With new developments in genetic testing, there are now screening tests for people before conceiving a child that will identify recessive genes linked to genetic disorders. I’m guessing that every day there are new advances in this field, and different groups offering this type of screening.
It appears these tests cannot be performed on your own, I think you have to work through your health care provider or a genetic counselor. There are many recommendations from the medical community that genetic test is best understood when reviewed with a doctor or genetic counselor, reviewing test results independent of a medical analysis can be misleading. The most detailed information I have found so far on testing is from the Merk website.
Update December 7, 2011:
Today’s local NPR station has an interesting article about testing a fetus for Down Syndrome in the first trimester using a new non-invasive DNA test.