The effects of pregnancy on the course of Behçet's disease (BD), and vice versa, are unknown and little has been reported. We have studied three groups of women: (1) group A included 61 pregnancies in 23 women with BD, 25 pregnancies took place in 10 patients already diagnosed (group 1A) and 36 pregnancies occurred in 13 patients before disease diagnosis (group 2A); (2) group B included 30 females with 83 pregnancies affected by recurrent oral ulcers (ROU); (3) group C included 20 healthy women with 61 pregnancies. We investigated the effects of BD on pregnancy and fetal outcome, and the influence of gestation on the course of BD. A questionnaire was used in which specific information about each pregnancy, labour and puerperium was collected. We looked for medical confirmation in all cases where any pathology had been identified. No significant differences were found in the incidence of pregnancy complications between groups. The incidence of perinatal death was also similar and neither congenital abnormalities nor neonatal BD were observed. Only two patients observed a flare of the disease and in two cases the diagnosis of BD was made during the pregnancy. In our series, the outcome of pregnancy was generally good in BD patients, disease manifestations were not consistently worsened and fetal outcome was excellent. The first case of Budd-Chiari syndrome during the puerperium in a BD patient is reported.