TUESDAY, Sept. 24, 2024 (HealthDay News) -- Surrogate moms have a higher risk of pregnancy complications than other pregnant women, a new study finds.

About 8% of surrogate mothers developed a severe complication like high blood pressure or serious bleeding during delivery, Canadian researchers report.

By comparison, only 2% of women who conceive naturally and 4% of women who conceive via IVF develop similar complications, researchers found.

This is one of the first large-scale studies to compare outcomes between the three different types of pregnancy, they noted.

“Clinicians involved in the care of individuals and couples who need a gestational carrier to build their family should counsel their patients and the gestational carriers about the potential risk during pregnancy and early postpartum,” said lead researcher Dr. Maria Velez, an adjunct scientist with the Institute for Clinical Evaluative Services in Kingston, Ontario.

For the study, researchers analyzed data on more than 863,000 births in Ontario, Canada, between 2012 and 2021. Nearly 98% of pregnancies involved natural conception, compared with 1.8% conception with IVF and 0.1% a surrogate.

Overall risk of complications is higher for surrogates, researchers found, and surrogates have a specifically higher risk of high blood pressure and bleeding after delivery.

Surrogates were also more likely to have a preterm birth, results show.

The new study was published Sept. 23 in the Annals of Internal Medicine.

Further study is needed to figure out why surrogate moms are at greater risk for complications, researchers said.

“There are guidelines about the eligibility criteria to minimize the risk of pregnancy complications among gestational carriers,” Velez said in an institute news release. “However, these guidelines are not always strictly followed.”

More information

Yale Medicine has more on surrogacy.

SOURCE: Institute for Clinical Evaluative Services, news release, Sept. 23, 2024