The Efficacy of Sonographically Indicated Cerclage in Multiple Gestations

Objective The purpose of this study was to determine the efficacy of sonographically indicated cerclage in multiple gestations with sonographic evidence of short cervical length (CL). Methods Between 1996 and 2002, all multiple gestations undergoing serial CL determinations in the second trimester were identified in 2 separate institutions. Cervical lengths were measured sonographically with transvaginal probes (4–8 MHz). Short CL was defined as a closed CL of 2.5 cm or less. When a short CL was identified before 24 weeks, the study group underwent sonographically indicated cerclage via the modified Shirodkar technique; control patients were placed on bed rest without surgical intervention. The primary outcome was incidence of spontaneous preterm birth before 32 weeks. The groups were compared with the Mann‐Whitney U test and the Fisher exact test, with a 2‐sided P < .05 used to define statistical significance. Odds ratios were calculated, and 95% confidence intervals were reported. Results A total of 414 sets of twin gestations and 92 sets of triplet gestations were identified. The median gestational age at delivery for twin gestations was 34.0 weeks for patients who received cervical cerclage and 34.4 weeks for patients with short cervix and no cerclage (P = .77). The median gestational age at delivery for triplet gestations was 34.1 weeks for patients who received cervical cerclage and 33.0 weeks for patients with short cervix and no cerclage (P = .21). There was no difference in the rate of spontaneous preterm delivery at fewer than 28, 30, 32, and 34 weeks or in the rate of preterm premature ruptured membranes. Conclusions In our study of multiple gestations with short CL, sonographically indicated cerclage was not associated with a lower incidence of spontaneous preterm delivery compared with conservative management

"Blind" vaginal fetal fibronectin as a predictor of spontaneous preterm delivery

To assess the accuracy of vaginal fetal fibronectin sampling without use of a sterile speculum examination as a screening test for predicting spontaneous preterm birth. A historical cohort of patients who were followed up with serial fetal fibronectin testing between 1998 and 2001 was identified. All patients were considered to be at high risk for preterm delivery and were screened with fetal fibronectin testing without using a speculum at 2- to 3-week intervals from 22 weeks to 32 weeks of gestation. Charts were reviewed for fetal fibronectin results and pregnancy outcome data. Groups were compared using chi(2) analysis or Fisher exact test with significance defined as P < .05. A total of 1,396 fetal fibronectin tests from 416 pregnancies were performed via the "blind" sampling technique. Overall, 24.9% of pregnancies delivered spontaneously before 37 weeks; 9.1% delivered spontaneously before 34 weeks. For delivery before 34 weeks of gestation, the test had a sensitivity of 44.7%, a specificity of 88.4%, a positive predictive value of 27.9%, and a negative predictive value of 94.1%. For delivery within 14 and 21 days of a single fetal fibronectin assessment, the test had a sensitivity of 52% and 45.5%, a specificity of 94.5% and 94.9%, a positive predictive value of 14.6% and 22.5%, and a negative predictive value of 99.1% and 98.2%, respectively. "Blind" vaginal fetal fibronectin sampling has high negative predictive values and specificities in predicting spontaneous preterm birth. II-2