It is not certain that any test could ensure your child is going to be genetically normal given some these disorders could be spontaneous. However depending on your history or your partner, a genetic testing or screening could be considered

Usually done during first trimester of pregnancy

That would depend on family history and possible other circumstances to discuss with your doctor. Always the question is for any test that have outcomes is whether you would have an abortion based on the findings of the test. If that answer is NO, then no testing is important or necessary.

Rob Muller

It really depends on your age, personal and family history. This would be a discussion to have with your provider at your first visit.

Only if you know of any in your or Dad’s family. To test for all known genetic disorders would destroy the kid’s college fund.

Definitely if you're 35 years or older or have a family history of genetic disorders or have abnormal pregnancy screening tests.