Serial cervical‐length measurements after first episode of threatened preterm labor improve prediction of spontaneous delivery prior to 37weeks' gestation

ObjectiveTo assess whether repeat cervical‐length (CL) measurement in women discharged from hospital after their first episode of threatened preterm labor can predict their risk of spontaneous preterm birth.MethodsThis was a secondary analysis of a randomized controlled trial of maintenance tocolysis, in which CL was measured on transvaginal ultrasound at the time of hospital discharge and after 2, 4, 8 and 12 weeks, in women who remained undelivered after their first episode of threatened preterm labor. After univariate analysis, multivariate logistic regression analysis was used to assess whether CL