Twenty-seven Japanese patients with occlusive thromboaortopathy (Takayasu's disease) associated with 33 pregnancies and deliveries were followed up prospectively, from the prepregnant period. Inflammatory activity of the disease was apparently not enhanced by the pregnancy, but various cardiovascular-related events occurred in the perinatal period. During the intrapartum uterine contractions, marked elevation of systolic blood pressure was associated with 10 pregnancies, including 1 case of subsequent cerebral hemorrhage; this did not occur in 13 normal control gravidas. There were no maternal or neonatal deaths. The birth weight of 25 infants of 21 patients without complications or with a mild single complication of Takayasu's disease was 3,023 +/- 442 g (mean +/- standard deviation). The birth weight of 8 infants of 6 patients who had a severe single complication or multiple complications of the disease was 2,599 +/- 394 g (p less than 0.05). Of 83 pregnancies, the present 33 plus 50 other reported cases there were no un-toward events in two fifths. Three fifths had various problems, most of which were related to pressure elevation and heart failure, including intrapartum cerebral hemorrhage in 4. These data should assist in predicting the outcome of pregnancy and delivery in patients with Takayasu's disease.