Pregnancy in the renal transplant patient.

I N THIS ISSUE of American Journal of Kidney Diseases, Sturgis and Davison compare, in case control fashion, the long-term renal prognosis of 18 women who underwent 34 pregnancies after kidney transplantation with 18 allograft recipients who never conceived. Posttransplant follow-up in each group averaged 12 years, and the mean time that elapsed from the first pregnancy was 5 years. The authors found no statistical differences in glomerular filtration rate (GFR) (measured by inulin infusion) or prevalence of hypertension between those who conceived and those who did not, concluding, cautiously, that pregnancy had no remote adverse effect on either renal function or blood pressure in these allograft recipients. One might argue that their pairing was a bit imperfect, the number of patients was limited, and the failure to find differences may reflect type II errors, in that studying more patients might show a small but significant adverse effect of childbearing on renal function. However, to our knowledge these data are currently unique and are encouraging to allograft recipients who want to bear children. As noted by Sturgis and Davison and reviewed elsewhere,I,2 renal transplantation is accompanied by a striking improvement of reproductive function, including a reversal of the relative infertility that accompanies end-stage renal disease, so that conception rates estimated at less than 1 in 200 for dialysis patients increase to 1 in 50. Regretfully, however, many of these pregnancies were not planned, the allograft recipients being unaware that they could conceive, and therefore some sought prenatal care for such "high risk" pregnancies quite late in gestation. Thus, we begin this editorial by underscoring the importance of contraceptive counseling for all renal patients of childbearing age, including transplant recipients. This is a responsibility nephrologists too often neglect. How should we counsel these women? First, physicians should be aware that many aspects of kidney disease and pregnancy are controversial, and transplantation is no exception. For example, in a 1985 editorial in this journal we served as arbitrators of two discordant views concerning the renal and pregnancy prognosis in women with primary glomerular disease who conceive, and these controversies surfaced again in later issues of the Journal. 4,5 Some saw nefarious results when gestation and kidney disease coexisted, especially in the case of certain specific disorders; whereas others, including ourselves, argue that it is the functional status and presence or absence of hypertension that determine outcome. That is, if GFR is well preserved (serum creatinine < 130 ~mol/L [1.5 mg/dLD and the patient normotensive, over 95% ofthe gestations will be successful, and only a minority will experience acceleration of their disease. Our conclusions were based on information from over 1,000 patients with biopsy-diagnosed renal diseases, but the data are primarily retrospective and correlative in nature. The circumstances are similar for transplantation, some suggesting guarded results both for fetus and allograft,6 whereas others are substantially more optimistic. 1,2 Again, the principle that renal function and presence or absence of hypertension determine outcome appears to prevail in this category as well. Substantiating this view, Dr Davison, coauthor of the article in this issue, has periodically provided us with surveys of the literature, which unfortunately consists primarily of case reports and small retrospective series. In his most recent review, which appeared in the February 1991 issue ofthisjournaV he surveyed 2,309 gestations in 1,594 allograft recipients and noted that 40% of the pregnancies did not go beyond the first trimester. The number of spontaneous abortions was similar to that in the population at large (approximately 16%); the remaining terminations ("therapeutic") were