Transvaginal sonography of cervical length and Bishop score as predictors of successful induction of term labor: the effect of parity.
OBJECTIVE
To evaluate the predictive value for successful labor induction of transvaginal ultrasound (TVS) of cervical length according to parity.


METHODS
TVS of the cervix was performed before term labor induction. Induction was considered successful if vaginal delivery was achieved within 24 hours; 231 women were available for final analysis.


RESULTS
Analysis of the receiver operator characteristics curve showed an optimal cut-off for cervical length of < or = 20 mm for successful induction. Following multivariate logistic regression analysis, a sonographic short cervix (AOR 5.6; p < 0.001) was an independent predictor of successful induction but not a favorable Bishop score (p = 0.47). Among multiparas with a short cervix, positive and negative predictive values for successful induction were 98% (95% CI 90-100%) and 21% (95% CI 13%-32%) and among nulliparas, predictive values were 69% (95% CI 53%-82%) and 77% (95% CI 64%-87%) respectively.


CONCLUSIONS
In nulliparas, cervical length can usefully predict labor induction outcome.
Tan
P C
PC
Department of Obstetrics & Gynecology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia. pctan@um.edu.my
Vallikkannu
N
N
Suguna
S
S
Quek
K F
KF
Hassan
J
J
D000282:Administration, Intravaginal; D000328:Adult; D002584:Cervix Uteri / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D015331:Cohort Studies; D015232:Dinoprostone / Q000008:administration & dosage; D005260:Female; D006801:Humans; D007751:Labor, Induced; D010120:Oxytocics / Q000008:administration & dosage; D010298:Parity; D010808:Physical Examination; D011237:Predictive Value of Tests; D011247:Pregnancy; D011263:Pregnancy Trimester, Third; D012372:ROC Curve; D014463:Ultrasonography
D010120:Oxytocics; D015232:Dinoprostone