Reinfeldt Engberg G, Mantel Ä, Fossum M, Nordenskjöld A
Department of Women's and Children's Health and Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden; Department of Pediatric Surgery, Section of Urology, Astrid Lindgren Children's Hospital, Karolinska University Hospital, Stockholm, Sweden.
Clinical Epidemiology Unit, Department of Medicine, Solna (MedS), K2, Karolinska Institutet, Stockholm, Sweden.
J Pediatr Urol. 2016 Oct;12(5):304.e1-304.e7. doi: 10.1016/j.jpurol.2016.05.035. Epub 2016 Jul 15.
Bladder exstrophy is a rare, congenital, complex malformation where the underlying cause is largely unknown. Both environmental and genetic mechanisms are thought to be involved. There are divergent results concerning the prevalence, birth descriptive data, and potential maternal risk factors for bladder exstrophy. Few previous studies have reflected nationwide populations, population registers, or spanned a longer period of time.
To describe and assess bladder exstrophy and the potential maternal risk factors, for a time period of four decades, by conducting a nationwide register study of bladder exstrophy in Sweden.
A matched-design, case-control, linkage-analysis study nested within the entire pool of live births in Sweden between 1973 and 2011 was performed. Cases with bladder exstrophy were identified using nationwide population-based birth and health registers. Inclusion criteria were people born in Sweden with the classification of bladder exstrophy according to the ICD coding system. Cases were matched with five controls per patient, based on birth year and sex. Prevalence was assessed and birth descriptive data were compiled. Potential maternal risk factors were obtained from medical birth registers of cases and assessed using conditional and multivariate logistic regression models to obtain odds ratios as a measure of the relative risk. Classification of the diagnosis in the registers constituted a possible limitation for determining the correct study population, which demanded strict validation and inclusion criteria. All data were collected prospectively, thereby avoiding potential recall bias.
The prevalence was calculated to be approximately 3 per 100,000 live births, with a male-to-female ratio of 1.14:1. In 92.5% of the cases, bladder exstrophy was an isolated malformation without associated major malformations. However, 41% had had surgery for congenital inguinal hernia and 11% of the male subjects had been operated on for cryptorchidism. A significantly higher proportion of cases had a birth weight <1500 g compared with controls, but other characteristics were comparable with controls. High maternal age was the only significant potential associated maternal risk factor.
One hundred and twenty children born with bladder exstrophy in Sweden during the last four decades were identified; this resulted in prevalence in Sweden of 3 per 100,000. The prevalence was stable over time and the sex ratio was equal. Birth characteristics were comparable to controls, and bladder exstrophy generally occurred as an isolated malformation without major associated malformations. Advanced maternal age was the only significant potential maternal risk factor.
膀胱外翻是一种罕见的先天性复杂畸形，其根本病因大多未知。环境和遗传机制均被认为与之相关。关于膀胱外翻的患病率、出生描述数据以及潜在的母亲风险因素，存在不同的研究结果。此前很少有研究反映全国性人群、人口登记情况或涵盖较长时间段。
通过对瑞典膀胱外翻进行全国性登记研究，描述和评估四十年来的膀胱外翻及潜在的母亲风险因素。
在1973年至2011年瑞典所有活产婴儿中开展一项匹配设计、病例对照、连锁分析研究。利用基于全国人口的出生和健康登记册确定膀胱外翻病例。纳入标准为在瑞典出生且根据国际疾病分类编码系统分类为膀胱外翻的人群。根据出生年份和性别，为每位病例匹配五名对照。评估患病率并汇编出生描述数据。从病例的医学出生登记册中获取潜在的母亲风险因素，并使用条件和多变量逻辑回归模型进行评估，以获得比值比作为相对风险的衡量指标。登记册中的诊断分类可能是确定正确研究人群的一个限制因素，这需要严格的验证和纳入标准。所有数据均前瞻性收集，从而避免潜在的回忆偏倚。
计算得出患病率约为每10万活产婴儿中有3例，男女比例为1.14:1。在92.5%的病例中，膀胱外翻是一种孤立畸形，无相关重大畸形。然而，41%的病例因先天性腹股沟疝接受过手术，11%的男性受试者因隐睾症接受过手术。与对照组相比，出生体重<1500克的病例比例显著更高，但其他特征与对照组相当。母亲年龄较大是唯一显著的潜在相关母亲风险因素。
在过去四十年中，瑞典共确定了120例患有膀胱外翻的儿童；这使得瑞典的患病率为每10万中有3例。患病率随时间稳定，性别比例均衡。出生特征与对照组相当，膀胱外翻通常表现为孤立畸形，无重大相关畸形。母亲年龄较大是唯一显著的潜在母亲风险因素。
