Covert postpartum urinary retention, is there a place for routine bladder ultrasound in postpartum care ?

Objective: Postpartum urinary retention(PUR) is defined as inability to void after six hours from delivery or having abnormal post-void residual volume after delivery (PVRV). Overt PUR is easily detectable condition but covert PUR usually remains undiagnosed. We aim to investigate the incidence of covert PUR and identify the risk factors. Material and Methods: A retrospective analysis of the postpartum women was undertaken between January-July 2016. PVRV of the patients either delivered vaginally or cesarean section were assessed with ultrasound after first micturition. All the ultrasound scans were made by experienced gynecologist. PVRV of more than 150 mL was defined as covert PUR. Maternal age, parity, BMI, type of delivery, episiotomy, first urination time, fetal head circumference, labor augmentation and fetal birth weight were investigated as possible risk factors for covert PUR. The characteristics of the patients with or without covert PUR were compared. Results: Of the 450 women included, 67 (17.49%) were diagnosed as covert PUR. Birth weight (p= 0.001), head circumference (p=0.043), vaginal delivery (p=0.001) and need for episiotomy (p=0.003) were statistically different between patients with PVRV under 150 mL and above 150 mL. Fetal head circumference appeared as the only independent risk factor for covert PUR (95% CI for OR=1.11-1.127, p=0.04). Conclusions: Although covert PUR is a common problem after delivery, risk factors and treatment have not been established. Until risk factors are identified clearly with larger studies, postpartum routine PVRV evaluation may be beneficial for preventing long-term voiding dysfunction problems.