Celiac disease may be at the root of some women’s problems with infertility, Indian researchers say. While there are many more common causes of infertility, the study suggests that women who don't have a ready explanation for their failure to conceive should be screened for celiac disease, said Dr. Govind Makharia, a professor at All India institute of Medical Sciences in New Delhi. "There isn't strong evidence to say that celiac disease causes infertility, but there are many anecdotal experiences where women with infertility have conceived after being diagnosed with celiac disease and put on a gluten free diet," Makharia told Reuters Health in an e-mail

About one in 100 people have celiac disease. If they consume wheat, barley or rye, or foods that contain those grains, their immune response leads to intestinal damage, malnutrition and other problems.

Generally, women are considered infertile after one year of unsuccessfully trying to conceive, or six months if they are older than 35. The most common causes are hormonal problems that stop the ovaries from producing or releasing mature eggs. Being extremely underweight or overweight can impact fertility, as can excessive exercise, smoking, and drinking.

To explore the link between celiac disease and infertility, Makharia's research team pooled results from previously published research studies.

Women with infertility were 3.5 times more likely to have celiac disease than women who didn't have difficulty conceiving, the analysis found, based on a review of three studies including 449 women with infertility.

For women with no known cause for their infertility, the connection was even stronger. These women were six times more likely to have celiac disease, based on data from five studies including 422 women with unexplained infertility.

"Celiac disease has been claimed to be the most common cause of unexplained infertility and these results support that conclusion," said Dr. Alessio Fasano, director of the Center for Celiac Research at Massachusetts General Hospital in Boston.

Celiac disease is not always recognized right away in women with fertility issues because ob-gyns will typically send them to see an endocrinologist, to explore hormonal causes, before they consider rarer conditions such as celiac disease, said Fasano, who wasn't involved in the study.

The study findings suggest that ob-gyns should consider a blood test to rule out celiac disease before sending a woman to other specialists, he said.

"If I was an ob-gyn, I would do the screening for celiac right there in my office before I sent the woman anywhere else," Fasano said.

Typically though, doctors start looking for the cause of infertility by asking women to record what's known as their basal body temperature, a reading taken immediately after waking up each morning, for two to three months to see which days the temperature spikes to indicate ovulation. This will show whether the woman has a normal menstrual cycle, and whether she's ovulating at the same time each month, potentially helping her to plan intercourse during the point in the cycle when she's most likely to conceive.

There may also be urine and blood tests to screen for a variety of hormones involved in ovulation, as well as imaging tests to see if there are problems with the Fallopian tubes or the uterus.

While the new analysis, published in the Journal of Clinical Gastroenterology, establishes a link between celiac disease and infertility, it doesn't prove that celiac disease causes infertility, a task that has eluded scientists for decades. The researchers also said that the validity of their analysis is limited because it's based on just a handful of published studies with a small number of women.

"The issue of celiac disease as a cause of infertility has remained a debatable issue," Makharia said. "The pooling of data from all the eligible studies in this meta-analysis now brings forth reasonable evidence to support screening."