What are the indications for dialysis in pregnancy?

From the Guidelines

Dialysis in pregnancy is indicated for women with end-stage renal disease (ESRD) who become pregnant or for pregnant women who develop acute kidney injury (AKI) with severe complications, and should receive long frequent hemodialysis, typically 20-24 hours weekly or 4-6 sessions per week, aiming for pre-dialysis BUN levels below 50 mg/dL. The primary indications for dialysis in pregnancy include uremic symptoms (nausea, vomiting, encephalopathy), refractory hyperkalemia (potassium >6.0 mEq/L), severe metabolic acidosis (pH <7.2), volume overload unresponsive to diuretics, and BUN levels exceeding 100 mg/dL 1. For pregnant women with pre-existing ESRD, more intensive dialysis regimens are recommended, as they improve maternal and fetal outcomes by better controlling uremic toxins, electrolytes, and fluid status 1.

Key Considerations

• Uremic symptoms, such as nausea, vomiting, and encephalopathy, are indications for dialysis in pregnancy 1
• Refractory hyperkalemia (potassium >6.0 mEq/L) and severe metabolic acidosis (pH <7.2) require prompt initiation of dialysis 1
• Volume overload unresponsive to diuretics and BUN levels exceeding 100 mg/dL are also indications for dialysis in pregnancy 1
• Long frequent hemodialysis, either in-center or at home, is recommended for pregnant women with ESRD, depending on convenience 1

Dialysis Regimen

• Long frequent hemodialysis, typically 20-24 hours weekly or 4-6 sessions per week, is recommended for pregnant women with ESRD 1
• The goal is to achieve pre-dialysis BUN levels below 50 mg/dL, which improves maternal and fetal outcomes 1
• Hemodialysis is generally preferred over peritoneal dialysis in pregnancy, with careful attention to avoid hypotension, maintain adequate nutrition, and adjust medications as needed 1

From the Research

Indications for Dialysis in Pregnancy

• The decision to initiate dialysis in pregnant women with chronic kidney disease (CKD) is influenced by several factors, including the severity of CKD, presence of symptoms, and laboratory trajectories 2, 3.
• Women with severe CKD (eGFR < 30 mL/min) may experience a reduced rate of pre-eclampsia and longer gestation with earlier initiation of dialysis 2.
• Persistent signs and symptoms of uremia, volume overload, worsening eGFR, metabolic acidosis, and hyperkalemia inform the timing of therapy initiation 3.
• There is no recommended estimated glomerular filtration rate (eGFR) threshold for initiating dialysis, and patient-clinician shared decision-making should help determine when to initiate dialysis 3.

Considerations for Dialysis Modality

• The two dialysis modalities are peritoneal dialysis and hemodialysis, with no differences in long-term mortality rates between the two modalities 4, 5.
• Peritoneal dialysis is performed at home, while hemodialysis is typically performed at a dialysis center through vascular access 4.
• Hemodialysis has a late survival advantage over peritoneal dialysis, with antecedent hypoalbuminemia being a major marker of the increased late mortality in peritoneal dialysis patients 5.

Management of Complications

• Treatment of patients with advanced chronic kidney disease or end-stage renal disease includes management of complications, such as hyperkalemia, hypervolemia, metabolic acidosis, anemia, mineral and bone disorders, and protein-calorie malnutrition 4, 6.
• Patients with end-stage renal disease on maintenance dialysis have a high risk of developing hyperkalemia, and management strategies include dialysis, dietary potassium restriction, and avoidance of medications that increase hyperkalemia risk 6.