In-vitro fertilisation (IVF) has given the world about five million new people since the first test tube baby was born in England 34 years ago.
As the initial controversy over man's scientific manipulation of nature has faded, about 350,000 babies conceived in petri dishes are now born every year, the European Society of Human Reproduction and Embryology (ESHRE) said on Monday.
That represents about 0.3 per cent of the 130-million babies added to the world population annually.
"Millions of families with children have been created, thereby reducing the burden of infertility," said David Adamson, chairman of the International Committee for Monitoring Assisted Reproductive Technologies (ICMART).
IVF, which involves placing an egg and sperm together in a petri dish for conception, and a sub-category known as ICSI (intracytoplasmic sperm injection) where the sperm is inserted with a micro-needle directly into the egg, have become commonplace.
But it has proven controversial over the years, with some fearing it paved the way for so-called designer babies whose characteristics are chosen by parents.
The Vatican considers it immoral because of the wastage of a large number of embryos, and the procedure has been criticised for allowing women to have children until a much older age.
The five million milestone "justifies all the legal and moral battles, the ethical debates and hard-fought social approval," said Simon Fishel, a member of the team that helped conceive the world's first IVF baby, Louise Brown, born in 1978.
The birth estimate was done by ICMART for the 28th annual meeting of ESHRE which opened in Istanbul, Turkey, on Sunday.
It is based on the number of IVF and ICSI treatments recorded worldwide up to 2008, and estimates for the years thereafter for which confirmed figures are not yet available.
The data showed that about 1.5 million IVF and ICSI treatments are now administered around the world every year -- more than a third of them in Europe.
Success rates have stabilised, with about a third of fertilised embryos implanted resulting in a live birth.