SUMMARY OBJECTIVE: This study aimed to evaluate the frequency of late pregnancies in Brazil, the age-specific fertility rate (ASFR) in the regions, the rate of prematurity, and the rate of low birth weight (LBW) and their association with advanced maternal age compared with 20–34-year-old women. METHODS: This was a cross-sectional study conducted by searching the Information System on Live Births (Sistema de Informações Sobre Nascidos Vivos [SINASC]). Data from 1995 to 2018 were collected, and pregnant women were divided into three categories based on their age range: 35–39, 40–44, and ≥45 years. The study calculated the frequency of deliveries of mothers of advanced age in Brazil, the ASFR, and the rates of prematurity and LBW in each group. RESULTS: The frequency of newborns (NB) of mothers aged ≥35 years increased by 64%. The 35–39-year-old ASFR increased in all regions, except in the northeast. At maternal age ≥35 years, NB increased by 58% between 28 and 36 weeks during the study period. LBW increased between 500 and 1,499 g in 68.7% and between 1,500 and 2499 g in 57% of cases. In 2018, regarding the age range of 20–34 years, the chance of premature delivery was 29% at 35–39 years (OR=1.29), 54% higher at 40–44 years (OR=1.54), and 114% higher at ≥45 years (OR=2.14); while the chance of LBW increased by 28% at 35–39 years (OR=1.28), 56% at 40–44 years (OR=1.56), and 139% at 45 years or older (OR=2.39). CONCLUSIONS: The frequency of deliveries and ASFR ≥35 years increased between 1995 and 2018. The chances of prematurity and LBW were higher with increased maternal age.

RESUMO INTRODUÇÃO A gravidez na adolescência é fenômeno universal, com maior prevalência nos países em desenvolvimento. Embora venha apresentando redução desde 2000 no Brasil, a taxa de fecundidade específica para essa faixa etária permanece elevada. OBJETIVO Avaliar a frequência da gravidez na adolescência no Brasil, no período de 2006 a 2015, e a associação com o Índice de Desenvolvimento Humano (IDH). MÉTODO Estudo epidemiológico, descritivo, realizado por busca no banco de dados no Departamento de Informática do Sistema Único de Saúde (Datasus), utilizando informações do Sistema de Informação sobre Nascidos Vivos (Sinasc) sobre as cinco regiões brasileiras. RESULTADOS Ocorreu queda do percentual de nascidos vivos (NV) de mães adolescentes (10 a 19 anos) no Brasil de 13,5% nos últimos dez anos. Essa redução foi notada em todas as regiões brasileiras, entre mães de 15 e 19 anos. O número de NV aumentou 5,0% entre aquelas de 10 a 14 anos na Região Norte e foi reduzido nas demais regiões, sendo maior no Sul (18,0%). A taxa de fecundidade específica de 15-19 anos diminiu de 70,9/1.000 para 61,8/1.000 no período. A proporção de NV se associa inversamente ao IDH, exceto no Nordeste, onde ocorreu importante redução (18,0%) entre as mães de 15-19 anos e de 2% entre 10-14 anos. CONCLUSÃO A gravidez na adolescência no Brasil encontra-se em lento declínio, especialmente entre 10-14 anos, e está inversamente associada ao IDH, exceto no Nordeste.

SUMMARY INTRODUCTION Teenage pregnancy is a universal phenomenon, with higher prevalence in developing countries. Although there has been a reduction in Brasil since the year 2000, the age-specific fertility rate for this age group remains high. OBJECTIVE To evaluate the frequency of adolescence pregnancy in in Brasil from 2006 to 2015 and its association with the Human Development Index (HDI). METHODS A descriptive epidemiological study, conducted by searching the database of the Department of Informatics of the Unified Health System (DATASUS), using information from the Information System on Live Births (SINASC) for the five Brazilian regions. RESULTS There was a reduction in the percentage of live births (LB) from adolescent mothers (10 to 19 years old) in Brasil by 13.0% over the last ten years. This decline was observed in all Brazilian regions among mothers aged 15 to 19 years. The number of LB increased by 5.0% among mothers aged 10 to 14 years in the North and decreased in the other regions, with higher rates in the South (18.0%). The specific fertility rate for the 15-19-year-old group decreased from 70.9/1,000 to 61.8/1,000 in the period. The proportion of LB is inversely associated with the HDI, except in the Northeast (the lowest HDI in the country), where there was a significant reduction (18.0%) among mothers aged 15-19 and 2% among those aged 10-14 years. CONCLUSION Teenage pregnancy in Brasil is in slow decline, especially among mothers aged 10-14 years and is inversely associated with the HDI, except in the Northeast.