ICSI (intra-cytoplasmic sperm injection)

This is IVF in which a single sperm is injected into the body of the egg. As ICSI bypasses even more barriers than conventional IVF, it has allowed men who previously had little chance of fathering their own child to do so. The success rate is at least as good as for ordinary IVF – around one in four at the best clinics.

There were worries that this technique could lead to more abnormalities in ICSI babies. The current medical view is that although there's been a slight increase in sex chromosomal abnormalities in ICSI babies, the procedure is generally thought to be safe.