Expanded Non-Invasive Prenatal Testing in Thailand: Clinical Insights

Expanded non-invasive prenatal testing (NIPT) implemented in routine prenatal care in Thailand accurately detects common chromosomal abnormalities and materially influences pregnancy outcomes. This large-scale implementation clarifies real-world performance in a middle-income setting and strengthens confidence in population-level prenatal screening strategies.

Compared with prior reports from high-income settings, the Thai data refine expectations for screening accuracy and delineate where expanded panels add value versus where limits remain. The findings show improved detection for common autosomal trisomies while uncertainty persists for rarer anomalies — setting the stage for the primary detection data below.

In a real-world cohort of >19,000 pregnancies, expanded NIPT showed sensitivity of 97.92% for trisomy 21 and 94.12% for trisomy 18, with lower (fair) sensitivity for trisomy 13 and for sex chromosome aneuploidies. Reported positive predictive values were 87.04% for T21, 69.57% for T18, 50% for T13, and 54.55% for SCAs; PPV will vary with condition prevalence and individual pretest probability. These performance metrics support integrating expanded NIPT into routine screening for common aneuploidies.

By contrast, rare autosomal trisomies had low PPV (13.3%) and higher false-positive rates — principal performance challenges demonstrated in the study’s rare-trisomy data. Such results can cause anxiety and prompt additional diagnostic procedures; because PPV depends strongly on prevalence, interpretation of rare positive findings requires caution and planning for confirmatory diagnostic testing.

Key Takeaways:

• What’s new — high sensitivity for common trisomies, especially T21 and T18.
• Who’s affected — most pregnant people gain clearer risk assessment; rare positive results change management and >95% of those with high-risk findings pursued diagnostic testing.
• What changes next — incorporate expanded NIPT into risk-stratification pathways while ensuring counseling about PPV and plans for confirmatory testing.