Can examination of the cervix provide useful information for prediction of cervical incompetence and following preterm labour?

Diagnosing cervical incompetence is difficult because there are no specific tests or criteria that confirm or exclude the diagnosis, and the accurate prediction and diagnosis of preterm labour continue to frustrate the clinician. To evaluate the condition of the cervical canal, when dilatation of the internal os is identifiable by digital examination, cervical ripening has advanced considerably. Measurement of cervical length by ultrasonography offers the possibility of confirming cervical canal shortening before it is evident by digital examination. Transabdominal observations require a full urinary bladder, and the uterus is consequently deformed from the lower part to the fetal head. Measurement of cervical length by transvaginal ultrasonography has made it possible to resolve the problems associated with transabdominal observation and to assess the condition of the cervical canal in more detail. Application of transfundal pressure during transvaginal ultrasound evaluation of the cervix and its internal os may assist in detecting the asymptomatic incompetent cervix.