Cervical incompetence: the use of transvaginal sonography to provide an objective diagnosis.
OBJECTIVE
To investigate the use of transvaginal sonography in monitoring the cervix in women at high risk of a preterm delivery.


METHODS
One hundred and six women at high risk of preterm labor had regular cervical monitoring by transvaginal ultrasound throughout pregnancy from the second trimester to delivery. The study was designed to be observational, but intervention was considered if the cervical length fell below 10 mm.


RESULTS
Eleven women demonstrated opening of the cervical canal at rest or with fundal pressure before 24 weeks' gestation. Between 2 and 17 days later all 11 cervices progressively shortened to a cervical length of < 10 mm. Nine women had a cervical cerclage. Seven women had fetal membranes visible within the cervical canal at the time of cerclage. One woman miscarried at 18 weeks, and the other 10 had live births at a median gestational age of 36 (range, 27-38) weeks.


CONCLUSIONS
Cervical length shortening in the second trimester, once started, progressed to a cervical length under 10 mm. Opening of the cervical os at rest or in response to fundal pressure detected by transvaginal ultrasound appears to be the early ultrasound feature of cervical incompetence.
Macdonald
R
R
Bath Royal United Hospital, Bath and Southmead Hospital, Bristol, UK.
Smith
P
P
Vyas
S
S
D002584:Cervix Uteri / Q000000981:diagnostic imaging* / Q000601:surgery; D005260:Female; D006801:Humans; D007752:Obstetric Labor, Premature / Q000000981:diagnostic imaging; D011237:Predictive Value of Tests; D011247:Pregnancy; D018566:Pregnancy, High-Risk; D012307:Risk Factors; D012680:Sensitivity and Specificity; D014463:Ultrasonography; D002581:Uterine Cervical Incompetence / Q000000981:diagnostic imaging* / Q000601:surgery