Surrogate mothers face greater risk of complications during pregnancy, study finds

Women who act as surrogates are at greater risk of health problems than women who carry their own children, research shows.

The use of surrogate mothers, or ‘gestational carriers’, has increased dramatically in recent years, with figures for England and Wales This shows that the number of parentage orders, in which the legal parentage of the surrogate mother is transferred, has increased from 117 in 2011 to 413 in 2020.

A study based on data from Canada suggests that surrogate mothers are more likely to experience complications, including severe postpartum hemorrhage and severe preeclampsia, than women who conceive naturally or through IVF. Babies born to surrogates were more likely to be born prematurely, though they were not more likely to have serious neonatal complications.

Experts say the findings highlight the need for better prenatal care for surrogate mothers and the establishment of strict criteria and rules for women who wish to take on such a role.

Dr. Maria Velez, the study’s lead author, from McGill University in Canada, said it is important to inform expectant parents and surrogates about possible complications.

“Those complications are important for (carriers),” she said. “But they also impact the intended parents, (and) the physician who is taking care of that patient.”

Writing in the diary Annals of Internal MedicineVelez and colleagues report how they used the Better Outcomes Registry & Network (Born) database to examine the occurrence of complications among 863,017 singleton births in Ontario that occurred between 2012 and 2021.

Of these births, the team said, 806 babies were born to surrogates – typically receiving an embryo from the intended parents – 846,124 were the result of unassisted conception and 16,087 were the result of IVF.

The team found that the rate of serious maternal health complications was 7.8% in surrogates, 2.3% in the unassisted conception group, and 4.3% in pregnancies involving IVF.

While the researchers found that surrogate mothers were more likely to have certain characteristics, such as having given birth before, living in a lower-income area, being obese and having high blood pressure, such factors do not appear to fully explain the results.

When we take into account factors such as age, income level, number of previous births, obesity, smoking and high blood pressure, The team found that the risk of major postpartum hemorrhage was 2.9 times higher for surrogate mothers compared with women who conceived unassisted, while the risk of giving birth before 37 weeks was 1.79 times higher. Such risks were also higher, albeit to a lesser extent, for surrogate mothers compared with women who underwent IVF.

“There may be other mechanisms, including perhaps an immunological mechanism, that could be involved in this increased risk (for carriers),” Velez said.

Jackie Leach Scully, a professor of bioethics at the University of New South Wales who was not involved in the study, noted that the study had limitations. For example, it only studied a small group of surrogate mothers, and these women may have previously had healthy babies without health problems during pregnancy.

“What this paper does highlight, however, is that we actually know relatively little about the specific risks of harm to the woman who acts as a surrogate, or to the baby, in surrogacy,” she said, adding that while a surrogate mother should ideally be healthy and have a low risk of complications, in practice this was not always the case.

“This raises a number of ethical questions, first of all about the potential exploitation of women who act as gestational carriers and who are effectively bearing the risks of the pregnancy on behalf of someone else,” she said.

“Second, the paucity of accurate data on the risks and outcomes of surrogacy should really make us question how seriously women’s health, as opposed to the health of the fetus or baby, is taken. The neglect of women’s health throughout the history of medicine is well known and may be exacerbated in the context of surrogacy, where the role of the surrogate mother is socially unclear.”