Scientists believe they’ve identified the safest age for women to have children.
Researchers from Semmelweis University in Budapest, Hungary, analysed 31,128 pregnancies complicated by non-chromosomal developmental disorders, and compared the data with 2,808,345 births registered over the same 30 years.
They suggested the safest age to have a child is between 23 and 32 years old, as the chances of certain birth defects are the lowest at this point.
What did the study find, specifically?
Previous research has confirmed the correlation between genetic disorders (for example, Down’s syndrome) and maternal age.
In this particular study, researchers found that the risk of developing non-chromosomal abnormalities increased by 20% for births under the age of 22 and by 15% above the age of 32, compared to the age of 23-32 years old.
Of anomalies affecting only young mothers, central nervous system malformations of the foetus were the most prominent.
Among the abnormalities affecting the foetuses of older mothers, the risk of congenital disorders of the head, neck, ears and eyes showed a doubled increase (by 100%), which was significantly more noticeable in pregnancies over the age of 40.
A large increase (34%) in congenital malformations of the urinary system were also detected in the foetuses of advanced maternal age.
Among the possible abnormalities affecting both age groups, the risk of heart defects was 7% higher in the foetuses of young mothers (below 22) and 33% in the case of more mature mothers (above 32).
The risk of developing cleft lip and palate can increase by 9% in children of young mothers and by 45% in pregnancies over the age of 32, researchers said.
The results were published in the journal BJOG: an International Journal of Obstetrics & Gynaecology.
Why do these abnormalities happen?
“We can only assume why non-chromosomal birth anomalies are more likely to develop in certain age groups,” said D. Boglárka Pethő, assistant professor at Semmelweis University and the study’s lead author.
“For young mothers, it could be mainly lifestyle factors (e.g., smoking, drug or alcohol consumption) and that they are often not prepared for pregnancy.
“Among advanced-aged mothers, the accumulation of environmental effects such as exposure to chemicals and air pollution, the deterioration of DNA repair mechanisms, and the ageing of the eggs and endometrium can also play a role.”
They noted further research is needed to identify the exact causes.
“Non-genetic birth disorders can often develop from the mothers’ long-term exposure to environmental effects,” said Professor Nándor Ács, director of the Department of Obstetrics and Gynaecology at Semmelweis University.
“Since the childbearing age in the developed world has been pushed back to an extreme extent, it is more important than ever to react appropriately to this trend.
“Our research can play an important role in establishing modern and safe pregnancy care and screening protocols.”