Pregnancy After 45 Comes With Elevated Health Risks To Both Mom And Baby

UPPSALA, Sweden — You’ve built your career, found the right partner, and now you’re ready to start a family at 45. Nearly 5% of Swedish babies are now born to mothers over 40, but a study tracking over 312,000 births has uncovered troubling health risks that increase significantly with each passing year.

Swedish researchers discovered that women who give birth at 45 and older face nearly double the risk of stillbirth compared to those in their late thirties. Their babies are also 82% more likely to develop dangerous low blood sugar levels and 68% more likely to be born prematurely, complications that can affect both mother and child for years.

While severe outcomes remain relatively rare, the research, published in Acta Paediatrica, shows that each additional year of maternal age incrementally raises the odds of problems with lasting consequences.

Examining Over 300,000 Births

Researchers at Uppsala University examined Sweden’s comprehensive Medical Birth Register, analyzing every singleton birth to mothers aged 35 and older between 2010 and 2022. They divided women into three groups: ages 35–39 (the comparison group), 40–44 (advanced maternal age), and 45 and older (very advanced maternal age).

Sweden’s healthcare system meticulously tracks pregnancy outcomes, giving researchers access to detailed information on more than 312,000 births, representing nearly a quarter of all singleton births in the country during that period. Of these births, 81% were to women aged 35–39, 18% to women aged 40–44, and just over 1% to women 45 and older. Remarkably, 6% of women in the oldest group were actually 50 or older when they gave birth.

Health Risks Climb Sharply After 45

Women in the oldest age group faced significantly higher rates of pregnancy complications. Beyond the increased stillbirth risk, babies born to mothers 45 and older were 46% more likely to be small for gestational age, a condition that can cause immediate problems like difficulty maintaining body temperature and blood sugar, plus long-term developmental issues.

Low Apgar scores, which measure a newborn’s condition immediately after birth, were more common among babies born to older mothers in the 40–44 age group. However, the most concerning finding was the dramatic spike in hypoglycaemia, or dangerously low blood sugar, among newborns of the oldest mothers. Without quick treatment, this condition can cause seizures and brain damage.

Mothers themselves showed distinct patterns as well. Women in the oldest age groups were more likely to be shorter, have higher body weights, and suffer from diabetes and high blood pressure. They were also far more likely to have used fertility treatments—18% of women 45 and older compared to just 6.7% of women in their late thirties.

Nearly half of the oldest mothers (46%) delivered via cesarean section, compared to less than 23% of women aged 35–39, reflecting both increased complications and more cautious medical approaches.

Implications for Family Planning

The research doesn’t suggest women should panic about delaying childbirth, but it does provide important context for family planning decisions. Understanding these risks allows women and their healthcare providers to make informed choices and potentially take steps to minimize complications.

For women who do conceive later in life, the study underscores the importance of excellent prenatal care and close monitoring throughout pregnancy. Many complications can be managed effectively when caught early.

Modern medicine has made pregnancy safer at all ages, but it hasn’t eliminated the fundamental biological challenges that come with aging. Women considering pregnancy after 40, and especially after 45, deserve complete information about potential risks, even if they remain relatively small in absolute terms.

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