Maternal serum alpha-fetoprotein prenatal screening for Down syndrome

Area of Science:

• Prenatal diagnostics
• Maternal-fetal medicine
• Biochemical screening

Background:

• Maternal serum alpha-fetoprotein (MSAFP) is a key biomarker in prenatal screening for Down syndrome.
• Accurate interpretation of MSAFP levels is crucial for identifying pregnancies at increased risk.
• Factors such as maternal weight and race can influence MSAFP levels, potentially affecting screening accuracy.

Purpose of the Study:

• To investigate the relationship between maternal serum alpha-fetoprotein (MSAFP) levels, maternal age, and Down syndrome risk factors.
• To assess the impact of adjustments for maternal weight and race on MSAFP screening results.
• To evaluate the utility of race and area-specific medians in prenatal MSAFP screening for Down syndrome.

Main Methods:

• Retrospective analysis of MSAFP levels in a defined population.
• Statistical adjustments for maternal weight and race.
• Comparison of Down syndrome risk factor prevalence before and after adjustments.
• Utilized race and area-specific medians for MSAFP interpretation.

Main Results:

• After adjusting for race and maternal weight, 3.84% of women exhibited Down syndrome risk factors comparable to a 35-year-old woman with a normal pregnancy.
• Maternal weight adjustment significantly reduced the proportion of low MSAFP values from 5.12% to 3.40%.
• The use of race and area-specific medians proved important for accurate prenatal MSAFP screening.

Conclusions:

• Maternal weight and race are significant confounders in MSAFP screening for Down syndrome.
• Adjusting MSAFP levels for maternal weight and race improves the precision of Down syndrome risk assessment.
• Race and area-specific medians enhance the effectiveness of prenatal MSAFP screening programs.