Co-IVF pregnancies may increase risk of serious complications, study suggests

Women using their partner’s egg in co-IVF treatment may face higher risks of complications for themselves and their babies, research suggests.

The review of more than 9,000 patients found increased risks of pre-eclampsia and gestational diabetes, alongside lower birth weights, despite higher live birth rates.

Co-IVF, or reciprocal IVF, lets women in same-sex relationships share the pregnancy journey: one partner provides the egg, while the other carries the baby created with donor sperm.

Elizabeth Choong, first author and an undergraduate student in medicine at the University of Leeds, said: “Numbers of same-sex female couples choosing co-IVF are increasing, so it is vitally important that the risks they face in undergoing this procedure are clearly explained from the outset.

“We hope our research can help keep same-sex couples fully informed before they make any family planning decisions.”

Researchers from King’s College London, Anglia Ruskin University and the University of Leeds analysed five studies comparing co-IVF with conventional IVF, where one partner uses her own egg and donor sperm.

The analysis revealed potential increased risks of pre-eclampsia – a condition that causes high blood pressure and protein in urine during pregnancy – and gestational diabetes, which develops during pregnancy and usually disappears after birth.

IVF cycles among same-sex female couples in the UK rose almost seven-fold between 2008 and 2018, from 320 to 2,151.

Co-IVF is not routinely offered on the NHS, but availability can depend on local policies.

Until late 2024, women undergoing co-IVF faced enhanced screening for hepatitis B, hepatitis C and rubella, costing up to £1,000.

This requirement has now been removed.

Professor Susan Bewley, co-lead of the study and emeritus professor of obstetrics and women’s health at King’s College London, said: “Rates of co-IVF have increased dramatically in the UK.

“It’s important that couples going into the process are aware of potential complications that might happen because the baby is genetically unrelated to the pregnant woman.

“All women deserve full, unbiased information about the extra risks to mother and baby associated with carrying a donor-egg pregnancy – so they can make their own decisions about whether the risk outweighs the benefit.”

The researchers said “ethical considerations must be made to avoid harm whilst respecting patient autonomy and informed consent” when it comes to co-IVF.

While the findings were described as “worrying”, the researchers emphasised that larger studies are needed to confirm them.

Catherine Meads, professor of health at Anglia Ruskin University, said: “These worrying preliminary findings need to be investigated in a much larger-scale study to determine the precise additional risks when women opt to undertake a pregnancy with a donated egg.”

The complications may occur because the pregnant woman’s immune system recognises the embryo as genetically different, similar to risks seen in traditional donor-egg pregnancies.

This immune response can increase the likelihood of pregnancy complications.