Differential Diagnosis for Postpartum Urinary Incontinence

The patient's symptoms of loss of small amounts of urine, low voiding volumes, and high postvoid residual volume after an uncomplicated spontaneous vaginal delivery suggest a urinary retention issue rather than incontinence due to interstitial cystitis. Here's a categorized differential diagnosis:

• Single Most Likely Diagnosis

  • Postpartum urinary retention: This condition is characterized by the inability to empty the bladder completely after childbirth, often presenting with symptoms similar to those described. The high postvoid residual volume is a key indicator of this condition. The use of epidural anesthesia during labor can contribute to this issue by affecting bladder sensation and function.

• Other Likely Diagnoses

  • Overdistension injury to the bladder: Prolonged labor or the use of epidural anesthesia can lead to overdistension of the bladder, causing temporary damage to the detrusor muscle, which can result in urinary retention.
  • Pudendal nerve injury: The pudendal nerve controls the external urethral sphincter. Injury during childbirth can lead to urinary retention due to the inability to properly relax the sphincter during voiding.

• Do Not Miss Diagnoses

  • Urethral trauma or laceration: Although the examination did not show evidence of hematoma, a urethral injury could still be present and cause urinary retention or incontinence. Missing this diagnosis could lead to severe complications, including infection and long-term urinary dysfunction.
  • Bladder neck obstruction: This could be due to swelling or other injuries sustained during delivery, which might not be immediately apparent on examination.

• Rare Diagnoses

  • Interstitial cystitis: As mentioned in the question, this is a condition characterized by bladder pressure, bladder pain, and sometimes pelvic pain. The symptoms provided do not strongly suggest interstitial cystitis, as it typically presents with pain and frequency rather than retention and incontinence of large volumes.
  • Neurogenic bladder due to spinal cord injury from epidural anesthesia: Although extremely rare, complications from epidural anesthesia can include spinal cord injury leading to neurogenic bladder. The presentation would depend on the level and extent of the injury.