Acute aortic dissection is a life-threatening disease. To increase the awareness of this diagnosis as a cause of feto-maternal mortality during pregnancy, we have analyzed risk factors using information from five pregnant women admitted for acute aortic dissection to the Karolinska University Hospital over an eight-year period (1999-2007). Four of the women died and only one survived. One fetus was stillborn and all newborn infants showed signs of asphyxia at birth. Of the women, who were on average five years above the mean age for delivery in Sweden, three had hypertension, two had first-degree relatives with aortic dissection which had occurred during the second half of pregnancy (gestational age at diagnosis 26-41 weeks). The most common presenting symptoms were severe back, abdominal and leg pain, and confusion. If a rapid diagnosis is not made, the risk of mortality for both mother and fetus is high. The incidence of aortic rupture during pregnancy in Sweden appears to be 14.5/1,000,000 and the case maternal fatality ratio 4.4/1,000,000.