IVF is increasingly being used to treat a range of fertility problems outside of that which it was originally developed for and this could be risky for both mothers and children, experts have warned.

With IVF (in vitro fertilisation), a woman's eggs are fertilised with sperm outside the body in a test tube - resulting in an embryo - and then placed back inside her womb. The first IVF baby was born in the UK in 1978 and since then, more than four million children have been conceived worldwide using this treatment.

According to a group of international fertility experts, IVF was originally developed for women with disorders of the fallopian tubes and severe male infertility. However, in recent years, it has been used in the treatment of a wider range of fertility problems, including unexplained fertility.

Unexplained fertility accounts for almost one in three cases of couples presenting for IVF. However, according to the experts, many of these couples will conceive naturally if they are not treated immediately. In fact, research indicates that a significant number of couples conceive naturally, despite being affected by unexplained infertility for the previous two to three years.

The experts believe that the evidence for using IVF in certain cases is weak and they question whether the procedure is as effective in these cases. As a result, they believe ‘there should be caution about using IVF when the benefit is uncertain or the chances of natural conception are still reasonable'.

They also warned about the dangers associated with IVF for those involved. Multiple pregnancies are more likely with this kind of treatment and this can lead to complications for both mother and babies.

However, even single babies born as a result of IVF have been shown to have worse health outcomes than those conceived naturally. For example, otherwise healthy children born via IVF may have issues such as higher blood pressure and higher glucose levels than children conceived naturally.

The experts believe that the lack of quality evidence on who should have IVF needs to be addressed.

"As a society, we face a choice. We can continue to offer early, non-evidence based access to IVF to couples with fertility problems or follow a more challenging path to prove interventions are effective and safe and to optimise the IVF procedure. We owe it to all subfertile couples and their potential children to use IVF judiciously and to ensure that we are first doing no harm," commented lead author, Dr Esme Kamphuis of the University of Amsterdam.

The experts made their comments in the British Medical Journal.