In developed countries, the rate of obstetric ICU admissions (admission during pregnancy or the postpartum period) is between 0.5 and 4 per 1000 deliveries and the overall case-fatality rate is about 2%. The most two common causes of obstetric ICU admissions concerned direct obstetric pathologies: obstetric hemorrhage and hypertensive disorders of pregnancy. This review summarized the principles of management of critically ill pregnant patient. Its imply taking care of two patients in the same time. A coordinated multidisciplinary team including intensivists, anesthesiologists, obstetricians, pediatricians and pharmacists is therefore necessary. This team must work effectively together with regular staff aiming to evaluate daily the need to maintain the patient in intensive care unit or to prompt delivery. Keeping mother and baby together and fetal well-being must be balanced with the need of specialized advanced life support for the mother. The maternal physiological changes imply various consequences on management. The uterus aorto-caval compression implies tilting left the parturient. In case of cardiac arrest, uterus displacement and urgent cesarean delivery are needed. The high risk of aspiration and difficult tracheal intubation must be anticipated. Even during acute respiratory distress syndrome, hypoxemia and permissive hypercapnia must be avoided due to their negative impact on the fetus. Careful analysis of the benefit-risk ratio is needed before all drug administration. Streptococcal toxic shock syndrome and perineal fasciitis must be feared and a high level of suspicion of sepsis must be maintained. Finally the potential benefits of an ultrasound-based management are detailed.