The Value of Late Mid-Trimester Ultrasound Cervical Assessment after Cerclage for the Prediction of Preterm Birth

Abstract

Listen

Translate article

Background: Spontaneous preterm birth constitutes a significant obstetric dilemma as prematurity is a major risk factor of neonatal death or a lifelong morbidity. Despite extensive efforts to reduce preterm birth, the means to identify and prevent it remains limited. Sonographic surveillance of CL can identify the increased risk of spontaneous preterm birth. Objective: To determine the predictive value of ultrasonographic assessment of the cervix after cerclage insertion for the outcome of preterm birth before 34 weeks of gestation. Patients and Methods: A prospective study included fifty women with singleton pregnancies were followed-up with monthly transvaginal ultrasonographic examinations before and after cerclage insertion. Ultrasonographic parameters of the cervix included the closed endocervical canal length and funneling depth measured from the internal cervical os. Results: The change in cervical length was predictive; as with stable cervical length an association with a later gestational age at delivery was evident. Patients with cerclage who delivered after 34 weeks had a slower rate of cervical shortening compared to those who delivered prior to that date (median = 4mm versus 7mm per 4 weeks). The overall cervical length at 28 weeks was statistically different between patients who delivered before 34 weeks and those who delivered later (24.00±2.92 versus 33.19±5.5 p<0.001). Conclusions: Transvaginal ultrasound for cervical assessment can be a helpful tool in the prediction of preterm birth after cerclage insertion. A late second-trimester cervical transvaginal ultrasound scan can guide the addition of interventions such, progesterone and antenatal corticosteroids for fetal lung maturation.