Pregnancy in renal allograft recipients: problems, prognosis and practicalities.

Improvements in reproductive function invariably follow renal transplantation. The possibility of conception in women of childbearing age emphasizes the need for compassionate and comprehensive counselling. Couples who want a child should be encouraged to discuss all the implications. Therapeutic abortion is undertaken in 20% of conceptions and the spontaneous abortion rate is about 14%, the same as for the normal population. Of the conceptions that continue beyond the first trimester, 93% end successfully. In most women, renal function is augmented during pregnancy, but permanent impairment occurs in 15% of pregnancies. In others there may be transient deterioration in late pregnancy (with or without proteinuria). There is a 30% chance of developing hypertension, pre-eclampsia or both. Preterm delivery occurs in 45-60%, and intrauterine growth retardation in at least 20% of pregnancies. Despite its pelvic location, the transplanted kidney rarely produces dystocia and is not injured during vaginal delivery. Caesarean section should be reserved for obstetric reasons only. Neonatal complications include respiratory distress syndrome, leucopenia, thrombocytopenia, adrenocortical insufficiency and infection. No predominant or frequent developmental abnormalities have been described and data on infancy and childhood are encouraging. Future clinical and laboratory research needs to focus on improving prepregnancy assessment criteria, better understanding of the mechanisms of gestational renal dysfunction, proteinuria and the rare, but devastating, accelerated rejection, assessing the side-effects and implications of immunosuppression in pregnancy and learning more about the remote effects of pregnancy on both renal prognosis and the offspring.