Anti-Inb alloimmunisation in pregnancy: Anaesthetic and perioperative blood management for caesarean delivery - A case report

ABSTRACT

Anti-In ^b , a rare high-frequency antigen antibody of the Indian blood group system, renders compatible banked blood virtually unavailable. A 34-week gravida 3 para 2 patient with dual alloimmunisation, anti-In ^b (titre 1:128) and anti-D (titre 1:64), underwent elective caesarean delivery. Antenatal iron supplementation raised haemoglobin from 9.6 g/dL to 11.2 g/dL, enabling a preoperative autologous blood donation of 325 mL. The serial middle cerebral artery peak systolic velocity Doppler remained below 1.5 multiples of the median throughout, excluding foetal anaemia. The patient’s brother was identified as the sole compatible allogeneic donor. Subarachnoid block with hyperbaric bupivacaine 9 mg achieved T5 blockade. The estimated blood loss was 900 mL due to uterine atony; stepwise uterotonic therapy was employed, and only the autologous unit was transfused. Maternal recovery was uneventful; the neonate required phototherapy but was discharged well. Antenatal haemoglobin optimisation and preoperative autologous donation are essential strategies when compatible blood is unavailable.