The obstetric and perinatal outcome in 51 oocyte donation pregnancies (61 infants) was compared with that of a control group of standard in-vitro fertilization (IVF) patients (97 pregnancies, 126 infants). The oocyte recipients (mean +/- SD age 33.5+/-4.7 years) included 39 women with ovarian failure and 12 women with functioning ovaries. In oocyte recipients, first trimester bleeding (53%) occurred significantly more often than in IVF mothers (31%, P < 0.01). Pregnancy-induced hypertension was observed in 31% of oocyte recipients compared with 14% in IVF mothers (P < 0.05). There was no difference in the duration of pregnancies or in the preterm delivery rate between the two groups. When restricting analysis to singleton pregnancies, 63% of oocyte recipients were hospitalized in the antenatal period compared with 29% in the IVF group (P < 0.001). The Caesarean section rate was 57% in the oocyte donation group and 37% in the IVF group (P < 0.05). Birthweight in singleton pregnancies was similar in both groups. The perinatal mortality rate was 3.3% in the oocyte donation group and 0% in the IVF group. In conclusion, oocyte donation pregnancies are associated with an increased risk compared with IVF pregnancies, but the complications are usually manageable and most oocyte recipients experience a good pregnancy outcome.