PREGNANCY IN CHRONIC DIALYSIS - A REVIEW AND ANALYSIS OF THE LITERATURE

Pregnancy is uncommon in end-stage renal failure, particularly in pati ents requiring dialysis. We reviewed the literature from 1965 to date, seeking an optimal way of dialyzing pregnant women after encountering one such patient. Methods. We searched the English literature by cros s-referencing ''pregnancy'' with ''hemo-'' or ''peritoneal dialysis'' and ''renal failure''. Eighty-six pregnancies worldwide were found to which we added one case of our own. Various independent factors were s tudied against gestational age at delivery using uni- and multivariate analysis. These factors included mother's age, previous delivery diag noses of renal disease, dialysis duration prior to pregnancy; gestatio nal age at onset of dialysis, dialysis type, level of hemoglobin durin g pregnancy BUN and creatinine targets, BUN/creatinine ratio, dialysis intensity at the beginning and end of pregnancy, influence of erythro poietin and dialysis complications. Results. Of the 87 pregnancies, 12 % resulted in stillbirths, 9% of neonates died prior to discharge. The mean gestational age at delivery was 32 +/- 5 weeks, and the mean bir th weight 1604 +/- 652 g. Two congenital abnormalities and one twin pr egnancy were reported. 48% of deliveries were premature. Pre-eclampsia was reported in 11%, and worsening hypertension in 17%. CAPD was used in 25 and hemodialysis in 62 patients. Fetal survival was similar in both cases (72% vs 82%), although incidence of various dialysis compli cations differed. The conventional dialysis goals of a low target BUN level and hemoglobin for pregnant patients were not factors in predict ing fetal outcome. The number of hemodialyses/week were negatively cor related (R = -0.35 P = 0.061), but the hours of dialysis positively co rrelated (R = 0.42, p = 0.035) to gestational age. Fetal survival was independently influenced by creatinine level [564 mu mol/L when baby s urvived vs 788 mu mol/L when baby died (p = 0.021)], BUN/creatinine ra tio (50 vs 30 p = 0.053), and hours of dialysis (5.6 hrs vs 3.6 hrs, p =0.013). There was no relation of either frequency or volume of perito neal dialysis exchanges to gestational age or fetal survival. Conclusi ons. Greater attention to a high intake of protein (>1.5 g/kg) and hig her dose of hemodialysis, achieved by longer, every other day dialysis , may be the optimal approach to pregnant patients on hemodialysis. Ou r first attempt to define the goal of hemodialysis is to keep the pred ialysis creatinine below 600 mmol/L and the protein intake high enough so the predialysis BUN level is >25 mmol/L. There are no clear guidel ines on how to best perform CAPD.