Step II apgo question

[dixieflatline]

I'm confused about an answer to a question on APGO. Why is the answer amniocentesis and not cell free DNA testing? Please advise, thanks.

Question:
A 32-year-old G1 woman with an IVF conceived pregnancy at 12 weeks gestation has a slightly increased fetal nuchal translucency (3.0 mm), but her first trimester screen shows no increased risk for Down syndrome or Trisomy 18. Still concerned about the increased nuchal translucency, the patient requests additional testing to exclude chromosomal abnormalities. Which of the following is the next best step to rule out a chromosomal abnormality in this patient?

 

[22031 Alum]

Remember, cell free fetal DNA testing is still a SCREENING test. If the patient already has a negative screen but wants more definitive confirmation, then you'd have to perform a DIAGNOSTIC test. You wouldn't just screen her again l. The options for diagnostic testing are CVS and amnio. 12 weeks is late for CVS, so while it's also early for amnio, you could offer it later, around 16 weeks.

I think the distinction between genetic screening and genetic diagnosis is the point of that question.

 

[dixieflatline]

thank you!