Mobile Site ›

Test Catalog

Test ID: MCC    
Maternal Cell Contamination, Molecular Analysis

Useful For Suggests clinical disorders or settings where the test may be helpful

Ruling out the presence of maternal cell contamination within a fetal specimen


This test is required for all prenatal testing performed in Mayo's molecular and biochemical genetics laboratories

Genetics Test Information Provides information that may help with selection of the correct test or proper submission of the test request

Required in conjunction with molecular and biochemical prenatal testing only.

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

One of the risks associated with prenatal testing is maternal cell contamination (MCC), which can occur when a fetal specimen comes into contact with maternal blood or tissue. The risk of MCC is associated with procedures such as chorionic villus sampling, amniocentesis, or extraction of fetal blood from the umbilical cord (cord blood). If MCC is present, the maternal DNA may mask the results of any genetic testing performed on the fetal DNA. Therefore, the results of prenatal testing may be compromised.


To rule out the presence of MCC, a maternal blood specimen is necessary for comparison of maternal and fetal chromosomal markers. The presence of both maternal and non-maternal alleles for each fetal marker indicates the fetal specimen is not contaminated. MCC is confirmed when both alleles in the fetus are maternal.

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

An interpretative report will be provided.

Interpretation Provides information to assist in interpretation of the test results

An interpretive report will be provided.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

A previous bone marrow transplant from an allogenic donor will interfere with testing. Call Mayo Medical Laboratories for instructions for testing patients who have received a bone marrow transplant.


This test does not rule out the presence of low-level maternal cell contamination (<10%).

Special Instructions and Forms Describes specimen collection and preparation information, test algorithms, and other information pertinent to test. Also includes pertinent information and consent forms to be used when requesting a particular test