Cardiac function in early onset small for gestational age and growth restricted fetuses

To examine cardiac function in appropriately grown, small for gestational age and intrauterine growth restricted fetuses and investigate the relationship between cardiac function and fetal arterial and venous Doppler parameters.

Myocardial performance index, isovolumetric contraction time, isovolumetric relaxation time, ejection time, and umbilical artery, middle cerebral artery and ductus venosus Doppler pulsatility index were measured for women between 24 and 32 weeks with small for gestational age and intrauterine growth restricted fetuses. Forty-eight appropriately grown, 11 small for gestational age and 12 intrauterine growth restricted cases were included. The relationship between cardiovascular parameters and gestation was defined and Doppler values converted to Z-scores in relation to gestational age.

In small for gestational age fetuses and fetuses with intrauterine growth restriction the myocardial performance index was 0.66 (0.63-0.7) and 0.64 (0.60-0.67), respectively, and compared to appropriately grown fetuses, at 0.45 (0.43-0.47), was significantly increased (p=0.001). No relationship was found between the myocardial performance index and arterial and venous Doppler Z-score.

Small for gestational age and intrauterine growth restricted fetuses demonstrate altered cardiac function in the late second and early third trimester of pregnancy. Importantly, the myocardial performance index is raised in small for gestational age fetuses before the arterial and venous Doppler abnormalities that characterize hypoxia are evident.