Here we share links to studies on surrogacy and other relevant research.

The UK academics leading surrogacy research in the UK are all pro-surrogacy:

Studies on Medical Risks

There are several recent studies that show risks for surrogate mothers are higher than that for non-surrogacy pregnancies.

A large population study from Canada looked at over 863,000 births between 2012-2021 and concluded that the medical risks in surrogacy are x3. This aligns with the meta analysis below:

(With thanks to @DeWallenDaily for this infographic.)

A 2022 study interviewed 96 surrogate mothers and found:

“Complications or adverse effects were defined as the following: high blood pres
sure during pregnancy, preeclampsia or eclampsia, gestational diabetes, hemorrhage, infection related to pregnancy, pre-term labor, hyperemesis gravidarum, anemia, ectopic pregnancy, placenta previa, placental abruption, ovarian cysts, miscarriage, postpartum depression, and high blood pressure in the postpartum period. Not all surrogate pregnancies resulted in complications or adverse effects. The most complications that one woman faced during her surrogate pregnancy, that she did not experience during her non-surrogate pregnancy or pregnancies, was seven.”

SOS GPA in Canada issued this statement:

“This large-scale study based in Ontario demonstrates strongly that surrogacy pregnancies are the riskiest pregnancies of all, even when there are so-called altruistic. The fact that the Canadian health care system is of good quality and publicly funded does not mitigate the fact that surrogate mothers are exposed to 3 times the risk of severe maternal morbidity compared to mothers with unassisted conception. Our government has left it to the surrogacy and fertility industry to inform potential surrogate mothers of these risks.

The great paradox is that most surrogate mothers don’t need assisted conception to begin with. Assisted conception is mostly used to secure legal parentage for the client. As the researcher points out: “Severe Maternal morbidity comprises an array of conditions as life-saving procedures that are along the continuum of maternal death”. While we are relieved that the surrogate mothers in the study had access to the life-saving procedure provided by the health care system of Ontario (funded by taxpayers), it is statistically plausible that, in the future, a Canadian surrogate mother will die while delivering a child for surrogacy clients. Sadly, neither the Ontario or the Québec governments mandate surrogacy clients to purchase life insurance for the surrogate mother and her family.

Finally, in all surrogacy situations, the child experience a loss equivalent to the death of his mother, as he is brutally separated from her in order to be given to the surrogacy clients. SOS GPA aims to provide accurate and fact-checked information to surrogate mothers and prospective parents in Québec, as well as health professionals and the media. We hope that by being given accurate information about the multifactorial harms of surrogacy, the Canadian citizens will eventually stop from engaging in it in all its forms, altruistic or commercial.”

Studies on Post Natal Depression

Erica Fuchs studied post natal depression in surrogate mothers. From 222 completed surveys she found that there was a significant increase of depression in traditional surrogate mothers (where the woman conceives with her eggs) compared to gestational surrogate mothers. A score of 16 or higher was noted at 37.5% for these women compared to 4.0% for those the surrogate mothers who had egg donor conceived pregnancy which carries increased medical risks.

Related studies

We know as a society that babies need their mothers and in psychology this is described as maternal bonding or attachment theory, beyond this there are known physiological connections:

Cell Swap

Maternal fetal microchimerism is the name given to the process by which mother and baby ‘swap cells’ in utero. These cells from the and baby stay in her body after pregnancy and have been detected decades later. We have evidence that a baby prefers their mother’s face, they know her voice, smell and find her heartbeat comforting and this is why Skin to Skin is recommended (it is thought to be largely ineffectual when done with fathers).

Diet

In 2024, Researchers found that a mother’s diet can have a small impact on her baby’s developing facial features . They wrote in the journal Nature Communications: “We found that modulation of the level of protein in the maternal diet regulates mTORC1 activity, resulting in subtle but distinct changes in the craniofacial shape of the embryos.”

Psychologists Durham’s Fetal Neonatal Research Lab led a study which showed the baby reacting to certain foods in utero. 4D ultrasound scans of 100 pregnant women showed how the fetuses reacted to either carrot or kale capsules. The results show the first direct evidence that babies react differently to various smells and tastes while in the womb by looking at their facial expressions. Other studies have suggested that babies can taste and smell in the womb, but this was the first study to see these reactions before birth.

For mothers, it is known that as a physical, biological process a woman’s body is affected in a number of ways throughout pregnancy and after birth but the results from an animal study in 2023 it is thought that pregnancy can permanently rewire the brain through pregnancy hormones estradiol and progesterone.

“What’s fascinating is that this switch doesn’t happen at birth – the brain is preparing much earlier for this big life change.” ~ Dr Jonny Kohl, Francis Crick Institute.

Maternal Separation and Social Behaviours

Along with the study on developmental delays and immunity dysregulation it is thought that there can be social long term impacts as a result of maternal separation. An animal study researched the long-term effects of maternal separation on social interaction behavior and concluded that:

“Variations in qualities of mother–infant relationships among humans thus appear to have deep biological roots in the form of their capacity to shape children’s psychological and biological responses to their environment — effects that extend into adulthood,” ~ Myron Hofer, psychiatrist