Five cases of pregnancy occurring in three women with previously diagnosed Wegener's granulomatosis are described. The disease was diffuse in one case and localised in the other. Initial treatment consisted of a combination of corticosteroids and intravenous cyclophosphamide in two women, and methotrexate in one. Four pregnancies ended in live births despite pre-eclampsia in two cases. One therapeutic abortion was induced because of encephalocele. Comparable reported cases were reviewed to examine the implications of immunosuppressive treatment on the fetus. A relapse occurred during pregnancy in 40% of the cases, but in 25% if only pregnancies beginning during inactive disease were taken into account. No other indicator for maternal and fetal outcome was obvious. Pregnancy should be planned after complete disappearance of disease activity. In the case of a relapse a combination of immunosuppressive drugs and corticosteroids should be chosen rather than corticosteroids alone because the outcome of pregnancy is poor in cases of undertreatment. Prematurity remains common.