Identify variables associated with cervical length (CL) changes in women with a short CL at time of second trimester anatomy scan.METHODS:
Retrospective analysis of patients diagnosed with short CL at time of routine anatomy scan, between 16–26 weeks from October, 2012–June, 2015. Short CL was defined as <25 mm in high risk (HR) or <20 mm in low risk (LR) patients. Patients with history of spontaneous preterm delivery or 1+ 2nd trimester spontaneous abortions defined as HR. Change in CL calculated using difference between initial CL and subsequent measurement. Regression analysis performed with stepwise selection of variables, to assess for variables that are predictive of cervical change.RESULTS:
404 (4.6%)/8,732 scanned found to have short CL. Data incomplete for 208 were excluded from the analysis. Mean maternal age 28.7 and mean gestational age at diagnosis 21w1d. Mean Body Mass Index (BMI) 29.7 kg/m2 (14–57) and mean pregnancy weight gain 19.6 lbs (0–54). 25% were HR and 75% LR. The most common interventions were vaginal progesterone (38%) and cerclage (16%), with 40% expectant. Mean change in CL for this cohort between both scans was a decrease by 14 mm. Using regression analysis, BMI was predictive of CL shortening (P=.052). For every 10 BMI points, the cervix shortened by 1.8 mm.CONCLUSION:
In this cohort of patients with short CL identified at time of routine anatomy scan, the BMI was predictive of further CL shortening. These results may imply a need for closer CL surveillance in patients with higher BMI who are found to have a short CL.