Reference Ranges for the Fetal Myocardial Performance Index Assessed by Conventional Doppler Between 11 + 0 and 14 + 0 Weeks of Gestation.
TL;DR
The Tei index can be measured between 11 and 14 weeks of gestation using noninvasive ultrasound techniques and contributes to the limited literature on first-trimester fetal cardiac functional assessment.
Abstract
Background
Early fetal cardiac evaluation during the first trimester has become increasingly feasible due to advancements in ultrasound technology. The myocardial performance index (Tei index) is a Doppler-derived parameter that assesses combined systolic and diastolic cardiac function.
Objective
To assess fetal cardiocirculatory status using two-dimensional and Doppler ultrasound during routine first-trimester evaluation and to establish reference ranges for the Tei index between 11 + 0 and 14 + 0 weeks of gestation. STUDY
Design
This cross-sectional study included 470 healthy singleton fetuses evaluated with two-dimensional and Doppler ultrasound. The Tei index was measured for both ventricles following a standardized protocol.
Results
The mean Tei index was 0.47 (±0.08) for the right ventricle and 0.46 (±0.08) for the left, with a statistically significant difference (p = 0.032) that was not clinically relevant. The index followed a log-normal distribution. No significant correlation was observed with crown-rump length, while a weak but statistically significant correlation was observed between the Tei index and left-ventricular heart rate.
Conclusion
The Tei index can be measured between 11 and 14 weeks of gestation using noninvasive ultrasound techniques. This study provides reference data for both ventricles in a Latin American cohort and contributes to the limited literature on first-trimester fetal cardiac functional assessment. Further prospective studies are needed before routine clinical implementation can be recommended.