Changes in myocardial performance index and aortic isthmus and ductus venosus Doppler in term, small-for-gestational age fetuses with normal umbilical artery pulsatility index.

OBJECTIVE

To evaluate the changes in myocardial performance index (MPI) and aortic isthmus (AoI) and ductus venosus (DV) Doppler in term, small-for-gestational age (SGA) fetuses with normal umbilical artery (UA) Doppler.

METHODS

MPI, AoI and DV pulsatility indices (PI) were measured within 1 week prior to delivery in a cohort of 178 term singleton consecutive SGA fetuses with normal UA-PI (< 95(th) percentile) and 178 controls matched by gestational age. Cardiovascular parameters were converted into Z-scores and values above the 95(th) centile defined as abnormal.

RESULTS

Median gestational age at inclusion and at delivery was 35.7 and 38.6 weeks, respectively. Compared to controls, SGA fetuses showed significantly higher values in MPI and AoI-PI and similar values in DV-PI. SGA fetuses showed a significantly higher proportion of increased MPI (28.1 vs. 6.7%; P < 0.01) and abnormal AoI-PI (14.6 vs. 5.1%; P < 0.01) than controls. The proportion of cases with abnormal DV-PI was similar between SGA cases and controls. Retrograde net blood flow in the AoI was observed in 7.3% of the SGA cases and in none of the controls.

CONCLUSION

A proportion of SGA fetuses show cardiovascular Doppler abnormalities. This information might be of clinical relevance in improving the detection and management of late-onset intrauterine growth restriction.