Risks of Older Men Having Babies
A typical man can produce as many 250 million sperm a day — over 2,000 sperm a second. As men create fresh sperm even into old 70s and 80s, it might seem that age wouldn’t affect their fertility.
The process of repeatedly copying sperm can lead to small errors or mutations, however, increasing the risk of a bad outcome if a man fathers children after age 35.
Miscarriage, or a pregnancy loss before 20 weeks, is a common complication of pregnancy. A 2016 study published in “Obstetrics & Gynecology” and led by Dr. K. Kleinhaus reports that women who conceived with men over 35 had almost three times the risk of miscarriage as those impregnated by a man under 25.
A 2015 study by Rémy Slama, et al., and published in the “American Journal of Epidemiology,” only looked at miscarriages after six weeks’ gestation, but found similar results: Women with partners age 45 and older had almost twice the miscarriage rate as those conceiving with a man under 25.
Abnormalities in a baby’s body structure and function affect one in 33 babies. The chance of these abnormalities increases with a father’s age, reported Jin Liang Zhu, et al., in a 2015 Danish study published in “Human Reproduction” that looked at an extensive list of congenital defects.
Incidences of Down syndrome, syndromes affecting more than one body system and limb abnormalities were 30 to 40 percent more common in babies with fathers 40 and older than babies fathered by men under 30.
Schizophrenia is a brain disorder characterized by symptoms such as hallucinations and dysfunctional thought patterns. A 2011 study led by Dr. Dolores Malaspina and published in the “Archives of General Psychiatry” found that a man’s odds of fathering a child with this disorder increase as he ages, and men over 50 have a risk three times that of men under 25.
According to a 2016 study also published in the archives and led by Abraham Reichenberg, autism appears almost six times as frequently in children born to fathers 40 as those with fathers under 30.
Poor Birth Outcomes
Advanced age in men is also a risk factor for problems affecting a baby’s health at birth. A 2012 study in “Epidemiology” by Susan Harlap, et al., reports that women conceiving with men over 35 face an increased risk of pre-eclampsia — high blood pressure and protein in the urine — which can lead to prematurity, breathing problems at birth and stillbirth.
For men over 45, the risk was almost double that of men between the ages of 25 and 34. A study from 2016, published by researchers Nancy E. Reichman and Julien O. Teitler in the “American Journal of Public Health,” found an association between paternal age and low birth weight.
Smaller babies face increased risk of physical and cognitive problems, and men 35 and older were almost twice as likely to father low birth weight babies as those between 20 and 34.