Although its frequency in nations with excellent obstetric services has fallen below 1/500 pregnancies, it is still common in many other countries. The primary pathology is in the placenta, which secretes an anti-angiogenic factor in response to ischaemia, leading to endothelial dysfunction. In fatal cases, there are arterial lesions in many organs including the brain. This is the second most frequent organic psychosis, and the second to be described. Psychoses occur in about 5% of cases, and about 240 detailed cases have been reported. It particularly affects first time mothers. Seizures may begin before, during or after labour, but the onset of psychosis is almost always postpartum. These mothers usually experience delirium but some have manic features. The duration is remarkably short, with a median duration of 8 days. This, together with the absence of a family history and of recurrences, contrasts with puerperal bipolar/cycloid psychoses. After recovery, amnesia and sometimes retrograde memory loss may occur, as well as other permanent cerebral lesions such as dysphasia, hemiplegia or blindness. A variant was described by Donkin . He had been trained by Simpson (one of those who first recognized the importance of albuminuria) in Edinburgh, and recognized that some cases of eclamptic psychosis occurred without seizures; this explains the interval between seizures (or coma) and psychosis, a gap that has occasionally exceeded 4 days: seizures and psychosis are two different consequences of severe gestosis.
The incidence is about 1 in 1,000 births in Europe and North America, but much higher in India, where large series have been collected. Psychosis is occasionally associated with other arterial or venous lesions: epidural anaesthesia can, if the dura is punctured, lead to leakage of cerebrospinal fluid and subdural haematoma. Arterial occlusion may be due to thrombi, amniotic fragments or air embolism. Postpartum cerebral angiopathy is a transitory arterial spasm of medium caliber cerebral arteries; it was first described in cocaine and amphetamine addicts, but can also complicate ergot and bromocriptine prescribed to inhibit lactation. Subarachnoid haemorrhage can occur after miscarriage or childbirth. All these usually present with neurological symptoms, and occasionally with delirium. Epilepsy
Women with a lifelong epileptic history are liable to psychoses during pregnancy, labour and the puerperium. Women occasionally develop epilepsy for the first time in relation to their first pregnancy, and psychotic episodes have been described. There are over 30 cases in the literature. Hypopituitarism
Pituitary necrosis following postpartum haemorrhage (Sheehans syndrome) leads to failure and atrophy of the gonads, adrenal and thyroid. Chronic psychoses can supervene many years later, based on myxoedema, hypoglycaemia or Addisonian crisis. But these patients can also develop acute and recurrent psychoses, even as early as the puerperium. Water intoxication
Hyponatraemia (which leads to delirium) can complicate oxytocin treatment, usually when given to induce an abortion. By 1975, 29 cases had been reported, of which three were severe or fatal. Urea cycle disorders
Inborn errors of the Krebs-Henseleit urea cycle lead to hyperammonaemia.