Assessment of Obstetric and Kidney Outcomes in Women Who Underwent Hemodialysis during Pregnancy in Brazil

Background: Pregnant women with renal disease have worse obstetric outcomes than their healthy pairs, and risks are greater when dialysis is needed. Our main goal is to analyze maternal, fetal and renal outcomes of pregnant women who performed hemodialysis (HD) sessions due to acute kidney injury (AKI) or chronic kidney disease (CKD) during their hospital stay. Methods: Single center retrospective observational study conducted to assess the features of pregnant women with CKD or AKI who needed HD and were followed by the Nephrology department of UNIFESP-EPM during the years between 2005-2019. These patients were compared between each other and sorted in three groups: AKI, non-dialytic CKD (NDCKD) and end-stage renal disease (ESRD). Results: Our sample consisted of 36 pregnant women. Overall, 10 (27.8%) women presented with AKI, 14 (38.9%) with NDCKD and 12 (33.3%) with ESRD. Demographic data were similar between the groups, with a mean age of 30,7 years. All of the women in the AKI group dialyzed in the puerperium, while all the women in de NDCKD group started dialysis during pregnancy, with 69.2% starting in the 2nd trimester, and 60% of the ESRD women increased their dialysis schedule in the 1st trimester. Preeclampsia was more common in patients with AKI (50%) comparing to patients with NDCKD (27.3%) or with ESRD (no cases described). Furthermore, 4 patients (40%) in the AKI cohort evolved to death and no patients in the CKD groups. Regarding the live birth rate, we found a 60% rate in the AKI group, 57.1% in the NDCKD group and 58.3% in the ESKD women. Concerning the prematurity, there was a 66.7% frequency in the AKI patients, 87.5% in the NDCKD women and 85.3% in the ESKD group, considering only the live newborns. In the three groups, we did not find any statistical difference concerning the fetal outcomes. In our research, the weekly dialysis time were related only to the birth weight of the newborns, in a way that, the longer the weekly dialysis time, the greater the birth weight (p = 0.037). Conclusion: Pregnant women with AKI needed dialysis later (in the puerperium) and had greater mortality. The negative pregnancy outcomes were similar between the three groups and worse than the general Brazilian population. The longer weekly dialysis schedule was related to greater birth weight.