Diagnostic and Interpretive Gains in First Trimester Congenital Heart Disease via Foundation Models

1School of Computer Science, Wuhan University, Wuhan, China
2College of Computing and Data Science, Nanyang Technological University, Singapore
3Department of Ultrasound, Beijing Obstetrics and Gynecology Hospital, Capital Medical University; Beijing Maternal and Child Health Care Hospital, Beijing, China
Manuscript, 2026

Abstract

Effective first-trimester screening for congenital heart disease (CHD) remains an unmet clinical need, and automated analysis is critical for clinical decision-making. Despite recent advances of foundation models in clinical workflows, the ability to analyze CHD remains limited, primarily due to the lack of CHD-oriented reasoning annotation. This paper aims to bridge this gap. Specifically, we collect a large cohort of first-trimester cardiac screenings across multiple regions in China, comprising 10,821 image-pathology pairs with clinical imaging phenotypes. Based on this cohort, we develop CHD-FM, a versatile foundation model tailored for first-trimester CHD analysis. Through a multi-stage training paradigm, including visual domain adaptation and clinical phenotypes reinforcement, CHD-FM systematically acquires disease diagnosis knowledge and reasoning interpretive capabilities for the CHD scope. In rigorous evaluations, CHD-FM consistently outperformed state-of-the-art commercial and open-source foundation models, and matched or surpassed experienced clinicians across retrospective, prospective, and external cohorts.

Method Overview

Overview of CHD-FM

Overview of CHD-FM for first-trimester congenital heart disease analysis.

Performance Comparison

Performance comparison with commercial and open-source models

Performance comparison with closed commercial models and open-source foundation models across retrospective and out-of-domain cohorts.

Interpretability Assessment

Diagnostic thinking process, confusion matrix, and clinical physician assessment

Diagnostic reasoning examples, confusion matrices, and clinical physician assessment of CHD-FM and comparison models.

Code Release

The public repository is code-only and does not include fetal ultrasound images, patient tables, annotations, trained checkpoints, generated predictions, commercial API outputs, logs, or doctor-scoring results.