Late pregnancy: impact on prematurity and newborn’s weight

• Autor(a) principal: Shimamura,Lia Keiko Sousa
• Data de Publicação: 2021
• Outros Autores: Monteiro,Denise Leite Maia, Silva,Célia Regina da, Morgado,Flávio Eduardo Frony, Souza,Flávio Monteiro de, Rodrigues,Nádia Cristina Pinheiro
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Revista da Associação Médica Brasileira (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0104-42302021001201550
• topic: Prematurity; Maternal age; Fertility rate; Pregnancy complications; Low birth weight

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.