Ultrasonic assessment of cervical dynamics at term of pregnancy

Background. To assess if ultrasonic measurement of the cervical canal has carries, at term of pregnancy, a relationship with the onset of labour. To assess if cervical length identifies women at risk to deliver beyond 42 completed weeks of gestation (287 days). Methods. Prospective case-control study, carried out between 37 and 40 weeks of gestation in uncomplicated, singleton, cephalic presentation, pregnant women. Setting: outpatient ultrasound Department of a tertiary referral centre, serving >1000 pregnancies. Weekly measurements of the cervical canal by transvaginal ultrasound probe. Results. Inverse relationship between sonographic measurements and advancing gestational age. At 38 weeks of gestation, significant difference in the ultrasonic recordings between patients delivered before and beyond 41 completed weeks. Conclusions. It is possible to identify as early as 38 weeks of gestation those women that will deliver beyond 41 weeks. There is a subgroup of nulliparous patients that will probabily be candidates to induction of labour.