Pregnancy in women receiving renal dialysis or transplantation in Japan: anationwide survey

Background. Since a report on the first successful pregnancy of a woman on long-term haemodialysis in Japan in 1977, there has been a growing number o f case reports on successful pregnancy in patients on dialysis. We undertoo k a nationwide survey on pregnancy in women on renal replacement therapy in 1996. Methods, A preliminary questionaire was sent to 2504 dialysis units and 143 renal transplant units in Japan. For each reported pregnancy, a more detai led questionaire was sent to collect nephrological, obstetric and neonatal information. Results. There were 172 pregnancies (0.44%) reported in 38889 women on dial ysis, with 90 successful pregnancies (0.23%), and 194 pregnancies reported in 852 female renal transplant recipients. Detailed pregnancy information w as collected from 74 women on dialysis and 194 renal transplant recipients. Of the 74 pregnancies in the women on dialysis, 36 (48.6%) resulted in sur viving infants, nine (12.2%) in neonatal death, nine (12.2%) spontaneous ab ortions and 14 (18.9%) elective abortions were reported. The outcome of six pregnancies (8.1%) was unknown. Of 194 pregnancies in renal transplant rec ipients, 159 (82.0%) resulted in surviving infants, two (1.4%) in neonatal death and 28 (14.4%) in spontaneous or elective abortion. In five cases the pregnancy outcome was not reported. No congenital anomalies were reported, except two infants with mental retardation and one with epilepsy. Conclusion, The current survey revealed that the rate of successful pregnan cy in women on dialysis has improved. More than half of the pregnancies res ulted in infant survival. But, premature birth is a major problem for the c hildren of women on dialysis and there is a higher rate of neonatal death. There are significant differences in gestational age, birth weight, frequen cy and severity of prematurity and rates of neonatal death between pregnanc ies of women undergoing dialysis and those who are renal transplant recipie nts.