Fetal middle cerebral artery peak systolic velocities in a local Indian scenario

Measurement of fetal middle cerebral artery peak systolic velocity (MCA-PSV) is now universally recommended for noninvasive assessment and follow-up of fetal anemia. However, a literature review suggests that the fetal MCA-PSV range is different for Asian and non-Asian populations. A study was therefore undertaken to compare and contrast MCA-PSV values in the local obstetrical population with those of previously published studies done elsewhere.

Fetal MCA-PSV was measured in normal 100 pregnant women attending the outpatient antenatal clinic using Doppler ultrasonography, which was performed at least once between 12 and 40 weeks of gestation.

A positive statistically significant (P < 0.05) correlation was seen between gestational age and MCA-PSV. The 5th (17.0 vs. 24.9 cm/s), 50th (23.0 vs. 32.4 cm/s), and 95th (38.0 vs. 41.1 cm/s) percentile values of MCA-PSV at 25 weeks of gestation in the present study were consistently lower than those cited in other studies.

The results indicate that a local fetus would be anemic even before its MCA-PSV rises to the internationally accepted standard of fetal anemia. Hence, by the time the MCA-PSV value of the local fetus rises to the point where it is deemed severely anemic as per values mentioned in other published literature, it might be too late for intervention and the fetal health as well as life might be at stake. Each geographic locality should therefore develop its own standard values.