Department of Obstetrics and Gynaecology, Our Lady of Lourdes Hospital, Drogheda, Co. Louth, Ireland.
Ir J Med Sci. 2021 May;190(2):693-699. doi: 10.1007/s11845-020-02358-5. Epub 2020 Sep 12.
Obstetric anal sphincter injury (OASI) is the most common cause of anal incontinence. Identifying risk factors may facilitate change in labour and delivery practice, potentially reducing the risk. The objective of this study is to identify maternal, foetal and intrapartum risk factors for OASI in a regional hospital.
We conducted a retrospective analysis of vaginal deliveries over a 10-year period (2008-2017). Anal sphincter injury was diagnosed by an experienced clinician and classified according to RCOG recommendations. A multiple logistic regression model was created using the presence of OASI as the dependent variable. Coefficients were adjusted for relevant maternal, foetal and intrapartum risk factors.
During the study period, there were 23,887 vaginal deliveries. Of these births, 18,550 were spontaneous (77.66%), 3746 vacuum-assisted (15.68%), 1196 forceps (5.01%) and 395 sequential instrumental deliveries (1.65%). The overall rate of OASI was 1.76%, with an upward trend seen in nulliparous mothers. Significant factors that increased the risk of OASI were nulliparity, Asian ethnicity, delivery by forceps or sequential instruments, and shoulder dystocia. Vacuum delivery did not significantly increase risk.
Maternal age ≥ 35 years confers a protective effect after adjusting for parity, birth weight and mode of delivery. Given the context of an ageing reproductive population, additional research is required to investigate the impact of maternal age on anal sphincter injury.
产科肛门括约肌损伤（OASI）是肛门失禁最常见的原因。确定危险因素可能有助于改变分娩和分娩实践，从而降低风险。本研究的目的是在一家地区医院确定产科肛门括约肌损伤的产妇、胎儿和分娩期危险因素。
我们对 10 年期间（2008-2017 年）的阴道分娩进行了回顾性分析。肛门括约肌损伤由经验丰富的临床医生诊断，并根据 RCOG 建议进行分类。使用 OASI 的存在作为因变量创建了多变量逻辑回归模型。使用相关的产妇、胎儿和分娩期危险因素对系数进行调整。
在研究期间，有 23887 例阴道分娩。在这些分娩中，18550 例为自发性（77.66%），3746 例为真空辅助（15.68%），1196 例为产钳（5.01%），395 例为连续器械分娩（1.65%）。OASI 的总体发生率为 1.76%，初产妇的发生率呈上升趋势。增加 OASI 风险的显著因素是初产妇、亚洲人种、产钳或连续器械分娩以及肩难产。真空分娩并未显著增加风险。
调整产次、出生体重和分娩方式后，年龄≥35 岁的产妇具有保护作用。鉴于生殖人口老龄化的背景，需要进一步研究年龄对肛门括约肌损伤的影响。
