A study of different scenarios of fetal middle cerebral artery peak systolic velocity in an Indian population

Fetal Middle Cerebral Artery Peak Systolic Velocity (MCA-PSV) is being increasingly used for non-invasively diagnosing fetal anemias irrespective of their cause. A study was therefore undertaken to find out what different scenarios can be encountered in the local obstetric population. Doppler ultrasound measurements of fetal MCA-PSV were done in 1200 pregnant women who were referred for antenatal ultrasound between 12 - 40 weeks of gestation. Statistical analysis was done using Microsoft Excel 2007 and SPSS software version 12. The different scenarios encountered in this study were then compiled and are presented here. With increasing gestational age, the value of MCA-PSV was seen to increase correspondingly in all normal fetuses. This correlation between the two was thus positive and was found to be statistically significant (p < 0.05). Abnormally raised values of MCA-PSV were seen in fetuses with severe anemia due to ABO-Rh Isoimmunization which left untreated, ultimately resulted in fetal hydrops. Almost similar and normal values were seen in separate as well as conjoint healthy twins. Abnormally elevated values were seen in twins with discordant growths. Fetal MCA-PSV is very useful to confirm the presence or absence of fetal anemia irrespective of underlying cause in singleton as well as twin pregnancies. For complete assessment, it is essential that the specialist is thoroughly aware of the different scenarios that can be encountered while using this non-invasive method.