maternal cell contamination
Presence of maternal cells in fetal samples that can lead to false-negative results in prenatal genetic testing.
Full Definition
Maternal cell contamination occurs when maternal cells are inadvertently included in fetal tissue samples during prenatal procedures such as amniocentesis or chorionic villus sampling. This contamination can result in false-negative results for fetal genetic conditions, particularly when testing for recessive disorders or when the fetus is affected but the contaminating maternal cells are normal. Laboratory protocols typically include measures to detect and quantify maternal contamination, and genetic counselors must consider this possibility when interpreting results. The risk is higher with certain sampling techniques and can affect the accuracy of both chromosomal and single-gene disorder testing.
Usage
Usage note: Often abbreviated as 'MCC' in laboratory reports.
In Context
- "The laboratory detected 15% maternal cell contamination in the CVS sample, requiring repeat testing." — Genetic testing report
- "Maternal cell contamination must be considered as a potential cause of discordant results between ultrasound findings and genetic testing." — Clinical guideline