Cervical funneling or intra‐amniotic debris and preterm birth in nulliparous women with midtrimester cervical length less than 30 mm

ABSTRACT Objective To evaluate whether the presence of cervical funneling or intra‐amniotic debris identified in the second trimester is associated with a higher rate of preterm birth (PTB) in asymptomatic nulliparous pregnant women with a midtrimester cervical length (CL) less than 30 mm (i.e. below the 10th percentile). Methods This was a secondary cohort analysis of data from a multicenter trial in nulliparous women between 16 and 22 weeks' gestation with a singleton gestation and CL less than 30 mm on transvaginal ultrasound, randomized to treatment with either 17‐alpha‐hydroxyprogesterone caproate or placebo. Sonographers were centrally certified in CL measurement, as well as in identification of intra‐amniotic debris and cervical funneling. Univariable and multivariable analysis was performed to assess the associations of cervical funneling and intra‐amniotic debris with PTB. Results Of the 657 women randomized, 112 (17%) had cervical funneling only, 33 (5%) had intra‐amniotic debris only and 45 (7%) had both on second‐trimester ultrasound. Women with either of these findings had a shorter median CL than those without (21.0 mm vs 26.4 mm; P