Second-trimester cancer antigen 125 and Down's syndrome

Area of Science:

• Obstetrics and Gynecology
• Prenatal Diagnostics
• Biochemistry

Background:

• Down syndrome is a genetic disorder.
• Early detection of Down syndrome is crucial for prenatal care.
• Cancer antigen 125 (CA 125) is a biomarker investigated for various conditions.

Purpose of the Study:

• To investigate the potential of maternal serum and amniotic fluid CA 125 levels for detecting Down syndrome during the second trimester of pregnancy.

Main Methods:

• Retrospective analysis of stored maternal serum samples from Down syndrome pregnancies and controls.
• Analysis of second-trimester amniotic fluid samples from Down syndrome and unaffected pregnancies for CA 125 levels.

Main Results:

• Maternal serum CA 125 levels were lower in Down syndrome pregnancies (median 0.72 multiples of unaffected median).
• No significant difference in median CA 125 levels between affected and unaffected pregnancies.
• Considerable overlap in CA 125 values between cases and controls.
• Amniotic fluid CA 125 levels showed similar distributions in affected and unaffected pregnancies.

Conclusions:

• Second-trimester maternal serum or amniotic fluid CA 125 levels do not appear to be associated with Down syndrome.
• CA 125 assay is not a reliable marker for detecting Down syndrome in the second trimester based on this study.