Pregnancy in kidney transplantation: satisfactory outcomes and harsh realities

Since the first successful case of a pregnancy reported 40 yrs ago in a woman receiving a kidney transplant from her identical twin sister who did not receive immunosuppressive medications, the dream of a pregnancy in a renal transplant recipient has become reality. In women of childbearing age with a functioning transplant, the pregnancy rate has improved from 2 to 5%. Approximately 35% of pregnancies do not progress beyond the 1st trimester; the success rate is > 90% after the 1st trimester. In this review, different aspects of this topic are discussed: the consequences of pregnancy on renal grafts and maternal morbidity (hemodynamic changes, immunological problems, hypertension/preeclampsia, urinary tract infections and renal damage progression), the influence of renal grafts on pregnancy (perinatal mortality, prematurity, intrauterine growth retardation, low birth weight, malformations, handicaps and immunological problems) and the role of drugs used for renal transplants. A pregnancy can have a successful outcome if pre-conceptional graft function is good, if hypertension is absent and if the interval from grafting is at least 2 yrs. However, the majority of live-born outcomes are premature and many are low birth weight. Recipients must be advised that their offspring can also suffer from immunological abnormalities, malformations, long-term handicaps, and that the deleterious effects of pregnancy on long-term graft function cannot be excluded. In conclusion, women of childbearing age who have had renal transplantation should be counselled before conception about possibility and risks of pregnancy.