Research: Male Biological Clock Winds Down After 35

CHARLOTTE, NORTH CAROLINA – Although age-related fertility decline is most typically attributed to women, new research further strengthens the reality of a male biological clock. According to a new study reported in the Aug. 1 issue of Obstetrics and Gynecology, sperm quality starts to go downhill after age 35 and indicates that paternal age is a significant risk factor for miscarriage. The study of almost 14,000 pregnancies (based on North Carolina and Iowa farm families), conducted by Dr. Karine Kleinhaus of Columbia University, showed that women with partners ages 35 or older had nearly a threefold increase in spontaneous abortions compared with women whose partners were younger than 25.

“Many of the male patients we treat were married later in life or in the course of their second or third marriages found they were unable to conceive—even if they had children from a previous marriage,” says Dr. Nancy Teaff, of the Reproductive Endocrinology Associates of Charlotte (REACH). “Sperm quality is clearly impacted as child-bearing is increasingly delayed – for both men and women. It is already well documented that fertility declines because of a limited number and quality of eggs for women as they get older, so is research should alert men to similar issues.”

It may be that the clock ticks even faster for overweight men. New research from the National Institute of Environmental Health Sciences showed that men with increased body mass index (BMI) were significantly more likely to be infertile than normal-weight men. A 20-pound increase in men's weight may increase the chance of infertility by about 10 percent. The majority of men who participated in the study were more than 30 years old. Obesity affects nearly one-third of the adult American population (approximately 60 million). According to the American Obesity Association, the number of overweight and obese Americans has continued to increase since 1960, a trend that is not slowing down.

The Columbia research found that the risk of miscarriage of a fetus conceived by a father over age 40 was 60 percent greater than if the father were 25 to 29, irrespective of other factors that have been linked with increased miscarriage risk, such as the mother's age, maternal diabetes, poor maternal health and smoking during pregnancy. The increased risk of miscarriage does not just apply to fathers in their 40s, however. The miscarriage risk in a pregnancy involving a father aged 35 to 39 was three times higher than the risk if the father were under 25.

Data from the study showed that 1,500 of the women suffered miscarriages, while 12,000 carried their children to term.

“This new study provides important information for people – of all ages – who are planning their families," says Dr. Teaff. “It means that men should be sure to get the medical attention they need to uncover medical problems underlying infertility.”

In fact, the American Society for Reproductive Medicine (ASRM) has set an upper age limit of 40 years old for semen donors because of the increased risk of genetic abnormalities in the offspring of older fathers. According to the ASRM, infertility is a male problem 35 percent of the time; a female problem 35 percent of the time, a combined problem of the couple 20 percent of the time, and the final 10 percent is unexplained.

About Reproductive Endocrinology Associates of Charlotte (REACH)

REACH is led by a nationally recognized team of five physicians who offer comprehensive, state-of-the-art assistance for infertile couples and women with reproductive endocrine problems. REACH physicians, all long-time practitioners in Charlotte, are widely respected for their superior pregnancy success rates – one of the highest in the region- and for the finest patient care. REACH is a member of IntegraMed, an exclusive network of fertility practices nationwide. For more information, visit www.REACHdrs.com.