An early blood group and antibody screen for maternal red cell antibodies is a standard component of pregnancy management. In proven alloimmunisation, a thorough obstetric and medical history is important. Women with fetuses at high risk of developing fetal anaemia require referral to a maternal–fetal medicine specialist for close antenatal ultrasound surveillance.
- About 1% of pregnant women carry a red cell antibody that has the potential to destroy fetal red blood cells and cause fetal anaemia (alloimmunisation).
- The three most clinically important antibodies in alloimmunisation are Rhesus D, Rhesus c and Kell antibodies.
- Alloimmunised pregnant women whose antibody levels exceed a certain critical threshold are at high risk of their baby developing fetal anaemia and warrant prompt referral to a maternal–fetal medicine specialist.
- Regular in utero ultrasound assessment of the fetal middle cerebral artery is a very sensitive method of detecting anaemia in the fetus of women with high-risk red cell antibodies.
- A fetus that becomes anaemic before 34 weeks’ gestation may require a life-saving in utero fetal transfusion.
- After birth, babies are at increased risk of anaemia and jaundice, which are the neonatal effects of haemolysis.
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