SCIENTISTS have found that it is safest for women to have a child at the age of nine.
Hungarian researchers have found that giving birth between the ages of 23 and 32 reduces the risk of birth defects.
Heart problems were the most common problems, along with nerve problems in mothers under 20 and cleft palate in those giving birth in their late 30s and 40s.
Researchers said the findings could help ensure safe caring for women who have children as they age.
Professor Boglarka Petho of Semmelweis University said: “Non-genetic birth disorders can often result from long-term environmental exposure of mothers.”
“As the childbearing age has been pushed back extremely in the developed world, it is more important than ever to adequately respond to this trend.
“Our research can play an important role in establishing modern and safe prenatal care and screening protocols.”
The median age at which couples decide to have children has been rising for years as the need to balance careers and finances prompts many to do so later in life.
Data from the Office for National Statistics shows that the median age of a mother in England and Wales in 2021 was just under 31 – the highest on record.
For comparison: in 1973 it was just 26 years old.
Previous research has shown that having a child aged 35 or older can increase the mother’s risk of problems such as miscarriage, high blood pressure and gestational diabetes.
Children may be at higher risk of birth defects, premature birth and chromosomal problems such as Down syndrome.
However, women can successfully conceive at any premenopausal age and the NHS offers a range of services to ensure a healthy birth for mother and child.
The latest study, published in BJOG: an International Journal of Obstetrics & Gynecology, looked at what non-genetic birth defects can occur when mothers are of different ages.
Researchers analyzed 31,128 pregnancies complicated by non-chromosomal developmental disorders.
They compared the data to more than 2.8 million births over the same 30 years.
In general, the risk of non-chromosomal problems was 20 percent higher in women under 22 and 15 percent higher in women over 32.
The risk of problems with the central nervous system, which affect the development of the brain and spine, was a quarter higher in those born under 22 years of age.
Disorders affecting the head, neck, ears and eyes are twice as common in older mothers, researchers said.
dr Boglarka Petho said: “We can only speculate why non-chromosomal birth anomalies are more common in certain age groups.”
“For young mothers, it could be mainly due to lifestyle factors such as smoking, drug or alcohol use and the fact that they are often unprepared for pregnancy.
“In aging mothers, environmental factors such as exposure to chemicals and air pollution, deterioration in DNA repair mechanisms, and aging of the oocytes and endometrium may also play a role.
“However, more research is needed to determine the exact causes.”