The objective of this work is to identify the causes and consequences of motherhood for the Brazilian adolescent mothers aged 15-19. Taking into account the differences in their reproductive behavior, they were split into two groups of age: 15-17 and 18-19 years old. In order to achieve the purpose of this research, some aspects of their living conditions, such as household income, schooling, occupational status position, family position and number of children have been analyzed. The data on living conditions of adolescent mothers has been compared with the data on female adolescents who have never had children. The change in their living conditions from Cardoso's neoliberal government to Lula's social-democratic government has been compared as well. The research findings indicate that motherhood in adolescence prevail among the poorest. They indicate as well that even before pregnancy most of them were not enrolled at school and as a consequence were not likely to get a decent job.