Gender equality: Aging egg and sperm are both problematic
By Cindy Haines, M.D., Special to the Beacon
Posted 10:30 a.m. Fri., Feb. 13 - The trend is clear. Women and men are postponing starting -- or adding to -- their families until their mid to late 30's and beyond. While the proverbial biological clock has historically been in reference solely to females, a growing body of evidence points to a tick-tick factor for males, as well. The number of births in the United States to men aged 40 to 49 has almost tripled between 1980 and 2004, according to the National Center for Health Statistics, making this biological clock analysis more relevant than ever.
Aging dad and infertility
When one thinks of infertility, thoughts may go directly to the female, with a secondary thought of whether or not the male is able to produce viable sperm. If sperm production is a "go", a common assumption may be made that difficulties conceiving or delivering a healthy baby are factors resting exclusively on the woman. Not necessarily so, according to accumulating data on the subject.
In an analysis of couples struggling with fertility problems, lower pregnancy rates and increased risk of miscarriage were seen in cases whereupon the man was age 35 and older. This finding comes from study presented in 2008 at the European Society of Human Reproduction and Embryology annual conference in Barcelona.
French researchers studied over 12,000 couples seeking care at a fertility clinic where the majority was being treated due to the man's infertility. Collectively, the couples underwent a total of 21,239 intrauterine inseminations (IUIs). Not surprisingly, women over age 35 had a reduced pregnancy rate compared to younger women (8.9 vs. 14.5 percent, respectively).
"But we also found that the age of the father was important in pregnancy rates -- men over 35 had a negative effect. And, perhaps more surprisingly, miscarriage rates increased where the father was over 35," said Dr. Stephanie Belloc, of the Eylau Center for Assisted Reproduction in Paris and author of the study. "Our research proves for the first time that there is a strong paternal age-related effect on IUI outcomes, and this information should be considered by both doctors and patients in assisted reproduction outcomes."
Dr. Peter Ahlering, medical director of SHER Institutes for Reproductive Medicine in St. Louis, agrees that age of would-be fathers may well have an effect on successful pregnancies. "Much of this impact is likely due to environmental exposures which may have an impact on sperm quality," he said
The American Society for Reproductive Medicine on infertility
Archives of General Psychiatry:
Abstract - Frans
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Ahlering uses HRSS -- high resolution sperm selection -- in the quest for the highest quality sperm. "You can select out under high magnification the sperm to use during [assisted reproductive technologies]," he explains. "You can select out sperm with visible abnormalities which has the effect of increasing fertilization efforts." And the chance of a healthy baby, to boot.
Aging dad and mental illness in his offspring
Advanced paternal age has also been linked with an increased risk of birth defects, including cleft palate and dwarfism. Recent reports have also suggested that children of men who were 40 or older may be up to 6 times more likely to develop autism, jumping to a nine-fold risk when the father's age reaches 50 and beyond. Other mental illness seen more commonly in offspring of aging dads: schizophrenia. A child born to a 40-year-old father may have double the risk of schizophrenia than if the child is born to a father 30 years old or younger.
Children of older fathers may also have a higher risk of bipolar disorder (alternating bouts of mania and depression), according to the results of research published in the September issue of the Archives of General Psychiatry. Over 13,420 subjects with a diagnosis of bipolar disorder were studied. Children of men who were at least 55 years old had a 37 percent greater chance of a bipolar diagnosis compared to children of men ages 20 to 24. The risk was even greater in cases of early-onset disease, suggesting greater severity of disease linked with advancing paternal age.