A predictive model of short cervix at 20-24 weeks using first-trimester cervical length measurement and maternal history.
OBJECTIVE
To develop a model for the prediction of short cervix ( ≤ 15 mm) at 20-24 weeks by combining maternal history and transvaginal ultrasonographic measurement of cervical length at 11-14 weeks. To explore the value of an additional ultrasound examination of the cervix at about 17 weeks.


METHODS
Longitudinal prospective study in 800 unselected pregnant women presenting for first-trimester ultrasound assessment by nuchal translucency and serum biochemistry. Cervical length was evaluated transvaginally between 11 weeks and 13 weeks and 6 days (cx1), at 16-19 weeks (cx2) and 20-24 weeks (cx3). Backward multiple logistic regression analysis with cx3 ≤ 15 mm as the dependent variable was used to identify the predictors of a short cervix at 20-24 weeks.


RESULTS
Cx1 and history of preterm delivery were significant independent contributors of a short cervix at 20-24 weeks [area under the curve (AUC 0.808, p < 0.001, Model) 1]. Furthermore, the cx1/cx2 ratio was a significant independent predictor of a short cervix at 20-24 weeks (odds ratio = 58.325 p = 0.012). The addition of the cx1/cx2 ratio improved the model (AUC = 0.878, p < 0.001, Model 2).


CONCLUSIONS
A short cervix at 20-24 weeks can be predicted at the 11-14 weeks scan. The addition of a cervical measurement at about 17 weeks can improve the prediction model.
Fetal Medicine Unit, 3rd Department of Obstetrics and Gynaecology, University of Athens, Attikon University Hospital, Athens, Greece. athena.souka@googlemail.com
A P
AP
Souka
I
I
Papastefanou
V
V
Michalitsi
G K
GK
Papadopoulos
D
D
Kassanos
D000293:Adolescent; D000328:Adult; D054791:Cervical Length Measurement; D002584:Cervix Uteri / Q000000981:diagnostic imaging*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008875:Middle Aged; D008954:Models, Biological; D011247:Pregnancy; D011248:Pregnancy Complications / Q000000981:diagnostic imaging*; D011261:Pregnancy Trimester, First; D011446:Prospective Studies; D002577:Uterine Cervical Diseases / Q000000981:diagnostic imaging*; D055815:Young Adult