Twenty-two renal transplant recipients had 29 post-transplant pregnancies and 39 male transplant recipients became fathers to 65 children between 1971 and 1991. Of the deliveries of the female patients, 62% took place between the third and sixth year after transplantation. Seven patients had 2 pregnancies. Mean follow-up time after the first posttransplant pregnancy was 7.5 years. The patients survived the pregnancy well, but the increase in serum creatinine concentration from the prepregnancy level, registered 3 months and 1 year after delivery, was higher than in matched control patients without pregnancy at corresponding times after transplantation (the increase in serum creatinine was 47.7 and 61.2 μmol/L in the pregnant patients versus −2.7 and 5.4 μmol/L in the control patients, P<0.0001 and P<0.02, respectively). All pregnant and control patients were alive at the end of follow-up, but the long-term graft survival of those with a pregnancy was significantly (P<0.005) worse than in the control patients. Ten-year graft survival was 69% in the pregnant versus 100% in the control patients. Although 80% of the neonates born to a mother with a transplanted kidney were below the mean for gestational age, the weight and length at birth were within normal limits and no severe intrauterine growth retardation was documented.