DeLancey John O L, Masteling Mariana, Pipitone Fernanda, LaCross Jennifer, Mastrovito Sara, Ashton-Miller James A
Department of Obstetrics and Gynecology, University of Michigan, Ann Arbor, MI.
Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI.
Am J Obstet Gynecol. 2024 Mar;230(3):279-294.e2. doi: 10.1016/j.ajog.2023.11.1253. Epub 2024 Jan 2.
Pelvic floor disorders after childbirth have distressing lifelong consequences for women, requiring more than 300,000 women to have surgery annually. This represents approximately 10% of the 3 million women who give birth vaginally each year. Vaginal birth is the largest modifiable risk factor for prolapse, the pelvic floor disorder most strongly associated with birth, and is an important contributor to stress incontinence. These disorders require 10 times as many operations as anal sphincter injuries. Imaging shows that injuries of the levator ani muscle, perineal body, and membrane occur in up to 19% of primiparous women. During birth, the levator muscle and birth canal tissues must stretch to more than 3 times their original length; it is this overstretching that is responsible for the muscle tear visible on imaging rather than compression or neuropathy. The injury is present in 55% of women with prolapse later in life, with an odds ratio of 7.3, compared with women with normal support. In addition, levator damage can affect other aspects of hiatal closure, such as the perineal body and membrane. These injuries are associated with an enlarged urogenital hiatus, now known as antedate prolapse, and with prolapse surgery failure. Risk factors for levator injury are multifactorial and include forceps delivery, occiput posterior birth, older maternal age, long second stage of labor, and birthweight of >4000 g. Delivery with a vacuum device is associated with reduced levator damage. Other steps that might logically reduce injuries include manual rotation from occiput posterior to occiput anterior, slow gradual delivery, perineal massage or compresses, and early induction of labor, but these require study to document protection. In addition, teaching women to avoid pushing against a contracted levator muscle would likely decrease injury risk by decreasing tension on the vulnerable muscle origin. Providing care for women who have experienced difficult deliveries can be enhanced with early recognition, physical therapy, and attention to recovery. It is only right that women be made aware of these risks during pregnancy. Educating women on the long-term pelvic floor sequelae of childbirth should be performed antenatally so that they can be empowered to make informed decisions about management decisions during labor.
产后盆底功能障碍会给女性带来令人痛苦的终身影响,每年有超过30万名女性需要接受手术治疗。这约占每年300万阴道分娩女性的10%。阴道分娩是子宫脱垂(与分娩关联最紧密的盆底功能障碍)的最大可改变风险因素,也是压力性尿失禁的一个重要促成因素。这些疾病所需的手术数量是肛门括约肌损伤的10倍。影像学检查显示,初产妇中高达19%的人存在肛提肌、会阴体和盆底筋膜损伤。分娩时,肛提肌和产道组织必须伸展至其原始长度的3倍以上;正是这种过度伸展导致了影像学上可见的肌肉撕裂,而非压迫或神经病变。在日后出现子宫脱垂的女性中,55%存在这种损伤,与盆底支持正常的女性相比,其优势比为7.3。此外,肛提肌损伤会影响裂孔闭合的其他方面,如会阴体和盆底筋膜。这些损伤与泌尿生殖裂孔增大(现称为早期脱垂)以及脱垂手术失败有关。肛提肌损伤的风险因素是多方面的,包括产钳助产、枕后位分娩、产妇年龄较大、第二产程延长以及出生体重>4000克。使用真空吸引器分娩与降低肛提肌损伤有关。其他可能合理减少损伤的措施包括从枕后位手动旋转至枕前位、缓慢渐进分娩、会阴按摩或按压以及早期引产,但这些措施需要研究来证实其保护作用。此外,教导女性避免在肛提肌收缩时用力,可能会通过减少脆弱的肌肉起点处的张力来降低损伤风险。通过早期识别、物理治疗和关注恢复情况,可以加强对经历难产女性的护理。在孕期让女性了解这些风险是正确的。应在产前对女性进行有关分娩对盆底长期影响的教育,以便她们能够在分娩期间就管理决策做出明智的决定。