Predictive value of transvaginal cervical length in triplet pregnancies for spontaneous preterm delivery at ≤ 32 weeks
Source: Journal of Maternal-Fetal and Neonatal Medicine, Volume 12, Number 1, 1 July 2002 , pp. 46-49(4)
Publisher: Informa Healthcare
Abstract:Objective: To establish whether cervical length is a predictor of spontaneous preterm delivery at ≤ 32 weeks in triplet pregnancies.
Methods: This was a case-control study of all triplet pregnancies followed with more than three sonographic assessments of cervical length at 4-week intervals from 1995 to 2000. Cervical length in women delivered spontaneously at ≤ 32 weeks (cases) was compared with that of the remaining women (controls). Statistical analysis included Fisher's exact test, 2 test, one-way analysis of variance, logistic regression and receiver operating characteristic (ROC) curve to determine optimal cervical length thresholds for spontaneous preterm delivery at ≤ 32 weeks.
Results: Of the 58 women included in the study, 17 (29%) delivered spontaneously at ≤ 32 weeks. The preterm delivery group had similar demographic and obstetric variables, but a higher rate of cerclage placement (65% vs 17%, p < 0.001) than controls. Mean ± standard deviation cervical length was significantly shorter among cases than controls at 16-20.0 weeks (3.0 ± 1.2 vs. 3.9 ± 0.8 cm, p = 0.01), but not at 20.1-24.0 weeks (3.5 ± 1.1 vs. 3.8 ± 1.0 cm, p = 0.76). Logistic regression analysis determined that cervical length at 16-20 weeks had an odds ratio of 0.43 (95% CI = 0.23, 0.80) for the prediction of spontaneous preterm delivery at ≤ 32 weeks. ROC curve analysis identified a cervical length of ≤ 2.6 cm as the optimal threshold for the prediction of spontaneous preterm delivery at ≤ 32 weeks (sensitivity 41%, specificity 92%).
Conclusions: In a population of triplet gestations with a 29% rate of preterm delivery, cervical length at 16-20.0 weeks, but not at 20.1-24.0 weeks, was inversely correlated with the probability of preterm delivery at ≤ 32 weeks.
Document Type: Original Article
Affiliations: 1: Department of Obstetrics and Gynecology, Georgetown University Hospital, Washington, District of Columbia, USA 2: Department of Obstetrics and Gynecology, Hackensack University Medical Center, Hackensack, New Jersey, USA 3: Department of Pharmacology and Biostatistics, Georgetown University Hospital, Washington, District of Columbia, USA
Publication date: July 1, 2002