A fertility center in Illinois says it will soon begin giving couples a test for fertility to determine if they have ovarian cancer.

Health Canada said Friday that it will issue a warning letter to Canadian doctors who offer fertility tests, saying they could be linked to the cancer.

The warning letter comes a day after Health Canada issued a similar warning to doctors in the U.S.

A health ministry spokesperson said the warning is not an emergency and that doctors are still free to offer a test.

The Canadian Cancer Society says that although its research shows that many couples in Canada are at low risk for ovarian cancer, the cancer is still more common in the United States.

The society said its numbers are much higher.