Ultrasound monitoring of cervical length in twin Pregnancies

Preterm delivery is the major cause of adverse outcomes in twin pregnancy.  A shortened cervix at 20-24 weeks of amenorrhea is a good predictor of preterm birth in asymptomatic patients. However, there are no recommendations for serial cervical length measurements for these high risk pregnancies.

To evaluate the benefits from monthly cervical length monitoring in asymptomatic twin pregnancies.

This was a prospective study. We compared two groups of twin pregnancies (groupe 1: patients with a monthly and systematic transvaginal ultrasound measurement of the cervical length and groupe2 : patients without monitoring of cervical length) in terms of premature labor screening, mean gestational age at the diagnosis of preterm labor, time saved by tocolysis in case of preterm labor and  mean gestational age at delivery.

Ninety nine twin pregnancies were included: 35 patients had a systematic, monthly cervical length (group1) and 64 women had a traditional prenatal care without monitoring of cervical length (group2). A significant relationship between a cervical length measured between 22 and 24 weeks of amenorrhea inferior to 30 mm and preterm labor with a high specificity (100%) and a high positive predictive value (100%). The sensitivity remains average (45%).A significant benefit was demonstrated through this systematic ultrasound measurement of cervical length for the screening of preterm labor (p=0.018), the time saved by tocolysis (p=0.023), as well as the medium gestational age at birth (p=0.046).

Serial cervical length measurements seems to be a significant predictor of early preterm birth in asymptomatic twin pregnancies.