The association of gestational weight gain per institute of medicine guidelines and prepregnancy body mass index on outcomes of twin pregnancies.

OBJECTIVE: To determine if current recommendations for weight gain in twin pregnancies according to maternal prepregnancy body mass index (PPBMI) influence perinatal outcomes. METHODS: We identified women with twins enrolled in a maternity risk screening and education program with initial screening and prenatal care initiated at <20 weeks and delivery at >23.9 weeks. Women with normal, overweight, or obese PPBMI were included (n = 5129). Pregnancy outcomes were compared between those women with weight gain meeting or exceeding 2009 Institute of Medicine recommendations and patients who did not meet weight gain guidelines. RESULTS: Rates of spontaneous preterm delivery at <35 weeks were higher in all PPBMI groups for those with weight gain below guidelines. In all PPBMI groups, numbers of pregnancies with both infants weighing >2500 g or >1500 g were significantly higher for women gaining weight at or above guidelines. Logistic regression analysis was utilized to assess multivariate impact on outcome of spontaneous preterm delivery at <35 weeks showing that regardless of PPBMI level, women who gain below recommended guidelines are 50% more likely to deliver spontaneously at <35 weeks. CONCLUSION: In twin pregnancies, weight gain below recommended guidelines determined by maternal PPBMI is associated with higher rates of spontaneous preterm delivery at <35 weeks.

The influence of maternal age on pregnancy outcome in nulliparous women with twin gestation.

We sought to determine if outcomes of nulliparous twin pregnancies differ based on maternal age. Nulliparous women with current twin pregnancies were identified from a database of women enrolled for outpatient nursing surveillance. Data were stratified into four groups by maternal age: less than 20, 20 to 34, 35 to 39, and greater than or equal to 40 years. Maternal and neonatal outcomes for women less than 20, 35 to 39, and 40 or more were compared with 20- to 34-year-old controls using Kruskal-Wallis, Mann-Whitney, and Pearson chi-square analyses. We analyzed 2144 nulliparous twin pregnancies. Patients ≥35 years (34 to 39, 78.5% or ≥40, 85.9%) were more likely to have cesarean deliveries compared with controls 20 to 34 years old (71.2%). Women aged 35 to 39 were less likely to deliver at <37 weeks, and women in the ≥40 group were less likely to deliver at <35 weeks due to spontaneous preterm labor compared with the controls. Neonates born to women aged 35 to 39 had a greater gestational age at delivery and larger average birth weight than controls. Maternal and neonatal outcomes were not adversely influenced by advanced maternal age in nulliparous women carrying twin gestations.