Faculty Bibliography

Abstract Objective: To compare pregnancy outcomes in twin pregnancies based on maternal pre-pregnancy body mass index (BMI). Methods: Historical cohort study of all twin pregnancies >24 weeks managed by one maternal-fetal medicine practice from 2005 to 2012. We compared pregnancy outcomes between pre-pregnancy obese (BMI >/=30 kg/m(2)) and normal weight women (BMI 18.5-24.99 kg/m(2)). We also compared pre-pregnancy normal weight women to overweight women (BMI 25-29.99 kg/m(2)) and underweight women (BMI <18.5 kg/m(2)). Chi square, Fisher's exact test, Student's t-test, and one-way ANOVA were used as appropriate. A p value of <0.05 was considered significant. Results: Five hundred fourteen patients with twin pregnancies were included. Pre-pregnancy obesity was associated with gestational hypertension (34.1% versus 17.9%, p = 0.011), preeclampsia (27.3% versus 14.4%, p = 0.028), and gestational diabetes (22.2% versus 4.7%, p < 0.001). Pre-pregnancy overweight was associated with gestational diabetes (13.7% versus 4.7%, p = 0.002). Pre-pregnancy underweight was not associated with any adverse pregnancy outcomes. Comparing outcomes across normal weight, overweight, and obese women, the rates of gestational diabetes and gestational hypertension increased significantly across the three groups. Conclusion: In patients with twin pregnancy, pre-pregnancy obesity is associated with adverse pregnancy outcomes, including gestational diabetes, gestational hypertension, and preeclampsia.

Objectives- The purpose of this study was to estimate the prevalence and persistence rate of vasa previa in at-risk pregnancies using a standardized screening protocol. Methods- We conducted a descriptive study of patients with a diagnosis of vasa previa from a single ultrasound unit between June 2005 and June 2012. Vasa previa was defined as a fetal vessel within 2 cm of the internal cervical os on transvaginal sonography. Screening for vasa previa using transvaginal sonography with color flow mapping was performed routinely in the following situations: resolved placenta previa, prior pregnancy with vasa previa, velamentous insertion of the cord in the lower uterine segment, placenta succenturiata in the lower uterine segment, and twin gestations. Results- A total of 27,573 patients were referred to our unit for fetal anatomic surveys over the study period. Thirty-one cases of vasa previa were identified, for an incidence of 1.1 per 1000 pregnancies. Twenty-nine cases had full records available for analysis. Five patients (17.2%) had migration and resolution of the vasa previa. When the diagnosis was made during the second trimester (<26 weeks), there was a 23.8% resolution rate (5 of 21); when the diagnosis was made in the third trimester, none resolved (0 of 8 cases). Of the 24 pregnancies (5 twin gestations and 19 singleton gestations) with persistent vasa previa, there was 100% perinatal survival and a median length of gestation of 35 weeks (range, 27 weeks 5 days-36 weeks 5 days). No known missed cases were identified over the study period. Conclusions- The use of standardized screening for vasa previa based on focused criteria was found to be effective in diagnosing vasa previa, with a 100% survival rate. Vasa previa diagnosed during the second trimester resolves in approximately 25% of cases.