Prematurity in a Sample of Brazilian Twins: A Cross-Sectional Study

Objective: To evaluate the characteristics of newborns of pregnant women attending a public maternity hospital in Rio de Janeiro, Brazil. Methods: A retrospective cross-sectional study of records of newborn twins from adult and adolescent pregnancies. Twins were divided into two groups, Twin 1, the first one delivered, and Twin 2, the second. The association between gestational age at birth and neonatal characteristics were analysed using Chi Square and Fisher’s exact tests and associations were considered significant when p-values were ≤ 0.05. Results: We evaluated 218 infants with a mean gestational age of 35.7 weeks at birth. The groups twin 1 and 2 showed, respectively, average weight at birth of 2343.9 grams (SD = 627.3) and 2267.6 grams (SD = 608.2). Most twins of group 1 presented appropriate birth weight (n = 53; 48.6%) and were classified as appropriate for gestational age (n = 88; 80.7%). The group twin 2 had, mostly, low birth weight (n = 55; 50.5%), and were classified as appropriate for gestational age (n = 93; 85.3%). Prematurity was relevant to the development of postnatal complications (twin 1 - p = 0.002; twin 2 - p = 0.001) and low birth weight (twins 1 - p = 0.000; twins 2 - p = 0.000) for both groups. Conclusion: Prematurity was an important risk factor for the development of postnatal metabolic and respiratory complications and low birth weight for both groups. Keywords: Twin pregnancy; Nutritional Epidemiology; Prenatal care; prenatal nutrition; Prematurit