Faculty Bibliography

OBJECTIVE: The purpose of this study was to determine if prophylactic cerclage improves pregnancy outcome in women with triplet pregnancies without a history of cervical insufficiency. STUDY DESIGN: Triplet pregnancies with > or = 1 day of outpatient surveillance beginning before 32 weeks' gestation were identified from a database of women in the US who received outpatient preterm labor surveillance services between January 1990 and May 2004. Triplet pregnancies managed with prophylactic cerclage were compared with triplet pregnancies in which cerclage was not placed. Patients with a diagnosis of cervical insufficiency in a previous or in the index pregnancy were excluded from analysis. The primary outcome was incidence of preterm birth before 32 weeks. Groups were compared using Fisher exact test, and Student t test with 2-sided P values < .05 considered statistically significant. RESULTS: Three thousand two hundred seventy-eight triplet pregnancies met criteria for inclusion, of which 248 women (7.6%) received prophylactic cerclage. No significant differences were seen in mean gestational age at delivery, incidence of preterm birth before 32 weeks, birth weight, or neonatal days in the hospital. This study had 80% power to detect a 30% reduction in the primary outcome. CONCLUSION: Prophylactic cerclage did not result in improved pregnancy or neonatal outcomes in triplet pregnancies without a history of cervical insufficiency

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

Ultrasound has an important role not only in assessing amnionicity and chorionicity but also in diagnosing abnormalities and providing fetal surveillance throughout the duration of gestation

OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 'Blind' vaginal fetal fibronectin sampling has high negative predictive values and specificities in predicting spontaneous preterm birth. LEVEL OF EVIDENCE: II-2

OBJECTIVE: While an echogenic intracardiac focus (EIF) is associated with an increased risk of trisomy 21 (T21), the magnitude of that risk remains controversial, particularly in the setting of a low-risk triple screen (TS). The objective of this study is to define the risk of T21 in patients with a low-risk TS and an isolated EIF. STUDY DESIGN: A retrospective analysis was performed on patients presenting prior to 22 6/7 weeks of gestation. Patients met criteria for inclusion if an EIF was noted, a TS had been drawn, the anatomic survey was complete and was determined to be normal, and karyotyping or delivery occurred at Bellevue Hospital. A high-risk TS was defined as a risk of <1:500, assuming a 2-fold increased risk in the setting of an isolated EIF. A low-risk TS was defined as a risk of >1:500. Statistical analysis was performed using chi-square, with p values of <0.05 considered significant. RESULTS: 7,318 anatomic surveys were performed. An EIF was identified in 584 patients (7.98%), of which 391 met the criteria for inclusion. Of the 391, 51% were Asian and 38% were Hispanic; 348 had a low-risk TS and 43 had a high-risk TS. Patients with an EIF and a low-risk TS had a significantly lower risk of having a T21 pregnancy compared to those with a high-risk TS and an EIF (0 vs. 2.3%; p = 0.004). CONCLUSION: An isolated EIF with a low risk TS is not associated with an increased risk of T21

OBJECTIVE: To review our experience with a minimally invasive technique for umbilical cord occlusion as a method of selective feticide in monochorionic sets. STUDY DESIGN: Umbilical cord occlusion was completed using 3 mm bipolar cautery under ultrasound guidance (3D/4D, n = 6; 2D, n = 6) with pre and post ligation endoscopic evaluation. RESULTS: 12 cases of monochorionic sets where selective feticide was performed were identified during the period 2000 to present. There were four triplet and eight twin gestations in the study cohort. Median interval from intervention to delivery was 16 weeks (range, 5-19). All co-twins survived the procedure and 15 of 16 were delivered after 33 weeks. CONCLUSIONS: Umbilical cord occlusion in monochorionic sets can be accomplished in a minimally invasive manner with combined endoscopic and ultrasound guidance in both twin and triplet pregnancies