There are early pregnancy tests, personal blood pressure monitors and even home cholesterol screens. So why not do-it-yourself D-N-A tests?

Medical experts have become increasingly concerned in recent years about the availability of home genomics tests. More than twenty companies market tests that… for a few hundred to a few thousand dollars… will determine your baby’s father, predict your baby’s sex or estimate your risk for developing diseases like cancer, diabetes and blindness.

Some of the tests are designed for use and interpretation at home, while others require customers to mail in samples of hair, blood, urine or even chewed gum. Companies sometimes charge more for personal interpretation of the results by a genetic counselor.

But medical experts warn that many home D-N-A tests haven’t been validated in clinical trials and their accuracy is highly variable. Incorrect diagnoses can cause undue anxiety and patients may be unsure how to proceed without guidance from a licensed health-care professional.

Still, many consumers opt for at-home testing for privacy reasons. Home testing prevents insurance companies from finding out about potential medical conditions. And some mothers would rather conduct paternity testing without alerting the baby’s suspected father by sending in hair samples from the man’s hairbrush.

So if you’re concerned about your genetic risk for developing a disease, think twice before shelling out money for at-home testing. Until mail-order tests become more reliable, don’t take chances with your health… ask your health-care provider for more information.