[Birth weight and factors associated with the prenatal period: a cross-sectional study in a maternity hospital of reference].

This study examined factors related to birth weight in a maternity hospital in the city of Rio de Janeiro. It is a descriptive, sectional study conducted in the Herculano Pinheiro Maternity Hospital (HMHP) in Rio de Janeiro between December 2008 and February 2009, with postpartum mothers between 20 and 34 years of age. The chi-square test, the Student's t test and the logistical regression model were applied. 14.6% of the infants had low birth weight (less than 2500 g). There was a negative correlation between birth weight and smoking habits of the mother. The pre-pregnancy weight, maternal pre-pregnancy body mass index and number of pre-natal visit variables were positively associated with birth weight. Multiple regression analysis indicated maternal age as being a risk factor for low birth weight. The conclusion reached is that the marital status situation, where this was perceived as an important variable, as well as the number of prenatal visits, which in group analysis showed no statistical significance, deserve further investigation together with other studies.