However, hormone-replacement therapy does not maintain a woman's fertility into old age. Lexi Krock is editorial assistant of NOVA Online.

Their research is the first to indicate that female fertility declines before the age of 30. But the doctors said the older women studied were not less able to conceive - it just took them longer.

The researchers found that old males have more sperm than ... it is just the presence of seminal fluid or its age too that affects male fertility, and to understand the role of female sperm ...

24, JANUARY - JUNE 2011 A new relational method for smoothing an... Age-specific fertility rates can be smoothed using parametric models or splines. Alternatively a relational model can be used which ...