One of the men behind the development of in-vitro fertilisation (IVF) has been awarded the 2010 Nobel Prize for medicine.
Dr Robert Edwards of Britain won the prestigious prize for his work on IVF, which has helped millions of infertile couples to have a child.
"His contributions represent a milestone in the development of modern medicine," the Nobel Assembly at the Swedish Karolinska Institute said.
"His achievements have made it possible to treat infertility, a medical condition afflicting a large proportion of humanity including more than 10 per cent of all couples worldwide," it added.
The IVF procedure entails taking an egg from a woman and fertilising it in the lab-dish with sperm donated from a man.
The egg divides, is allowed to develop into an early-stage embryo and is then inserted in the woman's uterus where, if all goes well, it will become a baby.
Mr Edwards began working on developing the process in the 1950s and "his efforts were finally crowned by success on July 25, 1978, when the world's first test-tube baby was born," the prize jury said.
Since Louise Brown's birth, about 4 million people have been born through IVF.
"A new field of medicine has emerged, with Robert Edwards leading the process all the way from the fundamental discoveries to the current, successful IVF therapy," the jury said.
Mr Edwards developed his laboratory findings "from experiment to practical medicine" with the help of British gynaecologist Patrick Steptoe, who died in 1988.
Together they established the Bourn Hall Clinic in Cambridge, the world's first centre for IVF therapy.
Today, 20% to 30% of eggs fertilised by IVF lead to the birth of a child.
The Medicine Prize kicked off a week of prestigious award announcements, with the two most watched, Literature and Peace, to be announced on Thursday and Friday.
The announcements of the Physics and Chemistry prizes will be announced Tuesday and Wednesday, and the Economics Prize will wrap up the Nobel season next Monday.
This year's laureates will receive 10 million Swedish kronor ($1.5 million) which can be split between up to three winners per prize.