What is the chance of aneuploidy associated with cystic hygroma?

Cystic hygroma is a fluid-filled sac that results from a blockage in the lymphatic system and is most commonly found in the neck region of a fetus. It is often associated with several chromosomal abnormalities, particularly aneuploidies such as Turner syndrome (45,X).

The connection between cystic hygroma and aneuploidy is significant; studies suggest that the presence of a cystic hygroma increases the risk of associated genetic abnormalities. When cystic hygroma is detected in a fetus, approximately 50% of cases are associated with a chromosomal abnormality. This figure encompasses a range of conditions, including both aneuploidies and other genetic syndromes.

Understanding this statistic is crucial for clinicians when managing pregnancies with detected cystic hygromas, as it necessitates further genetic counseling and possible diagnostic testing, such as chorionic villus sampling or amniocentesis, to assess for aneuploidy and other chromosomal anomalies. Thus, recognizing that the presence of cystic hygroma correlates with around a 50% risk of aneuploidy helps inform clinical decision-making and the counseling of expectant parents.