Eclampsia is a serious consequence of pre-eclampsia. There are limited data from Australia and New Zealand (ANZ) on eclampsia.

To determine the incidence, management and perinatal outcomes of women with eclampsia in ANZ.

A two-year population-based descriptive study, using the Australasian Maternity Outcomes Surveillance System (AMOSS), carried out in 263 sites in Australia, and all 24 New Zealand maternity units, during a staggered implementation over 2010-2011. Eclampsia was defined as one or more seizures during pregnancy or postpartum (up to 14 days) in any woman with clinical evidence of pre-eclampsia.

Of 136 women with eclampsia, 111 (83%) were in Australia and 25 (17%) in New Zealand. The estimated incidence of eclampsia was 2.2 (95% confidence interval (CI) 1.9-2.7) per 10 000 women giving birth. Aboriginal and Torres Strait Islander women were over-represented in Australia (n = 9; 8.1%). Women with antepartum eclampsia (n = 58, 42.6%) were more likely to have a preterm birth (P = 0.04). Sixty-three (47.4%) women had pre-eclampsia diagnosed prior to their first eclamptic seizure of whom 19 (30.2%) received magnesium sulphate prior to the first seizure. Nearly all women (n = 128; 95.5%) received magnesium sulphate post-seizure. No woman received prophylactic aspirin during pregnancy. Five women had a cerebrovascular haemorrhage, and there were five known perinatal deaths.

Eclampsia is an uncommon consequence of pre-eclampsia in ANZ. There is scope to reduce the incidence of this condition, associated with often catastrophic morbidity, through the use of low-dose aspirin and magnesium sulphate in women at higher risk.