Management of Postpartum Bladder Atony After Vaginal Delivery
Bladder atony after vaginal delivery should be managed with intermittent catheterization rather than prolonged indwelling catheterization, with bethanechol as a pharmacologic option for neurogenic bladder atony with retention. 1
Initial Recognition and Assessment
Postpartum urinary retention (bladder atony) occurs in approximately 14.6% of women after vaginal delivery, with 4.9% experiencing overt retention (inability to void) and 9.7% experiencing covert retention (incomplete bladder emptying). 2
Measure post-void residual bladder volume at 4-6 hours postpartum to identify retention early, as unrecognized bladder overdistension can lead to detrusor muscle damage, parasympathetic nerve fiber injury, and long-term voiding dysfunction. 3, 4
A post-void residual volume >150 mL indicates significant retention requiring intervention. 4
Risk factors include nulliparity (1.53-fold increased risk), cesarean section (2.21-fold increased risk), and 3rd/4th degree perineal trauma (2.01-fold increased risk); however, all postpartum women warrant screening rather than risk-factor-based approaches alone. 4
Primary Management Strategy
Implement clean intermittent catheterization (CIC) rather than prolonged indwelling catheterization for persistent bladder atony beyond initial management. 5
Intermittent catheterization offers superior outcomes including greater patient acceptance, reduced urinary tract infection rates compared to prolonged indwelling catheters, and prevention of repetitive overdistension injury. 5, 3
Patients can learn self-intermittent catheterization with minimal instruction and should be taught this technique for home management. 5
Pharmacologic Intervention
Bethanechol chloride is FDA-approved specifically for postpartum nonobstructive (functional) urinary retention and neurogenic bladder atony with retention. 1
Bethanechol works as a cholinergic agonist to stimulate bladder detrusor muscle contraction. 1
Timeline and Prognosis
Most cases of covert retention resolve spontaneously within 4 days postpartum without specific treatment beyond monitoring. 2
For persistent cases requiring intervention, resolution typically occurs within 24-37 days postpartum with appropriate management using intermittent catheterization. 5
If an indwelling catheter is initially placed, remove it after one week maximum and transition to intermittent catheterization if retention persists. 6
Critical Pitfalls to Avoid
Do not rely on BladderScan® ultrasound devices for measuring post-void residual one week postpartum, as these devices significantly overestimate residual volumes (mean difference of 312 mL) with poor specificity (17.6%) in this population. 6
Clean intermittent catheterization remains the gold standard for measuring post-void residual volumes when accuracy is needed. 6
Never allow prolonged bladder overdistension to continue untreated, as this can lead to permanent detrusor atony, long-term voiding dysfunction, and in rare cases, bladder rupture—a potentially life-threatening but entirely preventable complication. 3
Distinguish bladder atony from uterine atony, as the provided evidence about uterine massage and uterotonics applies to uterine atony (postpartum hemorrhage), not bladder dysfunction. 7