Ethnic Variations in Cardiac Adaptation During Pregnancy: Implications for Clinical Practice

A new systematic review found that pregnant Asian women have smaller left ventricular chambers alongside higher left ventricular ejection fraction compared with Western cohorts. This directional difference is reproducible across late-gestation studies and contrasts pooled Western data that report larger cavities with modestly attenuated longitudinal deformation.

These findings challenge the one‑size‑fits‑all reference ranges commonly used in pregnancy echocardiography. Left ventricular global longitudinal strain (GLS) tended to be more favorable in Asian cohorts, and noncardiac factors such as thoracoabdominal geometry—including measures like the modified Haller Index—are plausible contributors to measured differences. Interpreting strain and chamber geometry therefore requires contextualization by population-specific anatomy and loading conditions to avoid overcalling small deviations from a single universal norm.

The review assessed left ventricular chamber size, LVEF, GLS, and indexed values, and found that ethnic differences persisted after body surface area indexing. Body‑size normalization attenuated but did not eliminate group separation. Substantial heterogeneity in study design, imaging platforms, vendor-specific GLS algorithms, gestational-age inclusion windows, and inconsistent indexing methods could influence pooled estimates and warrants cautious interpretation.

Nevertheless, the directional pattern was consistent across diverse methods and cohorts.