Is adolescent pregnancy a risk factor for low birth weight?

OBJECTIVE The objective of this study was to evaluate whether adolescent pregnancy is a risk factor for low birth weight (LBW) babies. METHODS This was a cross-sectional study of mothers and their newborns from a birth cohort in Aracaju, Northeastern Brazil. Data were collected consecutively from March to July 2005. Information collected included socioeconomic, biological and reproductive aspects of the mothers, using a standardized questionnaire. The impact of early pregnancy on birth weight was evaluated by multiple logistic regression. RESULTS We studied 4,746 pairs of mothers and their babies. Of these, 20.6% were adolescents (< 20 years of age). Adolescent mothers had worse socioeconomic and reproductive conditions and perinatal outcomes when compared to other age groups. Having no prenatal care and smoking during pregnancy were the risk factors associated with low birth weight. Adolescent pregnancy, when linked to marital status "without partner", was associated with an increased proportion of low birth weight babies. CONCLUSIONS Adolescence was a risk factor for LBW only for mothers without partners. Smoking during pregnancy and lack of prenatal care were considered to be independent risk factors for LBW.