In 1992 we published a case-controlled study of posttransplant follow-up in 36 renal allograft recipients (Am J Kidney Dis 19:167-172, 1992). Eighteen of these patients became pregnant and comprise the index group; the 18 patients who did not become pregnant were considered controls. By the end of the follow-up period, plasma creatinine in the index group and controls had increased by 19% and 8%, respectively. Graft loss or chronic rejection occurred in one patient in the index group and in two in the control group. As there were no significant differences between the two groups, we concluded that pregnancy was unlikely to have a major effect on long-term graft function and/or survival. Subsequently, a case control study of Finnish women demonstrated graft survival favoring women who never conceived versus those who did (69% v 100%, respectively; P < 0.005) and thus prompted us to extend our posttransplant follow-up by a further 3 years. Data are currently available for 17 index subjects and 17 controls and during the entire follow-up period, graft losses have occurred in one index subject and in four controls. Plasma creatinine at the end of the follow-up period (1.40 +/- 0.52 mg/dL and 1.54 +/- 0.95 mg/dL, respectively) had increased from 3 years earlier by 11% and 7%, respectively, increments across time that were not significant. Although the increase in plasma creatinine was greater in the index subjects compared with the controls, there were no significant differences between the two groups. While our data do not exclude a minor deleterious effect of pregnancy on long-term graft function, we believe that female allograft recipients can be reassured that pregnancy is unlikely to substantially alter long-term graft function.