Mother’s age as a risk factor of birth defects

Abstract

Objective. To analyze the age structure of the mothers of children with birth defects and to assess the age-related risks of chromosomal and non-chromosomal congenital anomalies.Material and methods. The authors analyzed the data from 23 regional registers of birth defects from 2011 to 2018. There were total 5 047 468 births during this period. The authors calculated the incidence and relative risks of chromosomal and non-chromosomal birth defects in different age groups of mothers: under 20, from 20 to 34, from 35 to 39, 40–44, and above 45 years old.Results. The incidence of chromosomal abnormalities significantly increases with the mother’s age. The relative risk (RR) of chromosomal abnormalities in different age groups: 4,67 (95% CI 4,44–4,92) in Group 35-39, 15,00 (95% CI 14,10–15,96) in Group 40–44, and 26,49 (95% CI 21,89–32,07) in Group ≥45 as compared with the main age group of 20–34 years old. The authors also revealed the dependence of the non-chromosomal birth defects on the age of the mother: RR 1,15 (95% CI 1,08–1,23) in Group <20 years, RR 1,18 (95% CI 1,13–1,23) in Group 35–39, RR 1,35 (95% CI 1,24–1,47) in Group 40–44, and RR 2,03 (95% CI 1,47–2,79) in Group ≥ 45 years old.Conclusion. The study demonstrates the dependence of chromosomal and non-chromosomal birth defects on the mother’s age.