Nephrotic Syndrome in the Third Trimester of Pregnancy

Introduction: Nephrotic-range proteinuria during pregnancy is most commonly attributed to preeclampsia, particularly when it occurs after 20 weeks of gestation and is associated with hypertension, thrombocytopenia, or liver dysfunction. However, significant proteinuria that persists or presents atypically should prompt consideration of underlying glomerular pathology. While nephrotic syndrome is relatively rare in pregnancy (0.012–0.025%), it occurs in 10–25% of adults overall. This case highlights the importance of maintaining a broad differential and the utility of renal biopsy in identifying treatable glomerular diseases during pregnancy. Case Description: A woman in her late 20s, gravida 5 para 3, at 37 weeks’ gestation with no past medical history, presented with progressive bilateral lower extremity edema and shortness of breath over 4 weeks. Blood pressure readings ranged from 130–140 mmHg systolic, and lab findings were significant for hypoalbuminemia (0.7 g/dL) and proteinuria of ~14 g/day on 24-hr urine collection. She had normal renal function and urinalysis with 3+ protein one month prior. She had an uncomplicated delivery. Serologies such as ana with reflex, complements, HIV, and hepatitis were unremarkable. A renal biopsy was performed and revealed diffuse podocyte foot process effacement on electron microscopy, consistent with minimal change disease (MCD). She was started on corticosteroids along with Pneumocystis jirovecii pneumonia (PCP) prophylaxis with Bactrim. She achieved complete remission of proteinuria, though she experienced a relapse within a month after discontinuing steroids, requiring a repeat course. She currently remains normotensive, edema-free, with normal kidney function. Discussion: MCD in adults when presented, secondary causes need to be ruled out. In our patient she had no personal or family history for malignancy and she was not due for mammogram or colonoscopy based on age related screening. She was not on any meds such as NSAIDs, lithium or antibiotics that can cause MCD. In pregnant patients with persistent or severe nephrotic-range proteinuria, especially when atypical features are present—such as normal liver enzymes, platelets, and only mild hypertension—clinicians should expand the differential diagnosis to include glomerular diseases. Renal biopsy remains essential in distinguishing these conditions from pre-eclampsia and ensures that targeted, disease-specific therapy can be initiated.