[Teenage pregnancy and factors associated with low birth weight].

PURPOSE to analyze the association of pregnancy in adolescence with low birth weight (LBW). METHODS all the patients who gave birth in a teaching Hospital at Maranhão State from July to December 2006 were included in the study and were split in two groups: adolescents (ten to 19 years old) and adults (20 to 34 years old). The variables studied were: skin color, schooling, marital status, family income, number of pre-natal appointments, gestational age at the onset of pre-natal assistance, place where they spend that period, gestation duration, delivery route and birth weight. Data were processed by the Epi-Info program, 3.4.1 version, and the associations between variables were analyzed by the Odds Ratio (OR), with a confidence interval (CI) of 95%. Models of logistic regression were also used. The significance level adopted was 0.05. RESULTS 1,978 patients were evaluated. A ratio of 25.4% of deliveries in adolescents was observed; they presented low level of schooling, no mates, low number of pre-natal appointments, late onset of pre-natal assistance, low birth weight and prematurity. In the analysis of LBW as end variable, associated to prematurity (OR=29.0), it was clear the association with low number of pre-natal appointments (OR=2.98; 95%CI=2.23-4.00), pre-natal late onset (OR=1.91; 95%CI=1.3-2.6) and low schooling (OR=1.95; 95%CI=1.4-2.5) related to adolescence (OR=1.50; 95%CI=1.1-1.9). Similar results were obtained when the prematurity variable was excluded. Adolescents showed lower incidence of caesarean section (33.3%) than adults (49.4%), a significant difference, besides lower association with pre-eclampsia and cephalo-pelvic disproportion. CONCLUSIONS pregnancy in adolescence was associated to pre-natal late onset and low number of appointments, besides low schooling, low birth weight and a lower incidence of cephalo pelvic disproportion and pre-eclampsia.