The study was conducted through a lengthy online survey and involved 970 women: 329 of whom had tested postive by biopsy for celiac disease, and a control group of 641 women without the disease.
While about three-quarters of each group had become pregnant at least once, the authors found the rate of miscarriage to be significantly higher in the celiac group – slightly more than 50 percent compared to 40 percent among participants without the disease.
Also striking was that giving birth prematurely had been experienced by almost 24 percent of the celiac group, compared to 16 percent of non-celiac survey participants.
Dr. Stephanie Moleski, lead author of the study published in the April 2015 edition of the Annals of Gastroenterology*, told Allergic Living that the findings show the need for more testing. “All physicians, no matter what specialty, should be on the lookout for celiac disease,” she said.
But what’s the relationship between the condition and miscarriage or early delivery? “Pregnancy complications in celiac disease patients have been linked to vitamin and mineral deficiencies of zinc, selenium, iron and folate,” says the Philadelphia gastroenterologist, who’s an assistant professor of medicine at Thomas Jefferson University Hospital.
Q&A with Dr. Moleski
For more insights, the researcher answers Allergic Living’s questions.
Q There have been other studies to suggest a relationship between celiac disease and reproductive issues. Should women experiencing complications be given blood tests for celiac disease?
Dr. Moleski: Celiac disease affects about 1 percent of the U.S. population. The mean age of a diagnosis of celiac disease is advancing, thus more women are at a reproductive age and may not yet be diagnosed. Currently, prenatal testing includes testing for diseases that are much less common than celiac disease, for instance, syphilis. I do recommend testing for celiac disease to my patients who have had fertility problems.
Q What could doctors be watching for – so that the woman who would like to get pregnant could be tested before a complication arises?
Dr. Moleski: All physicians, no matter what specialty, should be on the lookout for celiac disease. It can present with gastrointestinal symptoms such as diarrhea, bloating or weight loss. However, only about one-quarter of patients present with these classic malabsorptive-type symptoms.
Many patients present with only one symptom, and a quarter of patients might have no gastrointestinal symptoms and only extra-intestinal symptoms such as anemia, osteopenia, chronic fatigue or arthralgia (joint pain). I think it would be appropriate to consider testing for celiac disease in patients with any of these symptoms and/or a family history of celiac disease.
Q Why would celiac disease affect a woman’s pregnancy?
Dr. Moleski: The pathogenesis of pregnancy complications in celiac patients has been linked to vitamin and mineral deficiencies of zinc, selenium, iron and folate. The inflammation which occurs in the small intestines with untreated celiac disease leads to malabsorption of these vitamins, which can then disrupt hormones and lead to pregnancy complications.
It has also been suggested that placental tTG (an enzyme linked to celiac disease) may be bound by a maternal antibody to tTG, which may adversely affect placental function.
Q Did the women in your study with confirmed celiac disease experience pregnancy complications before diagnosis and before starting a strict gluten-free diet?
Dr. Moleski: Most of the women did experience complications before starting a gluten-free diet. Other studies have shown that once women are on a gluten-free diet, their pregnancy outcomes normalize.
An Italian study (Ciacci et al) found that women who were undiagnosed with celiac disease and not on a gluten-free diet had a higher risk of miscarriage compared to women with celiac disease who were already on the diet.
This makes sense because when patients are doing well with a gluten-free diet, the small intestine heals, and vitamins and minerals are then absorbed appropriately and patients are healthier.
Q There was a large study out of England in December 2014 that did not find an increased risk of infertility in women with celiac disease. The results of fertility and pregnancy issues studies are varied. What will be needed to once and for all resolve such questions?
Dr. Moleski: The research on celiac disease and pregnancy has been mixed over the years. The recent large study from England did not find an increased risk of infertility (although rates of infertility were 41 percent higher among women diagnosed with celiac disease when they were 25 to 29 – an age when many women are seeking pregnancy).
Our study did not show an increase of infertility either. It did, however, show an increase in miscarriages and pre-term delivery. More large prospective trials looking at pregnancy complications and celiac disease are needed to better understand the connection.
*Dr. Moleski and her colleagues noted some limitations with their new study, including that information was gathered through online questionnaires and the fact that the women with celiac disease weren’t screened for other possible medical explanations for pregnancy complications.