Correlation Between Middle Cerebral Artery Peak Systolic Velocity and Neonatal Haemoglobin as a Marker of Fetal Anaemia

Introduction: Fetal anaemia is an important cause of perinatal morbidity and mortality. Middle cerebral artery peak systolic velocity (MCA-PSV) measured by Doppler ultrasound has emerged as a reliable non-invasive tool for its assessment. However, its correlation with haemoglobin levels in heterogeneous clinical populations requires further evaluation. This study aimed to evaluate the correlation between MCA-PSV and cord blood haemoglobin and to assess the diagnostic utility of MCA-PSV in predicting anaemia at birth. Materials and methods: This prospective observational study was conducted over six months at a tertiary care centre and included 100 singleton pregnancies. MCA-PSV was measured using standardised Doppler techniques and expressed as multiples of the median (MoM). Cord blood haemoglobin was measured within 24 hours of birth. Correlation between MCA-PSV and haemoglobin was assessed using Pearson’s correlation coefficient. Diagnostic performance of MCA-PSV MoM ≥1.5 was evaluated using sensitivity, specificity, and predictive values. Results: A significant moderate inverse correlation was observed between MCA-PSV and cord blood haemoglobin (r = −0.42, p < 0.001). Anaemia at birth was present in 86 (86%) cases, with moderate-to-severe anaemia in 52 (52%). MCA-PSV and MoM values were significantly higher in anemic neonates (p < 0.001). MCA-PSV MoM increased with the severity of anaemia (p < 0.001). A threshold of ≥1.5 MoM showed excellent specificity (100%) and positive predictive value (100%) but low sensitivity (8.1%). Conclusion: MCA-PSV demonstrates a significant inverse correlation with haemoglobin levels and is a useful non-invasive marker for fetal anaemia. While highly specific, its low sensitivity limits its role as a screening tool, emphasising the need for integrated clinical assessment.