Challenging Case Discussion: Obstructing Ureteric Stone in Pregnancy with Solitary Kidney (Urology)

Medical Case Details:

A 32-year-old female, currently 22 weeks pregnant (G3P2), presented with severe left flank pain for the past 24 hours, along with nausea, vomiting, and reduced oral intake. The pain was colicky in nature, radiating to the groin, and was not controlled with oral analgesics. She had a history of right donor nephrectomy five years ago, leaving her with a solitary functioning left kidney. Her baseline renal function before pregnancy was normal. On examination, she was afebrile but in visible distress. Blood pressure was 138/86 mmHg, pulse rate was 108/min, and there was marked tenderness over the left flank. There was no uterine tenderness, and fetal heart rate was normal. Investigations showed serum creatinine of 1.3 mg/dL compared to her baseline of 0.8 mg/dL before pregnancy, WBC count of 13.8 x10?/L, CRP of 22 mg/L, and urinalysis showing significant hematuria with mild pyuria. Urine culture was pending. Ultrasound showed moderate to severe left hydronephrosis without clear visualization of a stone and no perinephric collection. Non-contrast MRI KUB suggested a possible 7–8 mm proximal left ureteric calculus with progressive upstream dilatation. Despite IV hydration, opioids, and antiemetics, the pain remained severe and recurrent, and renal function showed early deterioration over 24–48 hours. This raised significant concern for obstructive uropathy in a solitary functioning kidney during pregnancy. The key challenge was deciding the right time for urgent decompression and choosing between JJ stenting, percutaneous nephrostomy, or primary ureteroscopy to prevent further renal damage while ensuring maternal and fetal safety.