Abstract: FR-PO0704
A Rare Case of Primary Membranous Nephropathy in Pregnancy
Session Information
- Glomerular Diseases: Membranous Nephropathy, FSGS, and Podocytopathies
October 23, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics
Authors
- Ramaswami, Akshaya, Yale School of Medicine, New Haven, Connecticut, United States
- Berry, Shivankshi, Yale School of Medicine, New Haven, Connecticut, United States
- Brewster, Ursula C., Yale School of Medicine, New Haven, Connecticut, United States
Introduction
Membranous nephropathy is an immune-mediated glomerular disease that can cause nephrotic syndrome. It is uncommon in young women and even rarer when first diagnosed in pregnancy, where it increases risks of worsening proteinuria, thrombosis, preterm delivery, and fetal growth complications.
Case Description
A 30-year-old G3P0020 woman with two early miscarriages was referred at 28 weeks’ gestation for rapidly worsening proteinuria, rising from 1.5 g/day at 17 weeks to 9 g/day by 27 weeks. She was on progesterone and low-dose aspirin, and blood pressure remained controlled.
Given the severity of proteinuria, a kidney biopsy was performed. Pathology showed membranous nephropathy with weak PLA2R and THSD7A staining, absent intramembranous deposits, and overall suggestive of primary MN except for negative IgG4. Prednisone 60 mg daily with PJP and GI prophylaxis was initiated. Serum PLA2R, drawn after steroid exposure, was negative. Hypoalbuminemia required LMWH prophylaxis and steroid-associated gestational diabetes and hypertension complicated her course. Proteinuria rose to ~15 g/day, prompting induction at 36 weeks. She developed second-stage arrest with chorioamnionitis and underwent cesarean delivery. Postpartum, proteinuria initially remained high, and rituximab was considered after 12 weeks of postpartum; however, spontaneous improvement occurred, and steroids were tapered off.
Discussion
This is a one-of-a-kind case where a biopsy has been performed in the second trimester with extremely close maternal-fetal monitoring, and successful treatment using steroids with good maternal and fetal outcomes. Uchino et al., describe clearer biopsy findings with prompt postpartum remission. In our case, limited diagnostic clarity and unavailable pretreatment PLA2R complicated assessment. There is limited data regarding the incidence of primary membranous nephropathy in pregnant patients. Packham et al., showed that marked proteinuria during the first trimester is a highly significant marker of poor prognosis. Management of pMN in pregnancy is challenging and there are no clear guidelines for the same. It is difficult for individuals with nephrotic syndrome to carry their pregnancy to term, requiring close monitoring and personalized care. Previous case reports and case series show that biopsies have been performed predominantly in the first trimester. Treatment options include rituximab (first trimester), corticosteroids, and tacrolimus.