Does type of anesthesia during procedural management of suspected renal colic during pregnancy have an impact on preterm birth?

INTRODUCTION: Anesthesia choice during the procedural management of suspected renal colic during pregnancy may vary based on available resources and patient or provider preferences, as there are no specific recommendations. Our objective was to evaluate whether preterm birth (<37 weeks) was associated with anesthesia type, anesthesia timing by trimester, or procedure type. METHODS: We retrospectively identified pregnant patients who required procedural management with ureteral stent, percutaneous nephrostomy (PCN), or ureteroscopy (URS) for suspected renal colic based on laboratory and imaging findings from 2009–2021 at our center. Analyzed data included anesthesia type (local analgesia only, monitored anesthesia care [MAC], spinal anesthesia, or general anesthesia), trimester of procedure, procedure type, and obstetric outcomes, including preterm birth. RESULTS: The study cohort included 96 patients who underwent 231 total procedures, including primary URS, PCN, and stent, as well as PCN and stent change. The median gestational age was 38.7 weeks (37.1–39.5), and preterm birth rate was 15.8%. The most common anesthetic used across all procedures and trimesters was MAC. PCN was associated with the use of less invasive analgesia or anesthesia, whereas endoscopic procedures were more commonly performed with spinal or general anesthesia. Using multivariable logistic regression, procedure type was associated with preterm birth, but not anesthesia type or timing by trimester. CONCLUSIONS: Anesthesia type and timing were not associated with preterm birth, and selection may be influenced by resources, clinical scenario, or patient and provider preferences.