The Clock Ticks For Men, Too

The newest reports tell us that there is a decline in the rate of pregnancy and an increase in the rate of miscarriage where the father is past the age of 35. This was the conclusion of Dr. Stephanie Belloc, as given at the 24th annual conference for the European Society of Human Reproduction and Embryology, which was held on July 7, 2008 at the Eylau Centre for Assisted Reproduction, in Paris, France. This is a significant finding since it is the first evidence that there is a major paternal influence on conception and miscarriage rates.

Male Partners

To obtain these findings, Dr. Belloc and her research team examined the results of 21239 intrauterine insemination procedures (IUI) where the husband's sperm was employed. In the majority of these cases, the procedure was performed as a result of the male spouse's infertility. Prior to IUI, the husbands' sperm were analyzed for count, motility, and structure. The rates of both miscarriage and delivery were recorded as scientists tried to eliminate factors affecting conception which were unrelated to the age of the male partners.

Scientists already knew that maternal aging correlates to a decrease in the rate of pregnancy. This study echoed these previous findings, showing that women over the age of 35 had an 8.9% decrease in conception rates as compared to a 14.5% rate of conception in younger women. Miscarriage too, bears a similar correlation to maternal aging, though the surprise in this study was that paternal age is an important factor in conception and miscarriage rates.

Sperm Decline

Belloc's study demonstrates that men over 35 cause their partners a decrease in the rate of conception and an increase in the rate of miscarriage. Earlier research had shown that sperm undergoes a decline as men age, both in quality and count, but until this time, there was no proof positive that aging fathers bore a specific responsibility for the couple's fertility. Dr. Belloc explains that fertility experts had already known that couples take longer to conceive where the father is older, but never had clinical studies been performed to examine how miscarriage rates increased along with the father's age. Of late, some studies had shown a link between DNA damage and paternal age, and this finding was the catalyst for Belloc's current area of research.

While this study is already large scale, it is expected that the work will be expanded over the next several years with more couples furnishing further data to the scientists working on this project. The researchers hope that this added data will add weight to their current conclusions, since this may have important ramifications for couples who hope to undergo IVF or ICSI procedures.

Over 35

Dr. Belloc believes that IVF or ICSI is indicated for infertile couples over the age of 35. "In IVF, the zona pellucida (the outer membrane of the egg) seems to be an efficient barrier in preventing the penetration of sperm with DNA damage, and in ICSI, the best sperm can be selected out for use. These methods, although not in themselves a guarantee of success, may help couples where the man is older to achieve a pregnancy more quickly, and also reduce the risk of miscarriage," says Belloc.