Study on Factors Influencing Fetal Y Chromosome Concentration Based on Beta Regression and Rank Correlation Analysis

Abstract

This study conducted an association analysis and regression modeling of factors influencing fetal Y chromosome concentration in male fetuses, aiming to quantify the complex relationship between fetal Y chromosome concentration (proportional data) and physiological indicators such as maternal gestational age and BMI. First, the attached data underwent Shapiro-Wilk tests, confirming that all variables—including fetal Y chromosome concentration—failed to meet the assumption of Gaussian distribution. Consequently, the nonparametric Spearman rank correlation coefficient was selected for association analysis. The correlation heatmap revealed a positive correlation between Y chromosome concentration and gestational age (correlation coefficient: 0.188) and a negative correlation with maternal BMI (correlation coefficient: -0.155). Considering that Y chromosome concentration is a ratio-type variable within an interval, a beta regression model was established, incorporating nonlinear terms and mixed effects to enhance model accuracy. Comparing the beta regression model with various nonlinear regression models, the beta regression model demonstrated superior parameter significance and an MAE value of 0.026146, confirming strong correlation among model indicators. In terms of research significance, the established Beta regression model outperforms traditional nonlinear models in both parameter significance and predictive accuracy (MAE: 0.026146). This model systematically reveals the influence of various factors on Y chromosome concentration, holding significant value for clinically precise determination of optimal NIPT testing timing and personalized risk assessment.