Racial Differences and Factors Associated with Pregnancy in ESKD Patients on Dialysis in the United States

Background Pregnancy in women with ESKD undergoing dialysis is uncommon due to impaired fertility. Data on pregnancy in women on dialysis in the United States is scarce. Methods We evaluated a retrospective cohort of 47,555 women aged 15-44 years on dialysis between January 1, 2005 and December 31, 2013 using data from the United States Renal Data System with Medicare as primary payer. We calculated pregnancy rates and identified factors associated with pregnancy. Results In 47,555 women on dialysis, 2352 pregnancies were identified. Pregnancy rate was 17.8 per thousand person years (PTPY) with the highest rate in women aged 20-24 (40.9 PTPY). In the adjusted time-to-event analysis, a higher likelihood of pregnancy was seen in Native American (HR, 1.77; 95% CI, 1.33 to 2.36), Hispanic (HR, 1.51; 95% CI, 1.32 to 1.73), and black (HR, 1.33; 95% CI, 1.18 to 1.49) women than in white women. A higher rate of pregnancy was seen in women with ESKD due to malignancy (HR, 1.64; 95% CI, 1.27 to 2.12), GN (HR, 1.38; 95% CI, 1.21 to 1.58), hypertension (HR, 1.32; 95% CI, 1.16 to 1.51), and secondary GN/vasculitis (HR, 1.18; 95% CI, 1.02 to 1.37) than ESKD due to diabetes. A lower likelihood of pregnancy was seen among women on peritoneal dialysis than on hemodialysis (HR, 0.47; 95% CI, 0.41 to 0.55). Conclusions The pregnancy rate is higher in women on dialysis than previous reports indicate. A higher likelihood of pregnancy was associated with race/ethnicity, ESKD cause, and dialysis modality.