Health Canada warns of possible false positives in pregnancy test recall

Health Canada has issued a safety notice and recall for HCG one-step pregnancy tests manufactured by Innovacon Inc. due to potential false positive results. The issue arises when the product detects low levels of HCG below the established sensitivity threshold, leading to incorrect positive outcomes in individuals who are not pregnant.

The agency emphasized that the package insert will be updated to acknowledge that low HCG levels can occur during perimenopause, urging customers to consider this fact when interpreting the test results.

The rapid response tests are designed for early pregnancy detection by identifying human chorionic gonadotropin (HCG) in urine, a hormone produced by the placenta after a fertilized egg implants in the uterus. HCG levels typically double every two to three days during early pregnancy. Waiting a day or two after a missed period to take the test increases the likelihood of a positive result, as the Mayo Clinic explains.

Several factors can affect the accuracy of home pregnancy tests, including false positives. A false positive may occur if a miscarriage happens shortly after the fertilized egg attaches to the uterine lining or if a person takes a pregnancy test shortly after using fertility medicine containing HCG. The Mayo Clinic highlights that elevated HCG levels can also result from ovarian issues or menopause, contributing to false positive test results.

Irregular menstrual cycles can further complicate the interpretation of pregnancy test outcomes, as they make it difficult to predict when a period should begin.

Home pregnancy tests vary in sensitivity, with more sensitive tests requiring lower HCG levels in urine to produce a positive result. However, false negatives are more likely when individuals take the test too early. The most accurate results typically occur on the first day after a missed period. Recalls of pregnancy tests in Canada have occurred previously due to unreliable results or packaging issues.