Birth defect testing should be scheduled

All pregnant women, regardless of their age, should be offered screening for Down syndrome before the 20th week of pregnancy, according to a new Practice Bulletin issued by the American College of Obstetricians and Gynecologists (ACOG). Previously, women were not automatically offered genetic counseling and diagnostic testing for Down syndrome by amniocentesis or chorionic villus sampling (CVS) if they were 35 years and older.

The new ACOG guidelines recommend that all pregnant women consider less invasive screening options for assessing their risk for Down syndrome, a common disorder that is caused by an extra chromosome and can result in congenital heart defects and mental retardation. ACOG also advises that all pregnant women, regardless of their age, should, nevertheless, have the option of more invasive diagnostic testing.

Reasons cited for these new recommendations include recent improvements in screening and challenges to previous age cutoffs. ACOG recommends nuchal translu-cency (NT) measurement and biochemical marker screening for women who present for prenatal care in the first trimester. Those first seen in the second trimester should be offered ultrasound examination and screening for a combination of four biochemical markers.

The bulletin also states:
• A combination of first- and second-trimester screening is more sensitive and results in fewer false-positives than first-trimester screening alone.

• Women found to be at increased risk of having a baby with Down syndrome as the result of first-trimester screening should be offered genetic counseling and the option of chorionic villus sampling (CVS) or mid-trimester amniocentesis.

• Neural tube defect screening should be offered in the mid-trimester to women who elect only first-trimester screening for Down syndrome.
More detailed information is available on the ACOG website at www.acog.org

This information is provided by the Medical Society of the State of New York (MSSNY). For more health-related information and referrals to physicians in your community, log on to MSSNY’s website at www.mssny.org.