MaryBeth is 16 weeks pregnant and undergoes MSAFP screening. Her MSAFP level is 3.0 multiples of the median above normal. Ultrasound confirms the gestational age and the presence of only a single fetus. What additional testing should be offered to MaryBeth?
a. At this point in MaryBeth’s pregnancy, she should undergo cordocentesis, a method to obtain lymphocytes from the infant , to obtain DNA for use in direct mutation analysis of the suspect genes.
b. Chorionic villus sampling should be performed on MaryBeth to obtain DNA for fetal karyotyping studies.
c. MaryBeth’s age should be factored into any risk calculation.
d. A neural tube defect should be suspected, and high-resolution ultrasound should be the next step.