Background and objectives: Women of childbearing age on conventional hemodialysis (CHD) have decreased fertility when compared with the general population. Even in women who conceived, maternal morbidity and fetal mortality remained elevated. We hypothesized that nocturnal hemodialysis (NHD) (3 to 6 sessions per week, 6 to 8 h per treatment), by augmenting uremic clearance, leads to a more hospitable maternal environment and therefore superior outcomes in fertility and pregnancy compared with CHD.
Design, setting, participants, and measurements: This is a descriptive cohort study of all female patients achieving pregnancy and delivering a live infant while on NHD at the University Health Network, St. Michael's Hospital, and Humber River Regional Hospital from 2001 to 2006 in Toronto, Canada. Our primary objective was to describe maternal and fetal outcomes in addition to the changes in biochemical parameters after conception in our cohort.
Results: Our cohort included five patients (age range, 31 to 37 yr) who had seven pregnancies while on NHD and delivered six live infants. All had previously been on CHD, but none conceived during that time. In all patients, the amount of hemodialysis was increased (from a weekly mean of 36 +/- 10 to 48 +/- 5 h; P < 0.01) after pregnancy was diagnosed. Mean predialysis blood urea and mean arterial BP were maintained within normal physiological parameters. The mean gestational age of the cohort was 36.2 +/- 3 wk and the mean birth weight was 2417.5 +/- 657 g. The maternal and fetal complications observed in the cohort included intrauterine growth restriction or small for gestational age (n = 2), preterm delivery (<32 wk) (n = 1), and shortened cervix threatened labor (n = 1). Anemia was accentuated during pregnancy, and intravenous iron and erythropoietin requirements were increased. To maintain normal physiological indices for plasma phosphate, an augmented dialysate phosphate supplementation regimen was required.
Conclusions: NHD may allow for improved fertility. Delivering a live infant at a mature gestational age is feasible for patients on NHD. Our cohort tended to have fewer maternal and fetal complications compared with historical controls. Hemoglobin and phosphate levels must be monitored with treatment adjusted accordingly.