Can genetic testing prevent birth defects in pregnancy?

No: First genetics are responsible for only some birth defects. Second the genetic tests that are usually done in pregnancy are for chromosomal problems (like down's syndrome), not for single gene problems or genetic syndromes.

Help to make choice: Karyotype or chromosome copy number analyses of fetal cells can reveal chromosome abnormalities of a fetus. In addition, several other genetic tests can detect specific genetic defects of a fetus. If the test is performed sufficiently early, one can make a decision what to do with the pregnancy.

Nope.: Genetic prenatal testing can detect many chromosomal or microscopic dna defects - but it cannot prevent birth defects! 2-4% of all newborns will have a minor or major birth defect and the vast majority of those have unknown genetic underpinnings at this time, although many of us are working to change that. Take Folic Acid 1-5 mg daily to prevent 75-95% of major neural/cardiac fetal anomalies!