Once you’re pregnant, your doctor will suggest a variety of genetic screening tests for birth defects. These screen for chromosomal disorders and neural tube defects. Generally, you’ll be told what each test can detect, how accurate it is and what’s next if the results are abnormal. Be aware that some screening tests have a fairly high rate of false positive results (meaning they show chances of birth defects when babies are actually OK).
Whether or not to pursue this testing is up to you, but all women are offered some type of screening test, regardless of their age or risk factors. Screening tests only screen for the chance of a genetic condition; if there’s a concerning result, you’re offered a diagnostic test, which involves tissue or fluid sampling, to confirm it.