When it comes to male fertility, age matters

The relationship between female age and fertility is well established and discussed extensively in previous blogs. But when it comes to male fertility, age is rarely discussed. So, do men need to think about their biological clocks ticking?

Research by R. Ramasamy and colleagues at Baylor College of Medicine in Houston indicates that male aging can contribute to infertility. Here are some interesting findings from their study:

Does it take longer for a woman to conceive with an older man?

Yes. One large study, the Avon Longitudinal Study of Pregnancy and Childhood, investigated the effect the paternal age has on the length of time to conception. The outcome found was men 35 or older had a 50% lower chance of conceiving within 12 months than men that were under 25 years old.

What specific changes occur when a man gets older?

• Testosterone levels decrease with age. This contributes to decreased libido, decreased frequency of intercourse and erectile dysfunction.
• Sperm quality decreases with age. Semen analyses in older men show decrease in semen volume, sperm motility and shape (morphology). The sperm count may or may not change.
• Sperm function, especially the ability to fertilize an egg is compromised with age. This could be due to increased DNA fragmentation. Treatment with anti-oxidants and varicocele repair can reduce DNA fragmentation.

Does male age affect miscarriages?

A large prospective study of 23,821 pregnant women (the Danish National Birth Cohort study) from 1997 to 1999 showed that pregnancies initiated by men 50 or older had a twofold increased risk of ending in fetal loss. The risk of miscarriage is much higher in couples where the woman is greater than 35 y and the man is greater than 40 years old.

What is 'advanced paternal age'?

There is no general consensus on the definition of advanced paternal age. Some studies have used a threshold as low as 35 y, however, others have found significant problems only when the age is greater than 55 years. Many sperm banks will not accept donors that are older than age 40 y.

Does male age affect birth defects?

Advanced paternal age can contribute to birth defects associated with single gene mutations, chromosomal abnormalities and malignancies.

Achondroplasia (the most common cause of dwarfism) was the first genetic disorder to be influenced by paternal age (relative risk 7.8, population risk 1/15,000.

Studies of chromosomal abnormalities (aneuploidy) in sperm show that all chromosomes are susceptible to nondisjunction but chromosomes 21, 22 and the sex chromosomes display an increased frequency of aneuploidy.

The incidence of leukemia, breast cancer and central nervous system cancers is also increased in children born to older fathers.

Conclusions About Male Fertility and Age

Older men who wish to conceive a child need to be informed of the risks and conditions that can occur in their offspring. Today there are no screening or diagnostic tests that target the different conditions that are increased with paternal age. Couples need to be counseled, since there is no agreement on the identity of a point at which advanced paternal age begins, the risks in offspring increase continuously over time.

To see a fertility specialist with decades of experience diagnosing and treating both male and female infertility, make an appointment at one of InVia’s four Chicago area fertility clinics.