This case involves a 35-year-old woman who developed severe swelling and shortness of breath after delivering her baby. Despite initial concerns about a pregnancy-related condition called preeclampsia, further investigation revealed she had a rare kidney disorder called focal segmental glomerulosclerosis (FSGS). The case highlights how kidney diseases can mimic pregnancy complications and why persistent symptoms after delivery require thorough evaluation.
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A Young Mother's Struggle with Swelling and Breathlessness: Understanding a Complex Kidney Diagnosis
Table of Contents
- Background: Why This Case Matters
- Case Presentation: The Patient's Story
- Medical History and Initial Findings
- Differential Diagnosis: Sorting Through Possibilities
- Final Diagnosis and Pathology Findings
- Clinical Implications for Patients
- Limitations and Uncertainties
- Patient Recommendations
- Source Information
Background: Why This Case Matters
This case illustrates the diagnostic challenges when kidney problems develop during or after pregnancy. What initially appeared to be a common pregnancy complication turned out to be a rare kidney condition that required specialized treatment. The case demonstrates why persistent symptoms after delivery warrant thorough investigation, even when they resemble typical postpartum issues.
Pregnancy causes significant changes in a woman's body, particularly in kidney function and fluid balance. Normally, the kidneys work harder during pregnancy, filtering more blood and processing more fluids. However, these changes can sometimes mask or mimic serious underlying conditions that require different treatments than standard pregnancy-related issues.
Case Presentation: The Patient's Story
A 35-year-old woman arrived at Massachusetts General Hospital experiencing severe shortness of breath and noticeable swelling in her legs. Her medical journey began eight weeks earlier when she was admitted to deliver her baby at 39 weeks of pregnancy due to her advanced maternal age and concerns about the baby's size.
During her pregnancy, she had taken low-dose aspirin starting at 13 weeks to reduce her risk of preeclampsia, a serious pregnancy complication. She had no history of high blood pressure before or during pregnancy. Upon admission for delivery, her blood pressure measured 141/81 mm Hg, and doctors noted pitting edema (swelling that leaves an indentation when pressed) in her legs.
Laboratory tests revealed concerning results: her blood albumin level was 2.1 g/dL (normal range: 3.3-5.0 g/dL), and her urine protein-to-creatinine ratio was 4.1 (normal: <0.15). Despite these findings, she had no headache, vision changes, or breathing difficulties at that time. She delivered a healthy baby vaginally after receiving medication to induce labor.
Medical History and Initial Findings
After delivery, the patient's blood pressure improved to 122/88 mm Hg, and she was discharged on the fifth day. At home, her blood pressure readings remained below 140 mm Hg systolic, and she lost 9 kg (approximately 20 pounds) of weight in the first two weeks after delivery.
Six weeks before her current hospitalization, she developed a persistent headache that ranged from 3 to 10 on a pain scale (with 10 being the most severe pain). The pain improved with ibuprofen. Four weeks before admission, she noticed swelling returning to her feet and legs, along with continued headaches.
Over the next week, the swelling worsened, and she gained 6 kg (about 13 pounds) despite normal blood pressure readings. When evaluated at the hospital's antepartum unit, her blood pressure was 121/71 mm Hg with symmetric pitting edema in her legs. Doctors recommended continuing ibuprofen for headaches and referred her to neurology.
One week before her current admission, she visited another hospital's emergency department for increased leg swelling. Tests showed:
- Blood urea nitrogen: 22 mg/dL (normal: 6-20 mg/dL)
- Creatinine: 0.70 mg/dL (normal: 0.50-1.10 mg/dL)
- Albumin: 1.5 g/dL (normal: 3.5-5.2 g/dL)
- Total protein: 4.8 g/dL (normal: 5.8-7.7 g/dL)
- Normal B-type natriuretic peptide (BNP) level
Doctors found no blood clots in her legs and started her on oral furosemide, a diuretic medication, before discharging her.
Over the next six days, her weight continued to increase, leg swelling worsened, and she developed shortness of breath with exertion. She returned to the emergency department with ongoing headaches and a weight gain of 11 kg (approximately 24 pounds) above her lowest post-delivery weight.
Her medical history included obesity (with a pre-pregnancy BMI of 40) and anxiety. Routine prenatal tests conducted nine months earlier showed negative results for HIV, hepatitis B, and hepatitis C, with normal hemoglobin A1c and thyroid levels. She had no known drug allergies except for penicillin which caused hives.
On examination, her vital signs showed:
- Temperature: 35.8°C (96.4°F)
- Blood pressure: 142/85 mm Hg
- Pulse: 62 beats per minute
- Respiratory rate: 16 breaths per minute
- Oxygen saturation: 98% on room air
- BMI: 45.2
Doctors noted pitting edema in her legs and ordered additional tests that revealed:
- Blood albumin: 2.2 g/dL
- Normal BNP level
- Elevated TSH (thyroid-stimulating hormone): 7.87 μIU/mL (normal: 0.40-5.00)
- Low free thyroxine: 0.9 ng/dL (normal: 0.9-1.8)
- Urinalysis: 3+ protein (normal: negative)
- Urine protein-to-creatinine ratio: 5.2
Imaging studies including chest X-ray, CT scan for pulmonary embolism, and leg ultrasound showed no significant abnormalities except for mild bronchial wall thickening.
Differential Diagnosis: Sorting Through Possibilities
The medical team faced a complex diagnostic challenge. The patient showed signs of nephrotic syndrome - a condition characterized by heavy protein in urine (proteinuria), low blood albumin levels (hypoalbuminemia), and swelling (edema). In pregnancy, this can result from either pregnancy-specific conditions or new-onset kidney diseases.
