Middle cerebral artery Doppler

Introduction In the last 50 years we have seen tremendous advances in the management of fetal haemolytic anaemia. What was once a disease of high perinatal mortality and morbidity has become a condition readily amenable to antenatal diagnosis and intrauterine fetal therapy. Prior to the 1960s, the management of severe fetal anaemia relied on preterm delivery and subsequent therapy in the neonatal period. In 1961, Liley described the use of amniocentesis to predict the severity of fetal haemolytic anaemia. Amniotic fluid bilirubin concentrations, reflecting the degree of fetal haemolysis, gave indirect assessment of fetal anaemia. The first therapeutic intervention for fetal anaemia was again described by Liley in 1963. He performed the first intrauterine transfusion via the intraperitoneal route. The introduction of real-time ultrasound facilitated needleguided intraperitoneal transfusion in 1977. The first intravascular transfusion, performed fetoscopically, was carried out by Rodeck in 1981. Developments in imaging technology mean that intravascular transfusion is now routinely performed with the aid of ultrasound guidance, and success rates of 92–94% can be expected for the non-hydropic anaemic fetus. In the last twenty years we have witnessed another milestone in the management of fetal haemolytic disease. Prediction of fetal anaemia by the non-invasive method of middle cerebral artery Doppler has revolutionised the assessment of rhesus sensitised pregnancies, and provides the focus of discussion for this article.