One in five women conceive naturally after having a baby through IVF, scientists have found, suggesting fertility techniques may actually boost natural conception.
Experts from University College London said women should be made aware that the chances of a natural pregnancy are relatively high after fertility treatment.
A study of more than 5,000 women found that a significant number (about 20 percent) who had difficulty conceiving became pregnant without help after fertility treatment.
While scientists don’t know what causes the effect, they speculated that stimulation of the ovaries by IVF cycles might improve the overall function of the ovaries.
Hormonal changes that occur during pregnancy can also help women conceive naturally, while women may simply feel less stressed after a successful delivery. Stress is a known factor that causes infertility.
Lead author, Dr Annette Thwaites, said: “Our findings suggest that natural pregnancy after delivery through IVF is far from rare.
“This contrasts with the widely held beliefs – by women and health professionals – and often expressed in the media, that it is an unlikely event.”
Dr. Thwaites said reduced stress may be a factor.
“The importance of psychological factors on fertility is widely recognized. There are many theories about this. It is biologically possible that ovarian stimulation from IVF cycles may improve ovarian function.
The team says the findings are important because many women may not realize they can conceive naturally after fertility treatment.
Get pregnant again quickly
This can lead to them getting pregnant again soon or not being ready yet.
Shema Tariq, 47, a doctor and academic from London, was diagnosed with low ovarian reserve and said her chances of getting pregnant without IVF were almost zero.
It took six rounds of IVF before she gave birth to her son in 2019, yet she conceived naturally within eight months of giving birth.
“My GP told me about contraception shortly after he was born, but we both laughed and agreed it was irrelevant.
“It never occurred to me that I could get pregnant (despite being a sexual health practitioner). I was 43 and I had been told my chance of conceiving naturally was less than one percent.
“Eight months later I was unexpectedly and naturally pregnant with our daughter. She was the most wonderful surprise, but when we first found out, I felt overwhelmed and unprepared for another pregnancy.
“Had I known that one in five women conceive naturally after IVF, I would have used birth control until I was ready both emotionally and physically.”
IVF was first used in 1978 and now more than 10 million babies have been born worldwide using the treatment – equivalent to between one percent and six percent of all babies born each year in the developed world by 2020.
In the UK, more than 50,000 patients undergo IVF treatment each year.
The finding that a significant number of women are able to conceive naturally after fertility treatment may also help couples avoid spending unnecessary money on treatment.
Dr. Thwaites added, “Knowing what is possible would enable women to plan their families and make informed choices regarding further fertility treatments and/or contraception.”
The research is published in the journal Human Reproduction.