Department of Obstetrics and Gynaecology, Epsom and St. Helier University Hospitals NHS Trust, Epsom.
Institute of Medical and Biomedical Education, St. George's University of London, London.
Neurourol Urodyn. 2018 Nov;37(8):2717-2723. doi: 10.1002/nau.23727. Epub 2018 Sep 6.
Increasing numbers of twin pregnancies necessitate investigation of the risk factors associated with obstetric anal sphincter injuries (OASIS). The aims of this study were to establish the incidence of OASIS, and compare women delivering twins to those delivering singletons in risk of OASIS plus maternal, neonatal, and obstetric outcomes.
A retrospective cohort study was undertaken and included women delivering in a tertiary London maternity unit between 1999 and 2015; 51 957 eligible women with singleton and 261 with twin pregnancies were identified. Women delivering twins were compared to those delivering singletons in the occurrence of maternal, neonatal, and obstetric outcomes using unadjusted relative risks. A secondary analysis was performed, and conditional logistic regression used to derive an adjusted relative risk of OASIS. Women delivering singletons were matched to those delivering twins for age, parity, ethnicity, gestation, and mode of delivery in a ratio of 2:1.
Compared to the singleton group, mothers delivering twins had significantly more instrumental deliveries (RR [95%CI] 1.92 [1.67-2.27]; P < 0.0001), smaller fetuses (2754.1 vs 3383.8 g; P < 0.001), and were older (32.9 vs 31.0 years; P < 0.0001). The twin group was not significantly different to the singleton group in risk of OASIS (RR 0.61 [0.27-1.33], P = 0.205). The conditional logistic regression demonstrated similar results for the risk of OASIS (adjusted RR = 0.58 [0.22-1.47]; P = 0.253).
Women delivering twins vaginally were not at a significantly higher risk of sustaining OASIS compared to those delivering singletons.
随着双胞胎妊娠数量的增加，有必要研究与产科肛门括约肌损伤（OASIS）相关的危险因素。本研究旨在确定 OASIS 的发生率，并比较分娩双胞胎和单胎的产妇、新生儿和产科结局的风险。
进行了一项回顾性队列研究，纳入了 1999 年至 2015 年期间在伦敦一家三级妇产医院分娩的女性；确定了 51957 名符合条件的单胎妊娠妇女和 261 名双胎妊娠妇女。采用未调整的相对风险比较分娩双胞胎的妇女和分娩单胎的妇女发生产妇、新生儿和产科结局的情况。进行了二次分析，并使用条件逻辑回归得出 OASIS 的调整相对风险。以 2:1 的比例按年龄、产次、种族、孕周和分娩方式将分娩单胎的妇女与分娩双胞胎的妇女进行匹配。
与单胎组相比，分娩双胞胎的母亲剖宫产率显著更高（RR [95%CI] 1.92 [1.67-2.27]；P<0.0001），胎儿较小（2754.1 与 3383.8g；P<0.001），年龄更大（32.9 与 31.0 岁；P<0.0001）。双胞胎组与单胎组的 OASIS 风险无显著差异（RR 0.61 [0.27-1.33]，P=0.205）。条件逻辑回归也显示 OASIS 风险相似（调整 RR=0.58 [0.22-1.47]；P=0.253）。
与分娩单胎的产妇相比，阴道分娩的双胞胎产妇发生 OASIS 的风险没有显著增加。
