When is peritoneal dialysis (PD) more beneficial than hemodialysis (HD) for a pregnant patient with end-stage renal disease (ESRD)?

When Peritoneal Dialysis May Be Beneficial Over Hemodialysis in Pregnant ESRD Patients

Peritoneal dialysis is rarely the preferred modality in pregnancy with ESRD, as hemodialysis—particularly intensive hemodialysis (≥36 hours/week)—has emerged as the superior approach with better live birth rates and gestational outcomes. However, PD may be considered in specific circumstances where intensive HD is not feasible or accessible.

Primary Recommendation: Intensive Hemodialysis is Preferred

The evidence strongly favors intensive hemodialysis over peritoneal dialysis for pregnant women with ESRD:

• Intensive HD (>36 hours/week) achieves live birth rates of 85-89% with mean gestational age of 36 weeks, compared to conventional HD (50-87% live birth rates, median 27 weeks gestation) 1, 2

• A clear dose-response relationship exists: live birth rates are 48% with ≤20 hours/week HD, 75% with 30 hours/week, and 85% with >36 hours/week 1, 2

• Women on PD have lower and static live birth rates over time compared to improving outcomes with HD 3

• Infants born to mothers on PD are more likely to be small for gestational age compared to those on HD, despite similar preterm delivery rates 3

Limited Circumstances Where PD May Be Considered

1. When Intensive HD is Not Accessible

• If the patient lacks access to a dialysis center offering 6-times-weekly or nocturnal HD programs 4
• In geographic areas where intensive HD infrastructure is unavailable 4
• When home HD is not feasible due to lack of caregiver support or home environment limitations 1

2. Hemodynamic Instability with HD

• PD offers hemodynamic advantages with continuous, gentle fluid removal that may be better tolerated than intermittent HD in patients with severe cardiovascular instability 5
• Avoids rapid fluid shifts that can compromise placental-fetal blood flow (HD ultrafiltration should be kept <6-8 mL/kg/hour) 6

3. As a Supplemental Strategy

• PD can be combined with intermittent HD to achieve adequate dialysis intensity when either modality alone is insufficient 4
• This hybrid approach allows for continuous clearance via PD while supplementing with HD sessions to reach target weekly clearance 4

4. Patient Already Established on PD Pre-Pregnancy

• If a woman conceives while already on PD with good catheter function and adequate clearance 5, 7
• However, transition to intensive HD should still be strongly considered given superior outcomes 3

Critical Technical Considerations if PD is Used

Dialysis Prescription Adjustments

• Increase dialysate volumes and exchange frequency to compensate for reduced efficiency compared to intensive HD 7
• In the third trimester, uterine enlargement may require higher delivered automated PD volumes to maintain adequate clearance 7
• **Target predialysis creatinine <600 μmol/L** and maintain high protein intake (>1.5 g/kg) to keep predialysis BUN >25 mmol/L 8

Monitoring Requirements

• Close monitoring of catheter function as uterine enlargement can negatively affect catheter performance and prescribed dwell volumes 7
• Regular assessment of adequacy with more frequent Kt/V measurements 7
• Consider hospitalization in third trimester to facilitate delivery of increased dialysate volumes and limit activity 7

Major Limitation of PD

• PD has lower efficiency in removing solutes (uric acid, urea) and electrolytes (potassium, phosphate) compared to HD and continuous renal replacement therapies 1
• No clear correlation exists between frequency/volume of PD exchanges and gestational age or fetal survival, unlike the clear dose-response seen with HD hours 8

Common Pitfalls to Avoid

• Do not continue conventional thrice-weekly HD or standard PD prescriptions in pregnancy—both are inadequate 2, 6
• Do not assume PD and HD are equivalent options—the evidence clearly favors intensive HD for maternal and fetal outcomes 3
• Do not delay transition from PD to intensive HD if the latter becomes available, as this represents the optimal modality 3
• Avoid attempting to restrict fluid intake in pregnant PD patients to reduce ultrafiltration needs, as this risks inadequate nutrition and fetal growth 6

Bottom Line Algorithm

For any pregnant woman with ESRD:

1. First choice: Intensive HD (≥36-48 hours/week, typically 6 nights/week) 1, 2
2. Consider PD only if: Intensive HD is truly inaccessible, severe hemodynamic instability precludes HD, or as a supplement to intermittent HD 4, 5
3. If PD is used: Maximize prescription intensity, monitor closely, hospitalize in third trimester if needed, and remain prepared to transition to HD 7
4. Target outcomes: BUN <35 mg/dL, adequate nutrition, and close obstetric monitoring regardless of modality 2, 8