How to manage nephrotic syndrome in a 16-week pregnant woman?

Management of Nephrotic Syndrome in a 16-Week Pregnant Woman

Coordinate care immediately between nephrology and obstetrics, continue pregnancy with close monitoring while implementing supportive management focused on edema control, thromboprophylaxis, and infection prevention, as termination is not indicated at 16 weeks unless severe maternal complications develop. 1

Initial Assessment and Risk Stratification

Determine if this is new-onset nephrotic syndrome or pre-existing disease, as this fundamentally changes management and prognosis:

• New-onset nephrotic syndrome at 16 weeks requires urgent evaluation to exclude preeclampsia (though uncommon this early), secondary causes (lupus, infections), and primary glomerular disease 2, 3
• Obtain comprehensive workup: 24-hour urine protein, serum albumin, creatinine, lipid panel, complete blood count 3
• Screen for secondary causes: ANA, complement levels (C3, C4), hepatitis B/C, HIV, anti-dsDNA if lupus suspected 4
• Consider renal biopsy if diagnosis remains unclear and management would change, particularly if proteinuria is severe, hematuria present, or renal function declining 5, 6
• Assess baseline renal function carefully, as serum creatinine >1.4 mg/dL predicts worse maternal and fetal outcomes 3

Supportive Management: The Foundation of Treatment

Edema and Volume Management

Restrict dietary sodium to <2-3 g/day as first-line therapy for edema control 1, 4:

• Initiate furosemide 0.5-2 mg/kg per dose orally, up to six times daily (maximum 10 mg/kg/day) based on edema severity 1, 4
• Avoid furosemide doses >6 mg/kg/day for >1 week due to ototoxicity risk 1, 4
• Consider adding thiazide diuretic for synergistic effect if loop diuretics alone insufficient 4
• Use albumin infusions only if clinical signs of hypovolemia present (oliguria, prolonged capillary refill, tachycardia, hypotension), not based solely on serum albumin levels 7, 4

Thromboprophylaxis

Initiate prophylactic anticoagulation if serum albumin <20-25 g/L, as pregnancy itself increases thrombotic risk 5-fold and nephrotic syndrome compounds this dramatically 4:

• Low-molecular-weight heparin is preferred over warfarin in pregnancy
• Continue low-dose aspirin (≤100 mg/day) started before 16 weeks gestation to reduce preeclampsia risk 1
• Monitor for thrombotic complications closely during acute illness or immobilization 7

Infection Prevention and Management

Maintain high index of suspicion for bacterial infections, as these are a major cause of maternal mortality in nephrotic syndrome 7:

• If fever develops, obtain blood cultures and start empirical broad-spectrum antibiotics immediately without waiting for results, targeting encapsulated organisms 7
• Consider IVIG infusion if plasma IgG levels low and patient has severe/recurrent infections 7
• Update vaccination status, though live vaccines contraindicated in pregnancy

Immunosuppressive Therapy Considerations

Safe immunosuppressive options during pregnancy include glucocorticoids, hydroxychloroquine, azathioprine, tacrolimus, and cyclosporine 1:

• If biopsy shows minimal change disease, consider prednisone 1 mg/kg/day 4
• For focal segmental glomerulosclerosis, calcineurin inhibitors (tacrolimus or cyclosporine) are first-line 4
• Absolutely avoid cyclophosphamide (teratogenic) and mycophenolate (highly teratogenic) - if patient on mycophenolate, switch to azathioprine immediately 1
• Hydroxychloroquine should be continued if already prescribed, as withdrawal increases flare risk 1

Monitoring Protocol

Establish intensive monitoring schedule given high-risk nature 3, 8:

• Weekly visits with blood pressure, weight, proteinuria assessment
• Monitor serum creatinine, albumin, electrolytes every 1-2 weeks initially 4
• Serial fetal growth ultrasounds every 2-3 weeks starting at 20 weeks, as intrauterine growth restriction common 6, 8
• Antenatal testing (non-stress tests, biophysical profiles) starting at 28-32 weeks
• Watch for progressive renal dysfunction - 3 of 11 patients in one series required dialysis 3

Delivery Planning

Plan for delivery at tertiary center with neonatal intensive care unit, as mean gestational age at delivery is 34 weeks 3:

• Expect preterm delivery in most cases (30-38 weeks typical) 3, 8
• Timing depends on maternal renal function, proteinuria severity, fetal growth, and development of complications
• Membranous nephropathy has better maternal-fetal prognosis than FSGS, MPGN, or minimal change disease 8

Critical Pitfalls to Avoid

• Never delay antibiotic initiation if infection suspected - infections are primary cause of maternal death 7
• Do not use ACE inhibitors or ARBs - these are teratogenic and contraindicated throughout pregnancy
• Avoid aggressive diuresis causing hypovolemia, which can compromise placental perfusion 4
• Do not assume proteinuria is physiologic at 16 weeks - this warrants full nephrotic workup 2, 6
• Measure ionized calcium, not total calcium, as hypoalbuminemia falsely lowers total calcium 4

Postpartum Management

Continue close monitoring postpartum, as renal function may worsen after delivery 5, 6:

• Some patients require dialysis postpartum even if avoided during pregnancy 3
• Can liberalize immunosuppression options if not breastfeeding
• Reassess renal function at 2 and 5 months postpartum 6