Objective To investigate the validity of a prediction model for success of vaginal birth after cesarean delivery (VBAC) in an ethnically diverse population. Methods We performed a retrospective cohort study of women admitted at a single academic institution for a trial of labor after cesarean from May 2007 to January 2015. Individual predicted success rates were calculated using the Maternal–Fetal Medicine Units Network prediction model. Participants were stratified into three probability-of-success groups: low (<35%), moderate (35–65%), and high (>65%). The actual versus predicted success rates were compared. Results In total, 568 women met inclusion criteria. Successful VBAC occurred in 402 (71%), compared with a predicted success rate of 66% (p = 0.016). Actual VBAC success rates were higher than predicted by the model in the low (57 vs. 29%; p < 0.001) and moderate (61 vs. 52%; p = 0.003) groups. In the high probability group, the observed and predicted VBAC rates were the same (79%). Conclusion When the predicted success rate was above 65%, the model was highly accurate. In contrast, for women with predicted success rates <35%, actual VBAC rates were nearly twofold higher in our population, suggesting that they should not be discouraged by a low prediction score.

Key Points Question Are prenatal ultrasonographic findings in maternal Zika virus infection associated with adverse neonatal outcomes? Findings In this cohort study of 92 women with confirmed Zika virus infection in pregnancy, 37 had an abnormal result on prenatal ultrasonography that was associated with adverse composite neonatal outcomes. However, 23 of 55 neonates who had normal results on prenatal ultrasonography still had adverse neonatal outcomes. Meaning Abnormal results on prenatal ultrasonography are associated with adverse neonatal outcomes; however, a comprehensive neonatal evaluation is recommended for all infants with suspected in utero Zika exposure.

Cerclage in twin pregnancies significantly decreased the rate of spontaneous preterm birth <32 weeks compared to expectant management. However, when stratified by cerclage indication, this decrease in primary outcome only remained significant in the group with cervical dilation.

There is limited data on amniocentesis as a diagnostic tool for congenital Zika syndrome. Here we report on a prospective cohort of 16 women with suspected Zika virus infection in a highly endemic area, and discusss the role of amniocentesis in the prenatal diagnosis of fetal Zika infection.