Transvaginal Sonographic Measuremant of cervical Length in Early Third Trimester as a Predictor of Preterm Delivery

Abstract

Transvaginal Sonographic Measuremant of cervical Length in Early Third Trimester as a Predictor of Preterm Delivery

Paiboon             Charoenchainont            MD

Phongthom      Virojchaiwong                 MD

Chumrus            Sakulpaisal                      MD

Department of Obstetrics and Gynecology, BMA Medical College and Vajira Hospital

Objective: To evaluate the cervical length, measured by transvaginal ultrasound, as the predictor of preterm labor.

Study design: Diagnostic test.

Setting: The antenatal clinic, Department of Obstetrics and Gynecology, BMA Medical College Vajira Hospital.

Subjects: A total of 301 pregnant women were studied between October 1998 and May 1999 and followed up until delivery.

Methods: Cervical length of 350 pregnant women, 28-30 weeks gestational age, were measured with transvaginal ultrasound. Only 301 cases as total subjects were followed up until delivery. Cervical length of term and preterm delivery were analysed for the correlation. Define sensitivity, specificity, positive and negative predictive value and ROC curve of cervical length as the predictors of preterm labor.

Main outcome measures: Sensitivity, specificity, positive predictive value and negative predictive value of cervical length as the predictors of preterm labor.

Results: Three hundred and one from 350 cases were followed up until delivery. Thirty nine cases were lost to follow up. Ten cases were excluded from this study due to medical complication necessitating termination of pregnancy. Two hundred and seventy two cases delivered at gestational age >37 weeks while 29 cases delivered preterm at gestational age