Introduction: Cystinuria is a rare disease which limits the understanding of its impact on pregnancy. We sought to characterize stone disease and management of patients with cystinuria during pregnancy at a single institution. Methods: We completed a retrospective chart review of cystinuria patients at a single institution from 2000-2022. Patients were identified by ICD-10 codes (E72.01) and then included for childbearing potential. Charts were reviewed for urologic history as well as baseline medical and surgical treatment history. We evaluated imaging studies, stone episodes, stone surgeries and complications during pregnancy. This was then compared to the reported historic incidence of renal colic, stone diagnosis and surgical intervention during pregnancy. Results: 44 female patients with cystinuria were identified and 40 were included based on child bearing potential. Patient age ranged from 16-68 years. Nine patients had a total of 27 pregnancies and 20 successful live births. Patients were treated with Thiola (3), urinary alkalinization (4) or fluid alone (5) and all medications were discontinued during pregnancy. Patients had an average of 6 stone surgeries prior to pregnancy. Comorbidities included chronic pain (2), chronic kidney disease (1) and multiple sclerosis (1). Renal colic occurred in 27% of pregnancies requiring an average of 1 renal ultrasound in addition to routine prenatal assessment. Of these, only one patient had confirmed stone events in 2 out of her 4 pregnancies (8.3% of symptomatic patients) which required a total of six surgeries (stent placement, ureteroscopy). The remaining 8 patients did not have any confirmed stone events. Comparatively, the reported incidence of renal colic in all pregnancies is 0.12% with 71% of these patients having confirmed stone events and 28% of them undergoing surgical intervention. Comparing pre- and post-partum imaging, 4 patients had radiographic evidence of stone growth during pregnancy. Pregnancies were complicated by 4 (15%) spontaneous abortions in the first trimester and one patient developed a ureteral stricture after ureteroscopy during pregnancy that required delayed reconstruction. Conclusions: Patients with cystinuria are at an increased risk of renal colic episodes during pregnancy but these symptomatic patients do not have a higher rate of stone diagnosis or surgical intervention. Cystinuria patients do not seem to increased complications during pregnancy. However, given a high rate of new stone formation, close follow up of these patients in the post-partum period is necessary. SOURCE OF Funding: None.
