Covert postpartum urinary retention: causes and consequences (PAREZ study)

INTRODUCTION AND HYPOTHESIS: Increased post-voiding residual volume (PVRV), known as covert postpartum urinary retention (PUR), is an asymptomatic condition with unknown long-term adverse effects. The objectives were to determine the frequency of this phenomenon 3 days after delivery and to examine the associated risk factors and consequences of the increased residuum on women´s health 6 weeks postpartum. METHODS: We carried out a prospective observational study including a total of 926 primiparous women, giving birth to singletons. All participants underwent ultrasound determination of PVRV on day 3 postpartum. Then, risk factors were determined using logistic regression analysis. After 6 weeks, participants were invited to return for PVRV determination and to complete urogynecological and general health questionnaires. Using these data, the consequences of increased PVRV were determined. RESULTS: A total of n=90 women were diagnosed with abnormal PVRV. Mean age in the studied population was 30.4 years, BMI prior to delivery 27.8, weight of the newborn 3,420 g, and percentage of cesarean sections 15.9%. Gestational week (p=0.043), vaginal tear (p=0.032), and induction of labor (p=0.003) were risk factors for covert PUR. Puerperal incidence of urinary tract infection was 1.1% (6 out of 526) and of urinary incontinence 29.2% (155 out of 530), with no differences between the groups. In the second examination, covert PUR was no longer present, and the values of residual urine decreased for all patients in the case group. No statistically significant differences were observed in questionnaire scores in general health and wellbeing perceptions between the groups. CONCLUSIONS: We have found a few significant obstetrical–pediatric risk factors for abnormal PVRVs. Data from the follow-up suggest that covert PUR has no impact on morbidity and quality of life 6 weeks postpartum. Therefore, abnormal PVRV is a self-limited phenomenon with a tendency toward self-correction. Our findings support those of previous studies that advocate against screening for asymptomatic retention in the postpartum period, despite some similar previous recommendations.