Purpose: to investigate factors accountable for macrosomia incidence in a study with mothers and progeny attended at a Basic Unity of Health in Rio de Janeiro, Brazil.
Methods: a prospective study, with 195 pairs of mothers and progeny, in which the dependent variable was macrosomia (weight at delivery > or =4,000 g -- independent of the gestational age or of other demographic variables), and socioeconomic, previous pregnancies/gestation course, biochemical, behavioral and anthropometric, the independent variables. Statistical analysis has been done by multiple logistic regression. Relative risk (RR) values have been estimated, based on the simple form: RR=OR/ (1 - I0) + (I0 versus OR), in which I0 is the macrosomia incidence in non-exposed people.
Results: Macrosomia incidence was 6.7%, the highest value being found in the progeny of women > or =30 years old (12.8%), white (10.4%), with two or more children (16.7%), with male newborns (9.6%), with height > or =1.6 m (12.5%), with overweight or obesity as a nutritional pre-gestational state (13.6%), and with excessive gestational gain of weight (12.7%). The final model has shown that having two or more children (RR=3.7; CI95%=1.1-9.9), and having a male newborn (RR=7.5; CI95%=1.0-37.6) were the variables linked to the macrosomia occurrence.
Conclusions: macrosomia incidence was higher than the one observed in Brazil as a whole, but inferior to the one reported in studies from developed countries. Having two or more children and a newborn male were the factors accountable for the occurrence of macrosomia.