Introduction and hypothesis: Postpartum urinary retention (PUR) is a common consequence of bladder dysfunction after vaginal delivery. Patients with covert PUR are able to void spontaneously but have a postvoid residual bladder volume (PVRV) of ≥150 mL. Incomplete bladder emptying may predispose to bladder dysfunction at a later stage of life. The aim of this cross-sectional study was to identify independent delivery-related risk factors for covert PUR after vaginal delivery in order to identify women with an increased risk of covert PUR.
Methods: The PVRV of women who delivered vaginally was measured after the first spontaneous micturition with a portable bladder-scanning device. A PVRVof 150 mL or more was defined as covert PUR. Independent risk factors for covert PUR were identified in multivariate regression analysis.
Results: Of 745 included women, 347 (47 %) were diagnosed with covert PUR (PVRV ≥150 mL), of whom 197 (26 %) had a PVRV ≥250 mL (75th percentile) and 50 (7 %) a PVRV ≥500 mL (95th percentile). In multivariate regression analysis, episiotomy (OR 1.7, 95 % CI 1.02 – 2.71), epidural analgesia (OR 2.08, 95 % CI 1.36 – 3.19) and birth weight (OR 1.03, 95 % CI 1.01 – 1.06) were independent risk factors for covert PUR. Opioid analgesia during labour (OR 3.19, 95 % CI 1.46 – 6.98), epidural analgesia (OR 3.54, 95 % CI 1.64 – 7.64) and episiotomy (OR 3.72, 95 % CI 1.71 – 8.08) were risk factors for PVRV ≥500 mL.
Conclusions: Episiotomy, epidural analgesia and birth weight are risk factors for covert PUR. We suggest that the current cut-off values for covert PUR should be reevaluated when data on the clinical consequences of abnormal PVRV become available.
In the puerperium, postpartum urinary retention (PUR) is a common finding which gives an increased risk of persistent urinary retention [1–6]. Reported prevalences for overt (symptomatic) PUR range from 0.3 % to 4.7 %, i.e. the inability to void spontaneous within 6 h of vaginal delivery or removal of a catheter after a caesarean section [1, 7]. For covert (asymptomatic) PUR, defined as a postvoid residual volume (PVRV) of at least 150 mL after spontaneous micturition, prevalences of even up to 45 % have been reported . Since Yip et al. proposed a distinction between overt and covert PUR in 1997 , many authors have adopted these definitions, which has led to a more consistent comparison between studies that deal with this common problem. The distinction between overt and covert PUR has clinical consequences. Women who are unable to micturate spontaneously within 6 h of delivery are categorized as having overt (symptomatic) urinary retention. Covert (asymptomatic) urinary retention is defined as the presence of a PVRV of more than 150 mL, detected by ultrasonography or by catheterization after spontaneous micturition.Numerous studies have shown spontaneous recovery after several days to a normal PVRV in women with covert PUR [1, 5, 8, 9]. A recent systematic review on the adverse effects of PUR has shown that there is insufficient evidence to state that covert PUR is harmless . However, it is known that overdistension of the bladder, even a single episode of over-distension, can lead to long-lasting voiding difficulties, recurrent urinary tract infections and, rarely, impaired renal function [11–13]. Sometimes long-term catheterization may be indicated when retention persists or irreversible damage to the urogenital tract has occurred. Possibly, screening for covert PUR might be indicated to limit these risks. This cross-sectional study was performed to identify risk factors for covert PUR.