Red blood cell magnesium and hypoxic-ischaemic encephalopathy

In developing countries, birth asphyxia is frequently associated with hypoxic ischaemic encephalopathy. This has been attributed to inadequate obstetric care but poor nutrition may also be important. This study determines the association between magnesium stores and hypoxic ischaemic encephalopathy. The level of red blood cell magnesium was measured on 572 women in labour and on selected offspring in a teaching hospital in South Africa. Fifty five of the 572 women delivered infants with hypoxic ischaemic encephalopathy and had significantly lower red blood cell magnesium levels (1.40 mmol/l) than controls. In the latter the levels varied somewhat with the mode of delivery, vertex births 1.76 mmol/l, Caesarean sections 1.67 mmol/l and vacuum extractions 1.61 mmol/l. Infants with hypoxic ischaemic encephalopathy had a significantly lower red blood cell magnesium level (1.39 mmol/l) than normal infants (1.61 mmol/l). Fifty four of 55 babies were black and from poor social circumstances and nutritional deficiency may be relevant. Maternal height, age and the duration of labour did not influence the chance of hypoxic ischaemic encephalopathy and affected infants were more likely than normal ones to be meconium stained (50%), to have a low Apgar score (58%) and to need endotracheal intubation at birth (54%). An intervention study in early pregnancy may determine magnesium's role in hypoxic ischaemic encephalopathy associated with asphyxia.