A 32-year-old woman, gravida 2 para 1, at 12 weeks’ gestation is referred for chorionic villus sampling (CVS) due to an increased risk of chromosomal abnormalities noted during her first-trimester ultrasound and screening tests. She has no significant medical history and had a normal pregnancy with her first child. CVS Findings: Karyotype Results: Mosaic trisomy 16 detected in the placental sample. Interpretation: Confined placental mosaicism (CPM) suspected, but fetal involvement cannot be ruled out. What is the primary follow-up test to confirm whether the placental mosaicism detected on chorionic villus sampling (CVS) involves the fetus?
