Twin pregnancy and perinatal outcomes: Data from 'Birth in Brazil Study'.

BACKGROUND: Twin pregnancies account for 0.5-2.0% of all gestations worldwide. They have a negative impact on perinatal health indicators, mainly owing to the increased risk for preterm birth. However, population-based data from low/middle income countries are limited. The current paper aims to understand the health risks of twins, compared to singletons, amongst late preterms and early terms. METHODS: Data is from "Birth in Brazil", a national inquiry into childbirth care conducted in 2011/2012 in 266 maternity hospitals. We included women with a live birth or a stillborn, and excluded births of triplets or more, totalling 23,746 singletons and 554 twins. We used multiple logistic regressions and adjusted for potential confounders. RESULTS: Twins accounted for 1.2% of gestations and 2.3% of newborns. They had higher prevalence of low birth weight and intrauterine growth restriction, when compared to singletons, in all gestational age groups, except in the very premature ones (<34 weeks). Amongst late preterm's, twins had higher odds of jaundice (OR 2.7, 95% CI 1.8-4.2) and antibiotic use (OR 1.8, 95% CI 1.1-3.2). Amongst early-terms, twins had higher odds of oxygen therapy (OR 2.7, 95% CI 1.3-5.9), admission to neonatal intensive care unit (OR 3.1, 95% CI 1.5-6.5), transient tachypnoea (OR 3.7, 95% CI 1.5-9.2), jaundice (OR 2.8, 95% CI 1.3-5.9) and antibiotic use (OR 2.2, 95% CI 1.14.9). In relation to birth order, the second-born infant had an elevated likelihood of jaundice, antibiotic use and oxygen therapy, than the first-born infant. CONCLUSION: Although strongly mediated by gestational age, an independent risk remains for twins for most neonatal morbidities, when compared to singletons. These disadvantages seem to be more prominent in early-term newborns than in the late preterm ones.

Gestational weight gain and adverse maternal outcomes in Brazilian women according to body mass index categories: An analysis of data from the Birth in Brazil survey.

BACKGROUND & AIMS: Monitoring gestational weight gain (GWG) is relevant for perinatal outcomes, especially in the context of increasing obesity and overweight in the female population. This study analyses the association between GWG in Brazilian women, according to different body mass index (BMI) categories, and different outcomes, including hypertensive disorders of pregnancy (HDP), gestational diabetes (GD) and caesarean section. METHODS: Data on women from all the major regions of Brazil with a single pregnancy of a gestational age of 28 weeks or more and information available for anthropometric evaluation were included in the Birth in Brazil survey. Adequacy of GWG was assessed according to the percentile distribution of GWG of women with favourable neonatal outcomes, with the median of the distribution referred to as 100% adequacy in the GWG evaluation. RESULTS: The study consisted of 18,953 women, 58.3% of whom were normal weight and 35.1% were overweight. The adequacy of GWG was better amongst the normal weight women (91.1%) and worse amongst those with class III obesity (46.0% with excessive GWG), with the latter showing the highest occurrence of adverse outcomes. Results of the multivariate logistic regression analysis revealed that weight gain above 200% of the median in the normal weight, overweight and obese women was positively associated with HDP and caesarean section, but not with GD. CONCLUSIONS: The proposed ranges of appropriate GWG associated with favourable neonatal outcomes based on the data from the Birth in Brazil survey proved good predictors of HDP and caesarean section amongst the women included in the study.