Jean Fitzgerald, MD, of the Doylestown Women’s Health Center, is the director of the OB/GYN Department at Doylestown Hospital

Q: What do I need to know about prenatal screenings and advanced genetic testing?
Dr. Fitzgerald: There is an important distinction between routine prenatal screenings and advanced diagnostic tests. Screenings are noninvasive so just about everyone has them. We advise all mothers to consider having routine blood tests to assess the baby’s risk for certain birth defects such as Down syndrome and spina bifida. An ultrasound at 18 to 20 weeks is also recommended to check the baby’s growth and development.

There is a new noninvasive option available that combines ultrasound with a two-part blood test screening. Called nuchal translucency screening, it offers higher detection rates for chromosomal abnormalities than traditional quad marker screening.

Q: When should I consider advanced genetic testing?
Dr. Fitzgerald: Diagnostic genetic tests, such as amniocentesis and chorionic villus samples (CVS) are routinely offered when the mother is over 35, has a family health history or a positive prenatal screen. Most doctors, however, now discuss genetic testing with all expectant women.

Q: Are genetic tests risky?
Dr. Fitzgerald: There is a slight risk associated with advanced genetic testing, such as amniocentesis and CVS. These tests are done only when initial screenings indicate need and the patient agree