In some 35 years people will have sex just for fun, without worrying about contraception. Babies will be conceived from frozen eggs and sperm, the father of the birth control pill says. He predicts people with no fertility problems will turn to IVF.

"Women in their twenties will first choose this approach [in vitro fertilization, IVF] as insurance, providing them with freedom in the light of professional decisions, or the absence of the right partner, or the inexorably ticking of the biological clock," Austrian-American chemistry professor Carl Djerassi said in an interview with the Daily Telegraph.

"For them the separation between sex and reproduction will be 100 percent," said 91-year-old Djerassi, who is known as the "father of the Pill".

The emeritus professor of chemistry at Stanford University played a crucial role in the development of birth control medication in 1951. A century after its invention, the contraceptive, which tricks the body into thinking it's pregnant to avoid actual conception, will no longer be necessary, the professor claims.

When asked about a male contraceptive pill, the researcher said it was "unlikely," as trials would need decades to prove the method has no unwanted effects on sperm quality.

The pill will become outdated, as men and women will instead opt to freeze their reproduction cells at a young age before being sterilized. Advances in fertility treatment will make it safer for healthy parents with no fertility problems to consider IVF.

"I predict that many of these women will in fact decide to be fertilized by IVF methods because of the advances in genetic screening. And once that happens, then IVF will start to become a normal non-coital method of having children," Djerassi told the Daily Telegraph, adding that the new attitude will end abortions, and reduce cases of non-planned pregnancy.

Children born through IVF may be healthier, as they will be conceived with "younger" eggs and sperm, and when they themselves become parents they will be safer in the knowledge that having babies can be delayed without repercussions.

If the professor's predictions are true, people will concentrate more on building successful careers and having sex for fun, knowing they can use the IVF method to become parents any time they want.

Currently, the chances of women becoming pregnant after 45 are considered slim, even negligible if using the woman's own eggs. According to disease control and prevention centers, almost half of women over 40 have fertility problems. They have about a two-percent chance of getting pregnant in their mid-forties, compared to a 75-percent possibility for a woman 10 years younger.