American Journal of Obstetrics and Gynecology
Poster session IClinical obstetrics, neonatology, physiology-endocrinology98: Mid-pregnancy cervical length as a predictor of preterm birth in multiple pregnancies
Section snippets
Objective
Short mid-pregnancy cervical length has been shown in previous studies to be a strong predictor of preterm birth in both singleton and multiple pregnancies. We evaluated the predictive value of second trimester cervical length for preterm birth in multiple pregnancies and developed a prediction model using several other variables.
Study Design
This was a secondary analysis of a trial on progesterone treatment for the prevention of preterm birth in multiple pregnancies (the AMPHIA trial, ISRCTN40512715). We performed a univariable analysis for the risk of preterm birth using age, BMI, ethnicity, education level, parity, smoking, alcohol use, fertility treatment, number of multiples, chorionicity and cervical length. The final predictors of the multivariable models were identified by backward stepwise selection using Akaike's
Results
Out of the 662 women who participated in the trial, 347 (52%) delivered before 37 weeks and 79 (12%) before 32 weeks. Backward stepwise selection yielded that nulliparity (OR 1.5; 95% CI 1.1 to 2.0), monochorionicity (OR 2.0; 95% CI 1.3-3.0) and cervical length (OR 1.5; 95% CI 0.8 to 2.8 per centimeter increase) were independent predictors of preterm birth before 37 weeks. For preterm birth before 32 weeks, independent predictors were high educational level (OR 0.6; 95% CI 0.3-1.1), nulliparity
Conclusions
As shown in previous studies, short cervical length in mid-pregnancy is a risk factor for preterm birth. This risk is further increased by nulliparity, monochorionicity and low educational level.