confined placental mosaicism
Also written as: CPM — confined placental mosaicism
A condition where chromosomal abnormalities are present in placental tissue but not in the fetus itself.
Full Definition
Confined placental mosaicism (CPM) occurs when chromosomal abnormalities are found in the placenta but the fetus has normal chromosomes. This phenomenon can lead to discrepant results between chorionic villus sampling and the actual fetal karyotype, as CVS samples placental rather than fetal tissue. CPM affects approximately 1-2% of pregnancies and can result in false-positive results for certain genetic conditions. It may also be associated with intrauterine growth restriction and other pregnancy complications.
Usage
Usage note: Commonly abbreviated as CPM in clinical practice.
In Context
- "Confined placental mosaicism was suspected when CVS showed trisomy 16 but amniocentesis revealed normal chromosomes." — Case study report
- "The laboratory reported possible confined placental mosaicism, recommending follow-up amniocentesis for confirmation." — Prenatal testing result