A 40-year-old primigravid client with AB-positive blood visits the outpatient clinic for an amniocentesis at 16 weeks' gestation. The nurse determines that the most likely reason for the client's...

A 40-year-old primigravid client with AB-positive blood visits the outpatient clinic for an amniocentesis at 16 weeks' gestation. The nurse determines that the most likely reason for the client's amniocentesis is to determine if the fetus has which of the following?

1. Cri-du-chat syndrome.

2. ABO incompatibility.

3. Erythroblastosis fetalis.

4. Down syndrome.