The association between maternal weight gain and spontaneous preterm birth in twin pregnancies.

OBJECTIVE: To estimate the association between maternal weight gain and SPTB in twin pregnancies. METHODS: A case-control study of patients with twin pregnancies and a normal prepregnancy BMI (18.5-24.9 kg/m(2)) in one maternal-fetal medicine practice from 2005 to 2013. We reviewed maternal weight in six time periods: prepregnancy, 12-15 6/7 weeks, 16-19 6/7 weeks, 20-23 6/7 weeks, 24-27 6/7 weeks and 28-31 6/7 weeks. We compared maternal weight gain patterns across pregnancy between patients who did and did not have SPTB <32 weeks. Student's t-test and chi-square were used for analysis. RESULTS: In total, 382 patients were included, 29 (7.6%) of whom had SPTB <32 weeks. The baseline height, weight and BMI did not differ between the groups, nor did maternal age, IVF status, race or chorionicity. Patients with SPTB <32 weeks had significantly less weight gain as early as 15 6/7 weeks (2.9 ± 4.6 versus 7.3 ± 6.6 lb, p < 0.001), and this continued until 31 6/7 weeks (25.3 ± 8.7 versus 30.8 ± 10.9 lb, p = 0.037). CONCLUSIONS: In twin pregnancies with a normal prepregnancy BMI, there is a significant association between SPTB <32 weeks and lower maternal weight gain, particularly prior to 16 weeks. Future studies are needed to test if prepregnancy or early nutritional interventions in twin pregnancies can reduce the risk of preterm birth and improve neonatal outcomes in this high-risk population.

Type of congenital uterine anomaly and adverse pregnancy outcomes.

OBJECTIVE: To estimate whether the severity of uterine anomaly is associated with the risk of adverse pregnancy outcomes. METHODS: Retrospective cohort study of patients delivered by one maternal fetal medicine group from 2005 to 2012. We included 158 patients with a singleton pregnancy and a uterine anomaly, as well as an equal number of randomly selected unexposed singleton pregnancies delivered by the same group. Patients with uterine anomalies were subdivided into those with major fusion defects (unicornuate, bicornuate and didelphys) and minor fusion defects (arcuate, septate and t-shaped). RESULTS: The incidence of adverse pregnancy outcomes increased across unexposed patients, patients with minor fusion defects and patients with major fusion defects. These included preterm birth < 37 weeks, preterm birth < 35 weeks, birth weight < 10th percentile, birth weight < 5th percentile, preeclampsia, malpresentation and cesarean delivery. CONCLUSION: The incidence of adverse pregnancy outcomes and cesarean delivery is increased in patients with minor fusion defects and is further increased in patients with major fusion defects.