Five million "test-tube babies" have now been born around the world, according to research presented at a conference of fertility experts. Delegates hailed it as a "remarkable milestone" for fertility treatments.

The first test tube baby, Louise Brown, was born in the United Kingdom in July 1978. However, delegates at the conference in Turkey warned couples not to use fertility treatment as an "insurance policy" if they delayed parenthood.

About 1.5 million cycles of in vitro fertilization, and similar techniques, are performed every year, resulting in 350,000 babies worldwide.

IVF success rates (based on figures for 2008)
33.1% for women under 35
27.2% for women aged 35-37
19.3% for women aged 38-39
12.5% for women aged 40-42

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