It's been 34 years since Britain saw the birth of the first test-tube baby; since then, another 5 million people have been born through in vitro fertilization. Some 350,000 are born each year, amounting to 0.3% of births across the globe, the AFP reports. Some 1.5 million IV procedures occur annually, with more than a third of those in Europe.
About a third of implanted fertilized embryos are successful. European doctors have lately been implanting fewer embryos at a time over concern for the health of both mother and child. Triplets now occur less than 1% of the time, and twins less than 20%—a new record. The 5 million milestone "justifies all the legal and moral battles, the ethical debates, and hard-fought social approval," says one of the doctors involved in the birth of the first IVF baby in 1978.