Around one in five women conceive naturally after having had a baby using fertility treatment such as IVF, according to research.

A review of previous studies has shown 20% of women who sought assisted conception for their first child are able to become pregnant naturally within three years.

The researchers said their findings, published in the journal Human Reproduction, highlight that getting pregnant naturally after IVF is not as unusual as thought.

Lead author, Dr Annette Thwaites, of University College London’s EGA Institute for Women’s Health, said: “Our findings suggest that natural pregnancy after having a baby by IVF is far from rare.

“This is 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.”

For the study, the researchers analysed data from 11 studies of over 5,000 women around the world between 1980 and 2021, including 1,160 from the UK.

The research also included a report published by Dr Thwaites which included interviews of 22 UK women who experienced natural pregnancy after fertility treatment.

The team said a vast majority of participants in the studies had subfertility – where conceiving takes longer than typically expected.

It means not all women seeking and undergoing fertility treatment are absolutely or permanently infertile, the researchers added.

A small number of participants underwent the IVF procedure due to reasons not related to infertility, such as being in a same-sex relationship, being a single parent or being a surrogate.

With more than 10 million babies born worldwide via IVF, the researchers said it is important for those who have had successful treatment to know how likely they are to conceive naturally afterwards.

Dr Thwaites said: “Knowing what is possible would empower women to plan their families and make informed choices regarding further fertility treatment and/or contraception.”

Shema Tariq, a doctor and academic from London, who has two children aged three and four, was diagnosed with low ovarian reserve and told that her chances of conceiving without IVF were almost zero.

She says: “It took six rounds of IVF to conceive our son, who was born in 2018.

“My GP briefly mentioned contraception to me after he was born, but we both laughed and agreed that it wasn’t relevant.”

Ms Taris, 43, continued: “Eight months later I was unexpectedly, and naturally, pregnant with our daughter.

“She has been the most wonderful surprise, but when we first found out I felt overwhelmed and unprepared for another pregnancy.

“If I’d known that one-in-five women conceive naturally after IVF I’d have used contraception until I was ready both emotionally and physically.”