Babies of mothers with endometriosis face higher birth defect risk: study – National

New research has found that mothers with endometriosis face a slightly increased risk of giving birth to babies with birth defects.

A newly released study by the Canadian Medical Association Journal (CMAJ) analyzed data of more than 1.4 million births in Ontario between April 7, 2006, and March 31, 2021, with 33,619 babies being born to people who had endometriosis.

Of that number, 2,120 babies had a congenital anomaly, representing a 6.3 per cent rate.

Compared to babies born to people without endometriosis, 77,094 had a congenital anomaly, representing a 5.4 per cent rate. The study concluded that “endometriosis in the patient was independently associated with a higher risk of any congenital anomaly.”

“I think what really comes out of this is it’s just so important to investigate and to provide the resources for researchers to look at these issues,” said Dr. Nicholas Leyland, president-elect of the Society of Obstetricians and Gynaecologists of Canada (SOGC).

“This study highlights a good way of looking at these particular diseases to be able to determine how best we can intervene or whether or not there’s anything we can do to prevent these congenital anomalies, a better understanding of inflammation and how it affects pregnancy.”

The study found that “specific anomalies with the highest associated risks included unspecified cleft palate, hypospadias and pulmonary artery stenosis.”

Leyland said that something about the endometriosis and possibly infertility treatment “may be aligned” with the creation of “rare but significant congenital anomalies.” 

He also stated that while the increase in congenital anomalies found from the study is notable, it can also be drawn to the nature of endometriosis, which he states is inflammation.

“During pregnancy, it [inflammation] potentially has the influence on the development of organogenesis or as the embryo and the fetus develops, development of the different organ systems,” Leyland said.

President of Endometriosis Canada Violeta Kondovski said that the results of the study “aren’t that shocking to the endometriosis community,” because “many people with endometriosis also have connective tissue disorders, which can be linked to some congenital anomalies.”

According to Endometriosis Network Canada, the condition affects at least one in 10 women in Canada, with almost two million Canadians estimated to have endometriosis.

However, Kondovski said that number could be much higher.

“It could a lot more [people] than we think, we just don’t know because a lot of people don’t the symptoms. They could be either asymptomatic, or they just think their symptoms are normal and they have to deal with it,” she said.

“Some people are taught by their families that some people have tougher periods and it’s just like that for certain people, or that maybe the women in their family had more painful periods and that they just have to deal with. And unfortunately, that’s passed down so often that it’s taking forever for anyone to get diagnosed because they don’t know what’s wrong.”

Both Kondovski and Leyland also stressed that the findings of the study are not meant to scare expecting mothers, with Kondovski saying the study is “showing a light on it so that everyone is paying attention to it.”

“In terms of counselling women with endometriosis, we wouldn’t want to frighten them,” said Leyland.

“But we would say that we’re going to do the same testing and screening that’s available to us now to pick up issues as they arise and then deal with them as necessary when the baby is born if it is an issue that requires treatments such as hypospadias, cleft lip and palate.”

While research is still in the early stages, an April 2026 study from Oxford University uncovered a potential non-invasive scan trial that was able to correctly detect the presence or absence of endometriosis in 16 out of 19 women.

It also found that the specialized CT scans are “accurately detecting endometriotic lesions” that is often “missed by conventional imaging methods.”

“There is an urgent need for advancement in non-invasive or minimally invasive imaging of endometriosis, particularly superficial peritoneal endometriosis, given the current reliance on invasive procedures for an accurate diagnosis,” the study reads.

“The DETECT study describes, for the first time to our knowledge, a minimally invasive diagnostic technique.”

Kondovski hopes that the door is beginning to open for increased funding for future research on endometriosis and its implications.

“We know that it [endometriosis] is already a full body condition, that it that has a greater chance of being passed down through our children,” she said. “We just don’t have all the learnings because there hasn’t been very much research.”

“It’s [endometriosis] not just bad periods. It damages our organs, you [can] lose organs, we lose our fertility, we have miscarriages because of it, it just affects our lives so much. We hope something changes soon.”

&copy 2026 Global News, a division of Corus Entertainment Inc.