Preeclampsia was initially considered because it's the most common cause of nephrotic-range proteinuria in pregnancy. The patient had risk factors including pre-pregnancy obesity and advanced maternal age. However, several features argued against preeclampsia:
- She had only mildly elevated blood pressure readings
- Her symptoms worsened rather than improved after delivery
- Proteinuria typically resolves within 6 weeks after delivery in preeclampsia, but hers persisted
Doctors explained that preeclampsia involves an imbalance of specific proteins (sFlt-1 and PlGF) released by the placenta. Measurement of these proteins can help distinguish preeclampsia from other conditions, though this testing wasn't performed in this case.
Other possible conditions included:
Minimal Change Disease: A common cause of nephrotic syndrome in children that can rarely occur in adults. However, the patient's gradual symptom development over weeks rather than days made this less likely, as minimal change disease typically appears rapidly.
Membranous Nephropathy: A common primary nephrotic syndrome in adults, usually affecting older white men. The patient's age and gender made this diagnosis unlikely.
Lupus Membranous Nephropathy: A kidney manifestation of systemic lupus erythematosus that can occur in women of reproductive age. However, the patient showed no other signs of lupus, such as joint pain, skin rashes, or positive autoimmune antibodies.
Focal Segmental Glomerulosclerosis (FSGS): One of the most common causes of nephrotic syndrome in adults. This condition involves scarring in the kidney's filtering units and can present with exactly the symptoms this patient experienced. Her age and disease course made this the most likely diagnosis among the primary kidney diseases.
Final Diagnosis and Pathology Findings
The medical team performed a kidney biopsy to confirm the diagnosis. The pathology examination revealed:
The biopsy sample contained 24 glomeruli (the kidney's filtering units), with 4 showing changes consistent with focal segmental glomerulosclerosis (FSGS). One glomerulus showed collapsing features - a more severe form of FSGS characterized by proliferation of epithelial cells surrounding areas of scarring.
Special staining techniques showed duplication of the glomerular basement membrane, suggesting chronic injury to the blood vessels within the kidney. This finding can be associated with various conditions including reduced blood flow, blood clotting disorders, or certain types of kidney inflammation.
Electron microscopy revealed extensive foot process effacement - a characteristic finding in nephrotic syndrome where the specialized cells that prevent protein leakage become damaged and flattened.
Immunofluorescence testing showed no significant antibody deposits, helping to rule out conditions like lupus nephritis or membranous nephropathy.
The final diagnosis was primary focal segmental glomerulosclerosis, specifically the collapsing variant which tends to be more aggressive and less responsive to standard treatments.
Clinical Implications for Patients
This case has several important implications for patients, particularly women of childbearing age:
First, it highlights that not all swelling and proteinuria during or after pregnancy is due to preeclampsia. While preeclampsia is common and serious, other kidney conditions can present with similar symptoms but require completely different treatments.
Second, persistent symptoms after delivery warrant thorough investigation. The fact that this patient's swelling and proteinuria worsened rather than improved after childbirth was a crucial clue that something beyond typical pregnancy-related changes was occurring.
Third, kidney biopsy remains an essential tool for diagnosing complex kidney conditions. Despite advances in blood tests and imaging, sometimes examining actual kidney tissue under a microscope is necessary for accurate diagnosis and treatment planning.
Fourth, FSGS can occur in previously healthy young adults without warning. This condition affects approximately 7 people per million annually and can lead to progressive kidney damage if not properly diagnosed and treated.
Limitations and Uncertainties
This case presentation has several limitations that patients should understand:
The diagnosis relied heavily on the kidney biopsy findings, which represent a single point in time. Kidney diseases can evolve, and sometimes repeat biopsies are needed to guide ongoing treatment.
The case doesn't provide long-term follow-up information about how the patient responded to treatment or how her kidney function progressed over time. FSGS can have variable courses, with some patients responding well to treatment while others progress to kidney failure.
The exact trigger for her FSGS remains unknown. In many cases, the cause of primary FSGS isn't identified, though pregnancy and its associated immune changes might have played a role in triggering the condition.
The case doesn't detail specific treatment recommendations beyond diagnosis. Management of FSGS typically involves medications that suppress the immune system, blood pressure control, and dietary modifications, but responses vary significantly between patients.
Patient Recommendations
Based on this case, patients should consider the following recommendations:
- Monitor symptoms carefully during and after pregnancy. While some swelling is normal, rapid weight gain, severe swelling, or shortness of breath warrant medical attention.
- Follow up persistently if symptoms continue after delivery. Don't assume that postpartum symptoms will automatically resolve with time.
- Ask about specialized testing if kidney issues are suspected. This might include 24-hour urine collection for protein measurement, blood tests for kidney function, and referrals to kidney specialists (nephrologists).
- Understand that kidney biopsy is a safe procedure when performed by experienced physicians. While it involves some risks, the diagnostic information often outweighs these concerns when complex kidney conditions are suspected.
- Seek care at centers with experience in both kidney diseases and high-risk pregnancies if possible, as these conditions require specialized expertise.
For patients diagnosed with FSGS, working closely with a nephrologist is essential. Treatment typically involves a combination of medications, dietary changes, and careful monitoring of kidney function over time.
Source Information
Original Article Title: Case 1-2025: A 35-Year-Old Woman with Shortness of Breath and Edema in the Legs
Authors: Jessica S. Tangren, M.D., Anushya Jeyabalan, M.D., and Veronica E. Klepeis, M.D., Ph.D.
Publication: The New England Journal of Medicine, January 9, 2025
DOI: 10.1056/NEJMcpc2402498
This patient-friendly article is based on peer-reviewed research from Massachusetts General Hospital case records.