Fetal MCA Doppler study

This trial is currently recruiting. The trial is open for other centres to join the study.

Red cell alloimmunisation is estimated to affect 0.1 to 0.6% of all live births. Treatment of the resultant fetal anaemia with intrauterine fetal blood transfusion has been associated with survival rates in excess of 90%. However, intrauterine fetal blood sampling and transfusion is an invasive procedure, with recognised complications, which may result in the need for early birth, and rarely mortality. More recently, reports have emerged utilising Doppler ultrasound to measure the fetal middle cerebral artery (MCA) peak systolic velocity (PSV) to determine the presence of fetal anaemia. Systematic review of the literature has indicated a lack of information from randomised controlled trials comparing this technique with standard studies reporting the use if fetal MCA PSV in this setting yield conflicting results. Our aim is to assess whether fetal middle cerebral artery (MCA) peak systolic velocity (PSV) can be safely used to determine the timing of second and subsequent fetal blood transfusions, without increasing the risk of adverse fetal and neonatal health outcomes.