Critically ill pregnant and postnatal women admitted to intensive care units (ICUs) require highly specialised care, components of which many critical care nurses are unfamiliar with. There are no specialist critical care obstetric centres in Australia, with critically ill obstetric patients admitted to general ICUs. There are no published guidelines and little research that assist critical care nurses to care for such women. Furthermore, the admission of pregnant or postnatal women to ICUs is likely to increase with emerging childbearing patterns in Australia. It is therefore timely to review what we know about caring for critically ill pregnant and postnatal women. This paper analyses the literature on intensive care utilisation by obstetric patients and provides an overview regarding which pregnant and postpartum women require intensive care. The key areas of providing mechanical ventilation to pregnant women and assessment of fetal wellbeing are explored in detail. The most frequent conditions and their treatment, preeclampsia and obstetric haemorrhage, are also reviewed. The establishment of lactation is also considered as the critical care nurse is commonly involved in supporting the woman's endeavour to breastfeed.