Obstet Gynecol. 2019 Jul;134(1):1. doi: 10.1097/AOG.0000000000003334.
Group B streptococcus (GBS) is the leading cause of newborn infection. The primary risk factor for neonatal GBS early-onset disease (EOD) is maternal colonization of the genitourinary and gastrointestinal tracts. Approximately 50% of women who are colonized with GBS will transmit the bacteria to their newborns. Vertical transmission usually occurs during labor or after rupture of membranes. In the absence of intrapartum antibiotic prophylaxis, 1-2% of those newborns will develop GBS EOD. Other risk factors include gestational age of less than 37 weeks, very low birth weight, prolonged rupture of membranes, intraamniotic infection, young maternal age, and maternal black race. The key obstetric measures necessary for effective prevention of GBS EOD continue to include universal prenatal screening by vaginal-rectal culture, correct specimen collection and processing, appropriate implementation of intrapartum antibiotic prophylaxis, and coordination with pediatric care providers. The American College of Obstetricians and Gynecologists now recommends performing universal GBS screening between 36 0/7 and 37 6/7 weeks of gestation. All women whose vaginal-rectal cultures at 36 0/7-37 6/7 weeks of gestation are positive for GBS should receive appropriate intrapartum antibiotic prophylaxis unless a prelabor cesarean birth is performed in the setting of intact membranes. Although a shorter duration of recommended intrapartum antibiotics is less effective than 4 or more hours of prophylaxis, 2 hours of antibiotic exposure has been shown to reduce GBS vaginal colony counts and decrease the frequency of a clinical neonatal sepsis diagnosis. Obstetric interventions, when necessary, should not be delayed solely to provide 4 hours of antibiotic administration before birth. This Committee Opinion, including , , and , updates and replaces the obstetric components of the CDC 2010 guidelines, "Prevention of Perinatal Group B Streptococcal Disease: Revised Guidelines From CDC, 2010."
B族链球菌（GBS）是新生儿感染的主要原因。新生儿早发型GBS疾病（EOD）的主要危险因素是母亲泌尿生殖道和胃肠道的定植。约50%携带GBS的女性会将细菌传播给新生儿。垂直传播通常发生在分娩期间或胎膜破裂后。在没有产时抗生素预防的情况下，1%-2%的新生儿会发生GBS EOD。其他危险因素包括孕周小于37周、极低出生体重、胎膜早破时间延长、羊膜腔内感染、母亲年龄小以及母亲为黑人种族。有效预防GBS EOD所需的关键产科措施仍然包括通过阴道-直肠培养进行普遍产前筛查、正确的标本采集和处理、适当实施产时抗生素预防以及与儿科护理人员协调。美国妇产科医师学会现在建议在妊娠36 0/7至37 6/7周之间进行普遍的GBS筛查。所有在妊娠36 0/7 - 37 6/7周时阴道-直肠培养GBS呈阳性的女性，除非在胎膜完整的情况下进行临产前剖宫产，均应接受适当的产时抗生素预防。虽然推荐的产时抗生素使用时间较短不如4小时或更长时间的预防有效，但2小时的抗生素暴露已被证明可减少GBS阴道菌落计数并降低临床新生儿败血症诊断的频率。必要时，产科干预不应仅仅为了在出生前给予4小时抗生素而延迟。本委员会意见，包括[具体内容未给出]、[具体内容未给出]和[具体内容未给出]，更新并取代了美国疾病控制与预防中心2010年指南“围产期B族链球菌疾病的预防：美国疾病控制与预防中心2010年修订指南”中的产科部分。
