Owing to a host of sociocultural changes, women are both getting married later and choosing to have a baby later in life as compared to a couple of generations ago.
Higher education, a longer time required for financial independence and inability to find a suitable match are some of the other issues that modern women have to deal with.
As a result, they find that they are approaching the end of the biological spectrum for childbearing. While modern science has devised a wide variety of methods for helping extend female fertility, there is no foolproof workaround yet.
This article at BBC Future examines the science associated with extending fertility into the fourth and fifth decade of life in an easy to understand manner from the point of view of the layperson.