469 Mid-trimester asymptomatic cervical shortening in nulliparas and obstetric outcome

Abstract

Routine mid-trimester cervical length (CL) screening has led to increased patient referral due to asymptomatic cervical shortening (ACS). In the current study we aimed to compare preterm birth (PTB) rates and neonatal outcomes of women with ASC compared to symptomatic cervical shortening (SCS) and normal cervical length (NCL). A retrospective case-control study of women admitted due to ACS in a university-affiliated medical centre between January 2008 to April 2020. ACS was defined as CL≤ 25mm at the mid-trimester routine anatomy scan. CL measurements were repeated 24 hours from admission by a designated sonographer. Women with a short cervix were treated with vaginal progesterone 200 mg daily up to 36 weeks' gestation. The primary outcome was gestational age at delivery. Secondary outcomes included arterial cord pH, 5-minute Apgar score, need for NICU admission and a composite of adverse neonatal outcomes including RDS, NEC, IVH and neonatal sepsis. The study included 2615 women. The rate of PTB was significantly lower in women with ACS compared to SCS and similar compared to NCL (11.1% vs. 37.9%, p<0.0001 and 11.1% vs. 9.2%, p>0.05, respectively). A similar trend was observed in the NICU admission rate (15.1% vs. 41.8%, p<0.0001 and 15.1% vs. 11.7%, p>0.05, respectively). The total length of hospitalization throughout pregnancy was similar between ACS and SCS and significantly higher compared to NCL (26.3±5.8 days vs. 22.4±3.5 days, p>0.05 and 26.3±5.8 days vs. 1.2±0.7 days, p<0.0001, respectively). The rate of the composite outcome was significantly lower in the ACS compared to SCS group but significantly higher compared to the NCL group (3.4% vs. 14.2%, p<0.0001 and 3.4% vs. 1.6%, p=0.021, respectively). ACS diagnosed at mid-trimester is not associated with an increased PTB rate in nulliparous women treated with vaginal progesterone thereafter. This alarming diagnosis leads to unjustified long hospitalization periods and over-treatment.View Large Image Figure ViewerDownload Hi-res image Download (PPT)