SMA carrier testing requires a blood sample that can be drawn from the couple in a doctor's office. Ideally this should be done before a couple conceives, as this gives them the most reproductive options should they be at risk of having a baby with SMA. However, many couples undergo carrier testing early in pregnancy.
Your doctor ships the blood specimen to a specialized laboratory, such as Athena Diagnostics, where it undergoes analysis of DNA using highly sophisticated technologies. Within a week or ten days (at Athena Diagnostics), your doctor receives the results of your tests.
The results will tell your doctor with a high degree of certainty whether you and your husband are SMA carriers. If you are carriers, you will be counseled by your doctor or a genetic counselor regarding the limitations of testing (up to 10% of SMA carriers cannot be detected with current tests), the significance of your results, and your options.
Because the American College of Medical Genetics guidelines recommending SMA carrier testing for all individuals regardless of race or ethnicity are relatively new, you may want to ask your doctor to order this test if he or she does not suggest it.