Normal fetal echocardiography ratios - a multicenter cross-sectional retrospective study

Area of Science:

• Cardiology
• Fetal Medicine
• Medical Imaging

Background:

• Normal fetal echocardiography ratios are crucial for assessing blood flow balance and predicting congenital heart disease.
• Standardized studies with large sample sizes are currently lacking for these important metrics.

Purpose of the Study:

• To establish comprehensive reference ranges for 11 fetal cardiac structural and hemodynamic ratios.
• To determine how these ratios evolve with gestational age using multicenter data.

Main Methods:

• A multicenter, cross-sectional retrospective study involving 23,313 normal fetal echocardiograms.
• Analysis of 11 key fetal cardiac ratios, including heart diameter and valve E/A velocity ratios.
• Nonparametric quantile regression was used to establish reference ranges across gestational ages.

Main Results:

• Normal percentile reference ranges for 11 ratios were established for each gestational day.
• The right heart system shows consistent dominance, with its diameter ratio accelerating after 21.7 weeks.
• Mitral and tricuspid valve E/A ratios increase with gestational age, peaking in growth rate around 25.7 weeks.

Conclusions:

• The study provides updated references for routine obstetric screening.
• These findings enhance the understanding of normal fetal heart growth and developmental patterns.