AMP case report: A vanishing twin as an explanation for discordant fetal sex results with NIPS and ultrasound

1. Noninvasive prenatal screening is performed using cell-free DNA isolated from which of the following sample types?
a. Amniotic fluid
b. Cultured chorionic villi
c. Maternal plasma
d. Maternal saliva

2. Which of the following statements about NIPS is true?
a. NIPS can be performed using Sanger se­quencing.
b. NIPS and maternal serum screening have comparable sensitivity and specificity.
c. NIPS results can be affected by maternal conditions.
d. Sex chromosome aneuploidies cannot be identified.

3. Which of the following statements about vanishing twin pregnancies is true?
a. A VT pregnancy has no clinical significance.
b. NIPS results are never affected by a VT.
c. A fetal demise has occurred.
d. cfDNA from a demised twin is rapidly cleared from the maternal circulation.

1. Noninvasive prenatal screening is performed using cell-free DNA isolated from which of the following sample types?
a. Amniotic fluid
b. Cultured chorionic villi
c. Maternal plasma
d. Maternal saliva

2. Which of the following statements about NIPS is true?
a. NIPS can be performed using Sanger se­quencing.
b. NIPS and maternal serum screening have comparable sensitivity and specificity.
c. NIPS results can be affected by maternal conditions.
d. Sex chromosome aneuploidies cannot be identified.

3. Which of the following statements about vanishing twin pregnancies is true?
a. A VT pregnancy has no clinical significance.
b. NIPS results are never affected by a VT.
c. A fetal demise has occurred.
d. cfDNA from a demised twin is rapidly cleared from the maternal circulation.