Sunday, July 06, 2008

Men past 35 sperm DNA decay

We have known there was a paternal effect for a while but we didn't expect to find these kind of miscarriage rates," he said in a telephone interview.

The researchers do not know exactly why but said a link between a man's age and DNA decay in sperm that causes it to fragment could be a likely explanation.

The sperm they studied showed that many samples taken from men over 40 had defects that could cause miscarriage, the researchers added.

"Until now, gynecologists only focused on maternal age, and the message was to get pregnant before the age of 35 or 38 because afterwards it would be difficult," Belloc added.

"But now the gynecologists must also focus on paternal age and give this information to the couple."

(Reporting by Michael Kahn; editing by Philippa Fletcher)



At 4:28 PM, Anonymous Anonymous said...

The evidence we have to date still places most emphasis on fertility on maternal age where there is a discrete, clearly-defined biological clock.

Sperm quality and paternal age is a more complicated issue, and relates more directly to the physical health of the father rather than paternal age per se.

Men under 25 and over 40 have a statistically significant increased risk of birth defects, but given the relatively low baseline probability of this occuring, the risk imparted by paternal age is trivial compared to that imparted by maternal age.

Male fertility is another issue, and some of the more sensationalist studies, which claim a significant drop in male fertility above 35, suffer from poor study design, as well as overrepresentation by an agenda-driven media.

Several of the larger retrospective studies and metanalyses done subsequently support the previously-held notion that the drop in fertility around that age bracket is relatively trival.


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