Untreated Celiac Disease in Mothers Linked with Birth Defects
By Van Waffle
The first study of its kind in North America has found an increased risk for birth defects in children of women with active, untreated celiac disease. It emphasizes the need for pregnant women at risk to get screened for celiac disease, and for those diagnosed to maintain a gluten-free diet throughout pregnancy. For women with celiac disease on a controlled gluten-free diet, there is no greater risk for birth defects than in the general population.
The study included 2.2 million infants born in Quebec, Canada, between 1989 and 2016; 125,081 had birth defects. Among 2,238 infants whose mothers had active celiac disease, the risk of heart defects was 1.58 times higher, while the risk of urinary defects was 1.56 times higher. Risk was greater for women hospitalized at least twice with celiac disease as a primary cause, and for women who were not diagnosed until after giving birth. The risk for heart defects was also higher before 2000 when the advent of better blood tests allowed celiac disease to be diagnosed more easily.
“We're paying particular attention to conditions that can affect absorption or otherwise impair the gastrointestinal system in women.”
The data came to light during a Canada-wide investigation of causes for birth defects, says lead researcher Nathalie Auger, M.D., Physician-Epidemiologist at University of Montreal Hospital Research Centre, Quebec, Canada; “We’re paying particular attention to conditions that can affect absorption or otherwise impair the gastrointestinal system in women,” conditions that reduce nutrients available to the developing fetus.
“In Quebec we have great data on pregnant women beginning from 1989. It’s possible for us to match the pregnant women with their newborns, and we can identify any birth defects in the newborns at the time of birth. The great thing about our data is that the women can be tracked over time,” says Auger.
Amelie Therrien, M.D., a clinical and research fellow at the Celiac Center, Beth Israel Deaconess Medical Center, Boston, who previously studied in Montreal and collaborated with Auger on the study, explains that hospitalizations for celiac patients might have been more common in Quebec than elsewhere in Canada, because access to primary physicians or gastroenterologists was difficult in some communities at the time. Since wait lists for tests were long, patients going to emergency with symptoms like diarrhea and abdominal pain were often admitted to a hospital to accelerate their investigations.
“But to me, these women still had a more severe presentation of their celiac disease than others who are eventually diagnosed as outpatients,” Therrien says.
The study could not provide a precise explanation for the increased risk, though it may relate to nutritional deficiency in the mother due to inflammation, she says. However, the data was controlled for other maternal health conditions such as diabetes and hypertension known to impact pregnancy. While this only shows there is a correlation, not a cause-and-effect relationship between celiac disease and birth defects, evidence for a link is strong.
"Women with well-treated celiac disease likely do not have an increased risk of birth defects based upon the results from this data set.”
Dawn Adams, M.D., Assistant Professor and Medical Director of the Center for Human Nutrition, Department of Gastroenterology, Hepatology and Nutrition, Vanderbilt University Medical Center, Nashville, Tennessee, who was not involved in the study, notes the study’s strength is a large number of infants, “in a well identified cohort with a public health system that allows broad data capture,” although a hind-sight analysis of health records will likely overlook or misidentify illnesses in some patients.
“The risk ratio for birth defects is only significant in women with significant celiac disease that have required hospitalization,” says Adams. “What I take away from this is early identification and treatment of disease is important. Women with well-treated celiac disease likely do not have an increased risk of birth defects based upon the results from this data set.”
Therrien urges women with a family history or symptoms of celiac disease to get tested before pregnancy. She points out that active celiac disease can also cause infertility and miscarriage. She also highlights the necessity of maintaining a gluten-free diet through pregnancy to ensure good nutrition for mother and fetus and reduce the risk of complications.