Prospective comparison of obstetric anal sphincter injury incidence between an Asian and Western hospital.

INTRODUCTION AND HYPOTHESIS: Obstetric anal sphincter injury (OASIS) rates are reported to be higher in Asian women living in Western countries than in those living in Asia, but the reasons for the differences remain unclear. The objectives of this study were for a single examiner to prospectively compare OASIS rates in primiparous Asian women in an Asian and Western birth unit and determine potential birth factors that may influence the possible difference in OASIS incidence. METHODS: This was a prospective observational study based in Hong Kong, China, and Sydney, Australia, involving primiparous women > 36 weeks gestation of Asian descent undergoing vaginal delivery. A single examiner recorded basic patient demographics, observed all the deliveries at both sites, noting birthing techniques, and then examined the women, including a rectal examination, to determine OASIS incidence. RESULTS: Seventy births in Hong Kong and 66 in Sydney were studied. The incidence of OASIS was 34% in Sydney and 10% in Hong Kong (p = 0.001). Birthweight, epidural rate, body mass index, and instrumental delivery were higher in Sydney. Episiotomy rates were higher in Hong Kong (59.2% vs. 82.9%; p = 0.007). When comparing OASIS with no-OASIS, perineal length (OR = 0.36, 95% CI 0.17 to 0.76, p = 0.004) and birthweight (OR = 1.14, 95% CI 1.00 to 1.30, p = 0.039) were independent risk factors for OASIS. CONCLUSIONS: The incidence of OASIS in Asian women is significantly higher in a Western than in an Asian setting. In Asian women, perineal length and birthweight can affect the risk of OASIS at the time of vaginal delivery.

The urinary microbiome in patients with refractory urge incontinence and recurrent urinary tract infection.

INTRODUCTION AND HYPOTHESIS: Urinary urge incontinence is a chronic, debilitating condition that is difficult to treat. Patients refractory to standard antimuscarinic therapy often experience recurrent urinary tract infections (rUTIs). The microbiota of these refractory patients with rUTI remains unexplored. METHODS: A midstream urine (MSU) sample was collected from patients with refractory urge incontinence and coexistent rUTI during acute symptomatic episodes. Culture-based diagnosis was performed using routine microbiological methods. Culture-independent profiling was performed using bacterial 16S RNA profiling. E. coli strain typing was performed by amplicon pyrosequencing of the fimH gene. RESULTS: Over 2 years, 39 patients with refractory urge incontinence and coexistent rUTI were studied, yielding 9 severely affected cases. These 9 patients were carefully monitored for a further 2 years, resulting in the collection of 102 MSU samples, 70 of which were diagnosed as UTI (median of 8 UTIs/woman). Culture-independent analysis of 38 of these samples revealed the existence of a diverse urinary microbiota. Strain typing of E. coli identified instances of rUTI caused by the same persisting strain and by new infecting strains. CONCLUSIONS: Patients with refractory urge incontinence and coexistent rUTI possess a diverse urinary microbiota, suggesting that persistent bladder colonisation might augment the pathology of their chronic condition.