Thursday, February 01, 2007

Sperm from Older Men: Safe for Kids?

There is lots of debate whether it is moral or medically prudent for a woman of "advanced maternal age" to bear children, especially when reproductive technologies are involved. But there has been relatively little discussion of older men producing off-spring. Turns out, sperm from men of advanced paternal age can put kids at risk for all sorts of health problems.

Blog reader Leslie Feldman emailed the following interview with Dolores Malaspina, MD, MSPH, professor of psychiatry at Columbia University College of Physicians and Surgeons, and director of the Medical Genetics Division of Clinical Neurobiology at New York State Psychiatric Institute in New York City (try to get all that on a business card.) Here is a snippet:

What is the most irrefutable finding that you and your colleagues have made?
The most irrefutable finding is our demonstration that a father’s age is a major risk factor for schizophrenia. We were the first group to show that schizophrenia is linearly related to paternal age and that the risk is tripled for the offspring of the oldest groups of fathers. This finding has been born out in every single cohort study that has looked at paternal age and the risk for schizophrenia.

And this interview with Michael Craig Miller, MD, Harvard Medical School:

Should Older Men Stop Fathering Babies?

It's true that medical technology and general improvements in health have made life much more enjoyable for people in middle to late life. Maybe 50 is the new 30 when it comes to some aspects of aging. But a healthy and active lifestyle does not make 50-year-old sperm the new 30-year-old sperm. The increased risk of passing on any genetic vulnerability to a child is significant when you are older. When it comes to autism, however, the numbers are sobering. A man younger than 30 has no more than a 1 in 1,000 chance of fathering a child with autism. But the risk bumps up to approximately 3 in 1,000 for a man in his 40s and 5 in 1,000 above age 50. If a father in his fifties has a son, the risk of autism may approach 1 in 100.

And this abstract:

Parental Age, Family Size, and Risk of Multiple Sclerosis.

Background: Family structure, such as having siblings, provides proxy measures for a variety of characteristics relevant to disease risk. The etiology of multiple sclerosis (MS) is not well defined and analysis of family structure may provide etiologic clues. We conducted a case-control study to examine possible associations.

Results: Having 3 or more younger siblings, compared with none, produced an adjusted odds ratio (OR) for MS (with 95% confidence interval) of 0.80 (0.70-0.92) (adjusting for number of siblings, twins, maternal and paternal age, parental MS, sex, father's social class, county and year of birth). With 3 or more older siblings, the adjusted OR was 0.83 (0.72-0.96). Different-sex twin pairs compared with singletons had an OR of 0.59 (0.37-0.95) for MS. The risk of MS increased steadily with father's age but not mother's age, up to 2.00 (1.35-2.96) for 51- to 55-year-old fathers (compared with 21- to 25-year-old fathers).

Makes you wonder why the question of older fathers doesn't get more attention in the media.


Leslie Feldman said...

It is interesting how the new CDC study ignores the issue of increasing average paternal age since 1980 and the increase in autism. An upswing due to paternal age has been predicted and expected by NARSAD

Dr. Leonid Gavrilov, Ph.D. said...

Thank you for your interesting post!
I thought perhaps you may also find this related scientific study interesting to you:
Human Longevity and Parental Age at Conception

Anonymous said...

A new article that women and men should read and discuss. FYI