Potential prenatal predictions of Down syndrome: a statistical analysis

Area of Science:

• Prenatal screening
• Maternal serum markers
• Fetal biometry

Background:

• Down syndrome is a leading cause of intellectual disability.
• Accurate prenatal screening is crucial for timely intervention and genetic counseling.
• Current screening methods can be improved by combining multiple markers.

Purpose of the Study:

• To assess the feasibility of combining multiple screening tests for Down syndrome detection.
• To evaluate the relationship between maternal serum human chorionic gonadotropin (hCG), alpha-fetoprotein (AFP), and fetal biometry (biparietal diameter/femur length).
• To determine if these markers can be used independently or in combination for Down syndrome risk assessment.

Main Methods:

• Serum samples from women with known maternal age and weight were analyzed for hCG and AFP concentrations.
• Fetal biparietal diameter and femur length were measured.
• Statistical analysis was performed to evaluate the independence and correlation between the markers, correcting for gestational age and maternal weight.

Main Results:

• Maternal serum hCG, AFP, and fetal biometry were found to be largely independent predictors of Down syndrome risk.
• A slight positive correlation (r = 0.10) was observed between maternal serum AFP and hCG.
• All three markers exhibited a log-normal distribution, suitable for combined analysis.

Conclusions:

• Combining maternal serum hCG, AFP, and fetal biometry is a scientifically sound approach for prenatal Down syndrome screening.
• These markers can be used individually or in combination to identify pregnancies at increased risk.
• This multi-marker approach enhances the accuracy and feasibility of prenatal Down syndrome detection.