First-Trimester PRISCA Screening for Trisomy 21 Risk in a Kyrgyz Cohort: Biochemical Marker Profiles and Implementation Insights

The most prevalent viable chromosomal anomaly is trisomy 21, which causes the highest newborn morbidity and mortality worldwide. High-risk pregnancies must be identified early by prenatal screening, especially in low-resource countries where invasive diagnostic treatments are scarce. This cross-sectional study examined first-trimester PRISCA (Prenatal Risk Calculation Software) screening in 50 Kyrgyz pregnant women between 11 and 14 weeks. Mothers' serum levels of PAPP-A and free β-hCG were measured and converted to multiples of the median (MoM). The PRISCA method estimated trisomy 21 risk from ultrasound and maternal data. Low-risk findings were found in 72% of participants and high-risk in 26%. PAPP-A MoM values were substantially lower and free β-hCG MoM values were higher in high-risk pregnancies compared to low-risk ones. PAPP-A MoM values were negatively correlated with trisomy 21 risk (r = -0.38, p = 0.007), but free β-hCG MoM values were positively correlated (r = 0.51, p < 0.001). Both maternal hematologic and urinalysis parameters were within reference limits and did not enhance trisomy 21 risk. These findings show that PRISCA-based screening for trisomy 21 risk assessment in Kyrgyzstan may improve prenatal care in resource-limited settings. Due to budget constraints, this study provides preliminary PRISCA application insights but no diagnostic confirmation or outcome data.