In-vitro fertilisation, known as IVF, is a medical procedure in which a woman has an already-fertilised egg inserted into her womb to become pregnant.
It is used when couples are unable to conceive naturally, and a sperm and egg are removed from their bodies and combined in a laboratory before the embryo is inserted into the woman.
Once the embryo is in the womb, the pregnancy should continue as normal.
The procedure can be done using eggs and sperm from a couple or those from donors.
Guidelines from the National Institute for Health and Care Excellence (NICE) recommends that IVF should be offered on the NHS to women under 43 who have been trying to conceive through regular unprotected sex for two years.
People can also pay for IVF privately, which costs an average of £3,348 for a single cycle, according to figures published in January 2018, and there is no guarantee of success.
The NHS says success rates for women under 35 are about 29 per cent, with the chance of a successful cycle reducing as they age.
Around eight million babies are thought to have been born due to IVF since the first ever case, British woman Louise Brown, was born in 1978.
Chances of success
The success rate of IVF depends on the age of the woman undergoing treatment, as well as the cause of the infertility (if it’s known).
Younger women are more likely to have a successful pregnancy.
IVF isn’t usually recommended for women over the age of 42 because the chances of a successful pregnancy are thought to be too low.
Between 2014 and 2016 the percentage of IVF treatments that resulted in a live birth was:
29 per cent for women under 35
23 per cent for women aged 35 to 37
15 per cent for women aged 38 to 39
9 per cent for women aged 40 to 42
3 per cent for women aged 43 to 44
2 per cent for women aged over 44
