or PE indicated cerclage and if there is a cutoff in CL change predictive of delivery at term. This was a retrospective study of singleton pregnancies who underwent US or PE indicated cerclage between 7/2017 and 6/2019. Patients were excluded if there was history of prior PTB, multiple gestation, placenta or vasa previa, history indicated cerclage, known fetal chromosomal or structural abnormality, or incomplete records. The Spearman correlation coefficient was used to evaluate the relationship between the change in CL and GA at delivery and the change in CL and weeks gained in pregnancy. A ROC curve was generated to determine if there was a change in CL predictive of delivery at term. 43 patients met inclusion criteria. 77% (n=33) delivered at term and 23% (n=10) delivered preterm. There was no significant correlation between change in CL and GA at delivery (Spearman correlation coefficient = 0.16, p<0.32) or between change in CL and weeks gained in pregnancy (Spearman correlation coefficient = 0.05, p<0.76). A gain in CL of ≥1.4 cm after cerclage placement was associated with delivery at term (Figure 1). The change in CL after cerclage placement was not associated with GA at delivery or prolongation of pregnancy. The majority of patients who received US or PE indicated cerclage delivered at term. A gain in CL of ≥1.4 cm was associated with delivery at term. This information may be used to appropriately counsel patients undergoing US or PE indicated cerclage.