Gene markers for cardiomyocyte growth, proliferation and remodeling were examined in mouse fetuses and adult male offspring exposed to maternal low-protein (LP) diet during pregnancy. Whole heart volume, measured by magnetic resonance imaging, was smaller in day 15 LP fetuses v. those from chow-fed dams (C), whereas heart volume was greater in adult LP v. C offspring. These LP offspring were hypertensive and had larger cardiomyocytes v. C animals. The mRNA levels of cyclin G1, a marker for cell growth, were lower in LP fetal hearts v. C hearts, but similar in the left ventricle of adult LP and C offspring. Opposite trends were found in brain natriuretic peptide levels (a marker of cardiac hypertrophy). Thus, maternal LP during pregnancy results in smaller fetal hearts and is accompanied by changes in expression of genes involved in cardiomyocyte growth, which are associated with cardiac hypertrophy and hypertension in adulthood.