Many women are waiting until they are older to give birth.

The trend for having children later in life could lead to women becoming more fertile in their 40s, experts at a UK university have suggested.

As many women wait until they are older to give birth, only those with longer lasting fertility genes will be successful.  That means the average length of fertility will grow as their genes will be passed on to their children.

The study from the University of Sheffield shows previously women would marry early and if widowed were too old to remarry thus favouring early childbirth in women, the Daily Telegraph reported. But today’s reluctance to settle down and reproduce until later in life could lead to fertility beginning to favour older women.

Duncan Gillespie, of the University of Sheffield said in today’s society women do not start childbearing until an older age as marriage is often delayed. “As a result of this, the natural selection maintaining young-age fertility might weaken and relative strength of natural selection on old-age fertility could increase, that could potentially lead to improvements in old-age fertility over many generations,” he said.

“Now family-building appears to be increasingly postponed to older ages, when relatively few women in our evolutionary past would have had the opportunity to reproduce.” he added.

Via Times of India