It's not just women who have biological clocks, British researchers reported on Wednesday.

As men get older, it takes them longer to father a child, the team at the University of Hull reported.

Doctors have long known that the older a woman is, the more trouble she will have conceiving. Men can, at least theoretically, father children until they die.

But a study of more than 1,200 pregnant women showed it is not always easy.

Mohamed Hassan and Dr. Stephen Killick questioned the women about everything from whether they smoked to how long it took them to become pregnant. The time it took them to get pregnant, they found, became noticeably longer when their partners were 45 or older.

"As with women's age, increasing men's age was associated with significantly rising time to pregnancy and declining conception rates," they wrote in their report, published in the journal Fertility and Sterility.

"Half the couples trying for pregnancy succeed within three months," they wrote. Eighty-five percent succeed within a year.

One in six couples has trouble conceiving within a year, although 70 percent finally succeed after two years.

Even adjusting for factors like frequency of intercourse and the age of the woman, it took a man five times longer to father a child if he was over 45, they reported.

"Age is not only a female problem," Dr. Marian Damewood, president-elect of the American Society of Reproductive Medicine, which published the report, said in a statement.

"Many patients are frustrated by the length of time that it takes them to conceive." she added.

"This study is valuable because it provides a broader view of the bottom-line effects of male aging on fertility." 

Close

Today's Top News		Top Lifestyle News
+The next great leap after Shenzhou V ( 2003-10-21) +Hu calls for balanced development ( 2003-10-21) +Report: SARS not airborne virus ( 2003-10-21) +Japan urged to resolve weapons issue ( 2003-10-21) +Int'l AIDS group opens Beijing office ( 2003-10-21)		+Landmark Disney concert hall dedicated in Los Angeles ( 2003-10-21) +Growth of 30 percent Chinese babies impaired by lack of breast ( 2003-10-21) +Increasing tourists flock to Tibet ( 2003-10-21) +Hollywood actress-singer signs deal to produce TV talk ( 2003-10-21) +China urged to build up talent pool of financial mathematicians ( 2003-10-21)