Risk factors for childbearing during adolescence in a population-based birth cohort in southern Brazil.

OBJECTIVE To use a case-control study to analyze risk factors associated with teenage childbearing among adolescents who were in a birth cohort study that began in 1982 in the city of Pelotas, Rio Grande do Sul, Brazil. METHODS Adolescent mothers in Pelotas who gave birth between January 1995 and March 2001 and who had been born in 1982 were identified through the local birth information system. These subjects from the 1982 birth cohort were compared to adolescents from the same cohort who had not given birth before March 2001. Standardized interviews were used in 2001 to obtain information about socioeconomic, maternal reproductive, demographic, and lifestyle characteristics. This information was combined with data obtained in earlier phases of this 1982 birth cohort study. Unconditional logistic regression was used to analyze the risk factors associated with childbearing during adolescence. RESULTS A total of 420 parous adolescents from the 1982 birth cohort were identified and then compared with 408 cohort adolescents who had not given birth by March 2001. Higher family income in 1982 and more parental schooling in 1982 were inversely related to childbearing among the birth cohort adolescents. Cohort girls whose mothers were under age 20 when they gave birth in 1982 had a higher risk of becoming pregnant while still an adolescent. Cohort girls who, during childhood, lived with siblings from different fathers were twice as likely to become an adolescent mother. Compared to cohort adolescents who had not failed during the first four years of school, those girls who had done so had twice the risk of giving birth during adolescence. Among the cohort girls a positive association was found between younger age at first intercourse and childbearing in adolescence. CONCLUSIONS The results indicate that the educational level of the adolescent mothers must be considered in planning policies that attempt to disrupt successive cycles of socioeconomic deprivation. Early interventions to improve sex education and to increase the motivation of young girls to achieve higher levels of education are needed. The interventions should aim for a reduction in the risk of long-term poverty and poorer educational achievements of teenage mothers and their children.