Previously undocumented effect of IVF uncovered; helps 1-in-5 women conceive naturally second time around

Every year, around the world, thousands of people undergo fertility treatments to have children. Now, a new study has concluded that one in five women who undergo such treatments are likely to conceive their second child naturally soon after.

University College London's study as per News Medical is the first of its kind. It analysed data from 11 studies that consisted of over 5,000 women worldwide. Data from between the years 1980 and 2021 was used to calculate how common it is for women to naturally fall pregnant after having conceived a baby via fertility treatment.

It found that at least one in five women or about 20 per cent conceived naturally after fertility treatments. Most women reported a natural pregnancy within three years of the treatment which in most cases was in vitro fertilisation (IVF).

As per the News Medical report, even after taking into account the different types and outcomes of fertility and the length of the follow-up, this one-in-five figure remained unchanged in most cases.

As per the study, infertility is defined as a failure to conceive even after 12 months or more of regular unprotected sex. 

Estimates show that at least one in seven heterosexual couples suffer from infertility.

However, as per the study, "it is important to recognise that women seeking and undergoing fertility treatment are not absolutely nor permanently infertile. Over 80 per cent of couples in the general population will conceive naturally within one year; of those who do not conceive in the first year, about half will go on to do so in the second year."

It is not just infertile heterosexual couples that opt for fertility treatments. Single women, homosexual couples, surrogates etc., also undergo fertility treatments.

People undergo IVF for a "wide range of causes, including ovulatory disorders, tubal factors, uterine factors, male factors, joint subfertility, and unexplained subfertility."

BBC reports that University College London's Dr Annette Thwaites, lead author of the study, said that their findings suggest that "natural pregnancy after having a baby by IVF is far from rare."

As per Thwaites, their findings are in "contrast with widely held views - by women and health professionals - and those commonly expressed in the media, that it is a highly unlikely event."

Clinical Embryologist Dr Marta Jansa Perez, of the British Fertility Society, remarked that "this study highlights the importance of giving patients accurate information about their chances of conception at any point, in particular after giving birth to an IVF baby."

"It is good news that such a high proportion of patients can conceive naturally after IVF, but people should be aware that in cases where the age of the woman is a factor for the initial failure to conceive or there is severe male factor infertility, it would be advisable to seek treatment for a second child sooner rather than later."