Does the presence or absence of funneling influence the incidence of preterm birth in women with a short cervical length?

Abstract

OF PRETERM BIRTH IN WOMEN WITH A SHORT CERVICAL LENGTH? VINCENZO BERGHELLA, AMANDA ROMAN, Thomas Jefferson University, Obstetrics and Gynecology, Philadelphia, Pennsylvania OBJECTIVE: To estimate if the presence or absence of funneling influence the incidence of spontaneous preterm birth (SPTB) in women with a short cervical length (CL) on transvaginal ultrasound (TVU). STUDY DESIGN: Women identified to have a short CL on TVU between 14 0/7 and 23 6/7 weeks at Thomas Jefferson University were reviewed between 1995 and June 2005. A short CL was defined as !25 mm. Funneling was defined as the ratio of funnel length over funnel length plus functional CL, and considered present if this ratio was O25%. Exclusion criteria were major fetal anomaly, prophylactic cerclage, indicated preterm birth, and multiple gestation. Cases were defined as those women with a short CL with funneling, while controls were women with short CL without funneling. Primary outcome was SPTB !35weeks. RESULTS: Two hundred forty-three women with singleton gestations and a short CL! 25 mm between 14 23 6/7 weeks were identified. Seventy-eight women with funneling were matched and compared to 78 women with no funneling. The two groups were similar in demographics and risk factors, including CL, gestational age (GA) at short CL, and prior SPTB (Table). The outcomes of SPTB ! 35 weeks, SPTB !32 weeks, and PPROM were not different in these two groups (Table). CONCLUSION: Funneling in women with a short CL ! 25 mm between 14 0/7 and 23 6/7 weeks did not increase the incidence of SPTB compared to similar women with no funneling. The risk of SPTB in women with a short CL should therefore be estimated just from the degree of cervical shortening.