Women naturally are fertile between puberty and menopause. For most women, fertility peaks during their mid-late 20's and gradually starts to decline after the age of 32. After age 35 women often face difficulties conceiving naturally as the number of eggs and the quality of ova starts to decline, yet researcher believe a woman's fertile age will change to reflect the modern childbearning trends.

The age of fertility is largely based upon genetics; if a mother suffers premature menopause, any daughters are likely to follow the same fertility path. If a mother conceives naturally at 40, daughters are likely to have a similarly extended fertility age.

A prediction by University of Sheffield reseachers, based on an analysis of marital and childbearing statistics from the past two centuries, suggests that marriage patterns may lead the way to an overall decline in fertility while at the same time, boost the average age of fertility in those women able to conceive naturally.   

Scientists believe that as women delay childbirth, fewer women will be able to get pregnant without assistance from infertility specialists. More women who conceive naturally will do so after the age of 35 - a later-then-normal age for natural conception - will pass on these longer-lasting fertility genes to their children. As a result, daughters conceived naturally will inherit genes allowing them to conceive later and this pattern will continue. Children who are conceived through

IVF and also choose to delay pregnancy will suffer the same age-related fertility problems as their mothers, leading to the statistical decline of fertility. 

Currently, the average age of pregnancy is increasing as more women choose to delay children for careers and people marry later. Infertility specialists are advancing in techniques to help these women affected by age-related infertility conceive. Requests for egg donations are soaring with many women traveling abroad to find donor eggs and an increasing number of younger women are taking precautionary fertility preservation methods and freezing healthy eggs for later use in IVF. Specialists are considering the option of egg banks to cope with the rising age-related fertility problems to offer women greater choice and assistance overcoming infertility.