Women with doctor-diagnosed celiac disease are more likely to miscarry or deliver preterm than women with no history of the condition, according to a small U.S. study. 

Researchers say that women experiencing miscarriages or preterm deliveries should be checked for undiagnosed celiac.

While there are many more common causes of pregnancy complications, women who don't know why they can't conceive or carry a baby to term should find out if they have celiac disease, said lead study author Dr. Stephanie Moleski, a researcher at Thomas Jefferson University Hospital in Philadelphia.

"Miscarriage in celiac disease patients has been linked to vitamin deficiencies of zinc, selenium, iron and folate," Moleski said by email. "When I see patients who have had fertility or pregnancy complications I feel it is appropriate to consider testing for celiac disease."

Moleski and colleagues surveyed 329 women with biopsies confirming celiac disease as well as 641 women without the condition. Using online questionnaires, the researchers asked reproductive health questions ranging from the age the women started menstruating to the number of pregnancies they experienced and the birth circumstances for any babies delivered.

There wasn't any difference in the number of women with or without celiac disease who got pregnant at least once, but the women with celiac disease were less likely to give birth, the study found.

Women with celiac disease had miscarriages about half the time, compared with 40% of the time among the other women in the study. About one in four women with celiac disease had premature deliveries, compared with about 16% of the other women.

Limitations of the study, according to the April 15 Annals of Gastroenterology online report, include its reliance on the online questionnaires, which depend on patients having accurate recollections, and which didn't verify whether participants had other health conditions that might lead to miscarriages or preterm deliveries.

Restricting the celiac group to women diagnosed with a biopsy also means that some women in the non-celiac group might have had undiagnosed celiac, which would skew the results.

While previous research has linked celiac diseases to fertility and pregnancy problems, the exact reason the condition leads to miscarriages and premature babies is unknown, Dr. Govind Makharia, a professor of gastroenterology and nutrition at All India Institute of Medical Sciences in New Delhi, said by email.

"At present, the association between infertility, miscarriage, preterm babies and celiac disease is conjectural and not definitive," said Makharia, who wasn't involved in the study. Celiac might be a cause, but other causes are more likely.

"However, there may not be any harm in screening for celiac disease," Makharia said.