The condition persists for about 48 hours and then subsides. A rapid fall in sodium is more likely to cause convulsions. Primary maternal hyperparathyroidism is rare, and usually due to adenoma. There may be hyperemesis, and spontaneous miscarriage. It may be due to fetal parathyroid gland suppression, however some infants have normal or even supranormal levels of parathormone, and the explanation for this is unclear.
Subdural haematoma is fortunately rare, but is usually associated with birth trauma.
It results from tears in the tentorium cerebelli or less commonly the falx cerebri. Towards the end of the first week the head circumference increases rapidly, with clinical deterioration. Ultrasound scans are not good at detecting subdural bleeds, and the investigation of choice is now contrast enhanced MR scanning. Wilson's disease is an inborn error of metabolism which results in accretion of copper due to defective biliary excretion. Haemolysis, renal tubular dysfunction, Kaiser-Fleischer rings and subsequently cirrhosis occur.