[Follow-up of pregnancies with red-cell allo-immunisation: State-of-the art]

Area of Science:

• Obstetrics and Gynecology
• Fetal Medicine
• Immunology

Background:

• Anti-RhD alloimmunization, while reduced by prophylaxis, remains a primary cause of fetal anemia.
• Severe fetal complications include hydrops, anoxic brain lesions, and fetal demise.
• Neonatal complications like severe jaundice and anemia requiring transfusion persist, alongside risks of bilirubin encephalopathy.

Purpose of the Study:

• To outline the diagnostic and management strategies for pregnancies complicated by maternal alloimmunization.
• To highlight the importance of antibody identification, dosage, and titration in monitoring.
• To discuss the role of non-invasive fetal RHD genotyping and Doppler assessments in managing fetal anemia risks.

Main Methods:

• Identification and titration of maternal antibodies (anti-RhD, anti-Kell, anti-c).
• Non-invasive fetal RHD genotyping from maternal blood for RhD alloimmunization.
• Weekly Doppler assessment of middle cerebral artery peak systolic velocity (MCA-PSV) for fetal anemia detection.
• Intrauterine fetal transfusion (IUT) as the primary treatment for fetal anemia.

Main Results:

• Non-invasive RHD genotyping can confirm feto-maternal incompatibility.
• MCA-PSV Doppler effectively identifies fetal anemia before hydrops develops.
• Intrauterine transfusion carries a 3% risk per procedure, with cumulative risks exceeding 10% in severe cases.

Conclusions:

• Despite prophylaxis, maternal alloimmunization necessitates vigilant monitoring and timely intervention.
• Non-invasive methods and Doppler assessments improve early detection of fetal anemia.
• Intrauterine transfusion is effective but associated with significant procedural risks, emphasizing the need for careful management.