Intensive care in obstetrics: an evidence-based review.

The necessity for critical care support and admission to an intensive care unit (ICU) is a relatively infrequent occurrence during pregnancy and the postpartum period. The exact incidence is unclear because of the variety of reporting methods and definitions, with estimates that range from 0.17% to 1.1% of pregnant patients. All of the published series to date are small; the largest series includes 131 obstetric critical care patients. Zeeman et al described their experience with 483 patients who were treated in an obstetric intermediate care unit. This series represented 1.7% of deliveries during a 2-year period, which is a substantially higher rate than reported in other studies. This high percentage likely reflects the inclusion of some patients with lower acuity who were admitted for ‘‘intermediate care’’ who otherwise would not have required transfer to a traditional ICU. Of the 34 patients who were transferred to the ICU, most patients (71%) required ventilatory support. Obstetric complications account for most ICU admissions in pregnant patients, which range from 47% to 93%. Hemorrhage and hypertensive disorders (primarily preeclampsia and eclampsia) constitute most