Genetic testing is sometimes advised prior to become pregnant. Usually this is done in conjunction with a visit with a medical geneticist
or a genetic counseling session. The specifics of what happens at one of these sessions depends on what your scenario happens to be.
For example, if you have a strong family history for a rare or genetic disease or if you or your partner have been diagnosed with a condition. This can be very helpful, because the counseling session can help you decide what your risks are of having a baby with this condition. Often, part of this session will involve recommendations on specific genetic testing (usually blood tests) that you or your partner may be asked to undergo to help further characterize the risk.
Another reason that genetic counseling might be indicated is if you have a history of multiple miscarriages, as this might be evidence of a genetic abnormality that is causing the miscarriages. Genetic testing could cast light on the reason for the miscarriages.
Generally speaking, genetic testing or counseling would not be recommended for all women prior to getting pregnant but it would be recommended in these situations. Some OB GYN doctors
will do basic testing for very common conditions, such as cystic fibrosis
or sickle cell, and so you may not need a specific counseling session to have these done.