Risk factors for macrosomia in newborns at a school-maternity in northeast of Brazil

Abstract

Objective: to determine the frequency of macrosomia in babies born alive at a reference obstetric service, and its association with maternal risk factors. Methods: a transversal descriptive study, including 551 women at puerperium, hospitalized at Instituto de Saúde Elpídio de Almeida, in Campina Grande (PB), Brazil, from August to October, 2007. Women, whose deliveries had been assisted at the institution, with babies born alive from one single gestation and approached in the first postpartum day, were included in the study. The nutritional and sociodemographic maternal characteristics were analyzed, and the ratio of macrosomia (birth weight ≥4.000 g) and its association with maternal variables were determined. Macrosomia was classified as symmetric or asymmetric according to Rohrer's index. Statistical analysis has been done through Epi-Info 3.5 software; the prevalence ratio (PR) and the confidence interval at 95% (CI 95%) were calculated. The research protocol was approved by the local Ethics Committee and all the participants signed the informed consent. Results: the mean maternal age was 24.7 years old, and the mean gestational age was 38.6 weeks. Excessive gestational weight gain was observed in 21.3% of the pregnant women, and 2.1% of the participants had a diagnosis of diabetes mellitus (gestational or clinic). A ratio of 5.4% of macrosomic newborns was found, 60 were asymmetric. There was no significant association between macrosomia, mother's age and parity. There was an association between macrosomia and overweight/obesity in the pre-gestational period (PR=2.9; CI 95%=1.0-7.8) and at the last medical appointment (PR=4.9; CI 95%=1.9-12.5), excessive weight gain (PR = 6.9; CI 95%:2.8-16.9), clinical or gestational diabetes (PR = 8.9; CI 95%:4.1-19.4) and hypertension (PR=2.9; CI 95%=1.1-7.9). The factors that persisted significantly associated with macrosomia in the multivariate analysis were the excessive weight gain during the gestation (RR=6.9; CI 95%=2.9-16.9) and the presence of diabetes mellitus (RR=8.9, CI 95%=4.1-19.4). Conclusions: considering that excessive gestational weight gain and diabetes mellitus were the factors more strongly associated with macrosomia, it is important that precocious detection measurements and adequate follow-up of such conditions be taken, aiming at preventing unfavorable perinatal outcomes.