Maternal characteristics and neonatal outcomes in twin pregnancies in Brazil: A nationwide population-based study,...

To describe maternal characteristics and neonatal outcomes of twin pregnancies in Brazil, nationwide and across macro-regions, between 2015 and 2024.

This descriptive study used data from the Brazilian Live Birth Information System (SINASC). All live births from twin pregnancies with gestational age ≥ 24 weeks, maternal age 19-49 years, and complete information on birth weight and gestational age were included. Deterministic record linkage was applied to identify complete twin pairs. Maternal characteristics included age, education, prenatal care utilization, marital status, race/skin color, region of residence, and mode of delivery. Neonatal outcomes included low birth weight (<2,500 g), preterm birth (<37 weeks), and birth weight discordance (≥ 20%). Frequencies and corresponding 95% confidence intervals were estimated by year and macro-region.

A total of 437,728 live births (218,864 complete twin pairs) were included. Most mothers were aged 25-34 years (53.1%), had 8-11 years of schooling (56.0%), attended seven or more prenatal visits (75.3%), and had a cesarean delivery (87.5%). Higher concentrations of twin births were observed in the Southeast and Northeast regions. Approximately 60% of newborns had low birth weight and were born preterm, and these outcomes were more frequent in the South and Southeast regions. Birth weight discordance ≥ 20% occurred in approximately 16% of twin pairs and showed limited regional variation.

Twin pregnancies in Brazil present a substantial burden of adverse neonatal outcomes and marked regional inequalities. Strengthening specialized prenatal and perinatal care and adopting twin-specific clinical and epidemiological criteria are essential to improve risk assessment and optimize care for this high-risk population.