肩难产(SD)定义为头颅表现的阴道分娩,需要在头部分娩且轻柔牵引失败后进行额外的产科操作来分娩胎儿。它使0.5-1%的阴道分娩复杂化。臂丛神经产伤的风险(证据水平[LE]3),锁骨和肱骨骨折(LE3),围产期窒息(LE2),缺氧缺血性脑病(LE3)和围产期死亡率(LE2)随SD增加而增加。其主要危险因素是既往SD和巨大儿,但两者的预测能力都很差;50-70%的SD病例发生在他们缺席的情况下,和大多数交付,当他们存在不会导致SD。没有研究证明纠正这些危险因素(妊娠糖尿病除外)会降低SD的风险。建议在怀孕前和怀孕期间进行体育锻炼,以减少SD(C级)的一些危险因素的发生。在肥胖女性中,身体活动应与饮食措施相结合,以减少怀孕期间胎儿巨大儿和体重增加(A级)。妊娠糖尿病妇女需要糖尿病护理(糖尿病饮食,血糖监测,胰岛素,如果需要)(A级),因为它降低了巨大儿和SD(LE1)的风险。仅提出了两种避免SD及其并发症的措施。首先,如果子宫颈在39周或以上的胎龄是有利的,则在即将发生巨大儿的情况下推荐引产(专业共识)。第二,在三种情况下,建议在分娩前进行剖宫产,在一种情况下:(i)估计胎儿体重(EFW)>4500g,如果与产妇糖尿病(C级)有关,(ii)无糖尿病(C级)的女性EFW>5000g,(iii)与严重新生儿或产妇并发症相关的SD病史(专业共识),最后在分娩过程中,(iv)如果胎儿巨大儿和第二阶段进展失败,胎头站+2以上(C级)。在SD的情况下,建议避免以下行为:胎头过度牵引(C级),底压(C级),和胎儿头部的反向旋转(专业共识)。麦克罗伯茨的演习,有或没有耻骨上压力,首先推荐(C级)。如果失败并且后肩接合,伍德的动作应优先进行;如果后肩没有接合,最好是下一步尝试交付后臂(专业共识)。如果McRoberts机动失败,似乎有必要知道至少要执行两次机动(专业共识)。儿科医生应立即被告知SD。最初的临床检查应该检查并发症,如臂丛神经损伤或锁骨骨折(专业共识)。如果没有观察到并发症,新生儿监护不需要修改(专业共识)。在分娩室中对所有护理提供者实施模拟实践培训与新生儿(LE3)而不是产妇(LE3)损伤的显着减少有关。SD仍然是不可预测的产科急诊。如果需要,所有医生和助产士都应该知道并进行产科操作,迅速但平静。
Shoulder dystocia (SD) is defined as a vaginal delivery in cephalic presentation that requires additional obstetric maneuvers to deliver the fetus after the head has delivered and gentle traction has failed. It complicates 0.5-1% of vaginal deliveries. Risks of brachial plexus birth injury (level of evidence [LE]3), clavicle and humeral fracture (LE3), perinatal asphyxia (LE2), hypoxic-ischemic encephalopathy (LE3) and perinatal mortality (LE2) increase with SD. Its main risk factors are previous SD and macrosomia, but both are poorly predictive; 50-70% of SD cases occur in their absence, and most deliveries when they are present do not result in SD. No study has proven that the correction of these risk factors (except gestational diabetes) would reduce the risk of SD. Physical activity is recommended before and during pregnancy to reduce the occurrence of some risk factors for SD (Grade C). In obese women, physical activity should be coupled with dietary measures to reduce fetal macrosomia and weight gain during pregnancy (Grade A). Women with gestational diabetes require diabetes care (diabetic diet, glucose monitoring, insulin if needed) (Grade A) because it reduces the risk of macrosomia and SD (LE1). Only two measures are proposed for avoiding SD and its complications. First, induction of labor is recommended in cases of impending macrosomia if the cervix is favorable at a gestational age of 39 weeks or more (professional
consensus). Second, cesarean delivery is recommended before labor in three situations and during labor in one: (i) estimated fetal weight (EFW) >4500g if associated with maternal diabetes (Grade C), (ii) EFW >5000g in women without diabetes (Grade C), (iii) history of SD associated with severe neonatal or maternal complications (professional
consensus), and finally during labor, (iv) in case of fetal macrosomia and failure to progress in the second stage, when the fetal head station is above +2 (Grade C). In cases of SD, it is recommended to avoid the following actions: excessive traction on the fetal head (Grade C), fundal pressure (Grade C), and inverse rotation of the fetal head (professional consensus). The McRoberts maneuver, with or without suprapubic pressure, is recommended first (Grade C). If it fails and the posterior shoulder is engaged, Wood\'s maneuver should be performed preferentially; if the posterior shoulder is not engaged, it is preferable to attempt to deliver the posterior arm next (professional
consensus). It appears necessary to know at least two maneuvers to perform should the McRoberts maneuver fail (professional
consensus). A pediatrician should be immediately informed of SD. The initial clinical examination should check for complications, such as brachial plexus injury or clavicle fracture (professional consensus). If no complications are observed, neonatal monitoring need not be modified (professional
consensus). The implementation of practical training with simulation for all care providers in the delivery room is associated with a significant reduction in neonatal (LE3) but not maternal (LE3) injury. SD remains an unpredictable obstetric emergency. All physicians and midwives should know and perform obstetric maneuvers if needed, quickly but calmly.