The birth of a child after 40 becomes more and more common – but may result in an increased risk for the child. A new study based on data from more than 300,000 births in Sweden shows that the children of older mothers are more frequent or complicated, especially when the mother is 45 years and older.
In large parts of the world, women have children later and later in life. In Sweden, 4.8% of mothers were 40 years of age or older in 2022. Previous surveys showed that older mothers were different from younger mothers in various respects, such as the existence of a higher BMI, a higher percentage used by assisted reproductive technology, increased risk of disease. In this spirit, researchers in the current study wanted to explore how the mother’s age influenced the health of her newborn baby.
Increased risk of mortality
In the study, which is published in Acta pedriaticaThe researchers examined data from the Swedish National Medicine Nativity Register, which is maintained by the Swedish National Council of Health and Welfare and includes all pregnancies from the 22nd week leading to childbirth. A total of 312,221 children born to women over 34 years of age during the period 2010-2022 were included in the study, excluding twin births. Babies were divided into three groups depending on their mother’s age: 35-39 years, 40-44 years and 45 years or older. The researchers were particularly interested in how the child’s health was affected at birth when their mother was over 39 years old. Children born to mothers aged 35-39 years served as a reference group.
First of all, we could see that for babies born in Sweden, serious complications are rare, regardless of the mother’s age. But we also found that the children of older mothers have a higher risk of mortality, premature birth, low birth weight than pregnancy length and low blood sugar compared to babies born to mothers aged 35-39 years. The study showed that the highest risks of all were in babies born to mothers 45 years of age or older. ”
Sofia Voss, Head writer of the study
Thillbirth is unusual in Sweden, but happened in 0.83% of pregnancies in women who were 45 years old and older. This can be compared to 0.42% in women aged 35-39 years.
As for premature birth, 4.8% of these cases occurred in the group of mothers aged 35-39 years. Among women aged 40 to 44 years, the corresponding number increased to 6.1% and among women aged 45 and over, 8.4% of their babies were born prematurely.
Helps the healthcare system in designing the right interventions for older mothers
Previous studies are mainly compared to babies born to young mothers with those born to older mothers. In the present study, researchers are interested in getting a more detailed picture of the distribution of risk between older mothers.
“By comparing different series of advanced age at birth, the study can also contribute to better and better targeted information for women who are designing future pregnancies.
The study was conducted in collaboration between researchers from the University of Upsala and the University of Linköping.
Source:
Magazine report:
Voss, S., et al. (2025). Neonatal effects between mothers with advanced mother age: a national cooker study. Acta paediatrica. doi.org/10.1111/apa.70185
