Partner Series
Time on His Side? Jagger a Dad Again at Age 72
Just call him "mother's little helper."
Credit: JStone/Shutterstock.com

A father at age 72? That's how strong his love is.

Mick Jagger, the septuagenarian lead singer of the Rolling Stones, is expecting his eighth child — his first with 29-year-old partner, Melanie Hamrick. Hamrick and Jagger are "surprised and happy" with her pregnancy, The Sun reported on July 14.

You might say Jagger would be a fool to cry over the happy news. But fathering a child at his age — he will be 73 when the baby is born — is not without attendant risks, studies have found. Though there are instances of men retaining fertility into their 90s, recent studies show that when it comes to overall sperm quality, time is not on their side. [Sexy Swimmers: 7 Facts About Sperm]

Epidemiologists have noted that there is an increased risk of certain conditions, particularly schizophrenia and autism, in children who have older fathers, according to Brian Lee, an associate professor of epidemiology and biostatistics with the Dornsife School of Public Health at Drexel University in Pennsylvania.

"Both older mothers and older fathers are more likely to have children with autism" than younger parents are, Lee told Live Science. "But stronger effects seem to have been found with older fathers, for both autism and schizophrenia."

Lee explained that every time cells divide, there's a chance for an error to become incorporated into the cells' genetic code. When that happens in sperm cells, children can inherit those errors, or mutations.

"And the older you are, the more mutations are likely to build up," Lee said.

Kari Stefansson, chairman and CEO of deCODE Genetics in Reykjavik, Iceland, told Live Science in 2012 that as men age, the likelihood increases that a mutation in one of their sperm cells could affect an important gene, resulting in a serious disease in offspring.

Stefansson said that a 36-year-old father gives twice as many new mutations to his child as a 20-year-old father does.

"And a 50-year-old father gives about four times the number of mutations," he added.

Stefansson noted that a 40-year-old man is twice as likely to father a child who will develop autism or schizophrenia, adding that recent increases in autism diagnosis may be explained in part by a growing number of older fathers.

Beyond genetic mutations, additional damage can also occur in sperm cells in aging fathers. That is, DNA fragmentation, or general deterioration that changes or degrades the information produced by the fathers' genes, can also degrade genetic material in these cells, according to a study Lee co-authored in 2015, published in the journal Cell Press.

But before older men concede that it's all over now if they're hoping to father a child, some research suggests that options may exist for slowing the deterioration of sperm quality.

A study published in 2012 in the journal Fertility and Sterility found that male participants over the age of 44 whose diet was rich in vitamin C showed about 20 percent less damage to their sperm's DNA than the men in the study who consumed the lowest amount of vitamin C.

Daily ejaculation might also help reduce DNA damage to sperm, according to a study presented in 2009 at the annual meeting of the European Society of Human Reproduction and Embryology in Amsterdam.

Nonetheless, a successful pregnancy may still be more than just a shot away, no matter how ardently older men follow these recommendations. A 2004 study published in the American Journal of Obstetrics & Gynecology found that in 221 couples trying to conceive through in vitro fertilization or gamete intrafallopian transfer, their chances decreased by 11 percent for every additional year of the man's age.

As Jagger himself once sang — you can't always get what you want.

Original article on Live Science.