While attention is generally paid to older women's ability to become pregnant, a new study indicates that women are not the only ones whose biological clocks begin ticking in their 30s. Research involving 8,500 British couples reveals that once a man passes age 24, the older he is the longer it takes him to get his partner pregnant (regardless of her age). This is believed to be the first study to confirm a decline in male fecundity, which is the likelihood of achieving pregnancy within a certain period of time. It is also the first clear indication that the age of a man should be factored in with the age of the woman when considering the prognosis for infertile couples.