Rethinking Time-to-Exchange: Outcomes of Nephrostomy Tube Placement in Pregnancy

This study evaluated outcomes for percutaneous nephrostomy tube placement in pregnant patients, including potential complications that required early, unplanned tube exchange. A retrospective review was conducted for 51 pregnant patients and a nonpregnant cohort matched 1:1 who received percutaneous nephrostomy tube placement between 2012 and 2020. Factors potentially contributing to unplanned tube exchanges were analyzed, including gestational age, prevalence and severity of hydronephrosis, presence of renal calculi, and serum calcium level. The mean tube exchange interval was significantly shorter in the pregnant group (3.4 weeks ± 1.8 [standard deviation] vs 5.7 weeks ± 0.7, P < .0001), and pregnant subjects were significantly more likely to require reintervention before the 6-week scheduled exchange (80.4% vs 21.6%, P < .0001). The serum calcium level was lower in pregnant subjects (8.4 mg/dL ± 0.4 vs 8.9 mg/dL ± 0.7, P = .002). A shorter interval schedule (every 3 weeks) of routine percutaneous nephrostomy tube exchange in pregnant patients may be necessary to avoid complications.