摘要目的:探讨孕妇妊娠晚期B族链球菌(group B streptococcus，GBS)筛查和实施产时抗生素预防(intrapartum antibiotic prophylaxis，IAP)对新生儿早发型GBS感染的影响，分析新生儿早发型GBS感染的高危因素，并了解其预后情况。方法:回顾性选取2012年7月至2019年6月在温州医科大学附属第二医院新生儿科住院的新生儿早发型GBS感染患儿为病例组，随机抽取同期孕母有GBS定植新生儿无早发型GBS感染患儿为对照组；比较2016年7月开展GBS筛查和IAP策略前后本院出生新生儿早发型GBS感染的发生率；分析不同分娩方式下新生儿早发型GBS感染的高危因素。结果:病例组纳入43例，对照组纳入182例，两组胎龄、出生体重比较差异无统计学意义( P>0.05)。2016年7月至2019年6月开展GBS筛查和IAP策略后，本院共出生35 717例新生儿，新生儿早发型GBS感染2例，发生率为0.056‰，较2012年7月至2016年6月(0.277‰，9/32 511)下降了80%，差异有统计学意义( P<0.05)。病例组阴道分娩36例，多因素Logistic回归分析显示，阴道分娩患儿母亲体温≥38℃( OR＝6.812)、胎膜早破≥18 h( OR＝12.247)、无IAP( OR＝16.881)是新生儿早发型GBS感染的危险因素，充分IAP是新生儿早发型GBS感染的保护因素( OR＝0.180， P<0.05)。病例组剖宫产7例，其中6例有胎膜早破。43例早发型GBS感染新生儿中单纯败血症11例，均治愈；败血症合并化脓性脑膜炎11例，死亡2例(18.2%)，存活9例，随访1～6年，其中4例存在神经系统后遗症。 结论:对孕妇开展GBS筛查和IAP措施可有效降低新生儿早发型GBS感染的发生率。剖宫产前如胎膜已破或已临产，GBS可经产道逆行感染导致新生儿早发型GBS感染。新生儿GBS败血症合并化脓性脑膜炎者病死率和神经系统后遗症发生率高，预后差。

abstractsObjective:To study the effects of group B streptococcus(GBS)screening in late pregnancy and intrapartum antibiotic prophylaxis (IAP) on neonatal early-onset GBS infection, and to analyze the risk factors and prognosis of the disease.Method:From July 2012 to June 2019, newborns with early-onset GBS infection hospitalized in the neonatal ward of our hospital were selected as the case group, and the newborns without GBS infection born to mothers who had GBS colonization during the same period were randomly assigned into the control group. GBS screening and IAP strategy were implemented in our hospital since July 2016. The incidences of neonatal early-onset GBS infection before and after July 2016 were compared, and the high-risk factors of early-onset GBS infection with different delivery modes were analyzed. Chi-square test, non-parametric test, and Logistic regression analysis were used for statistical analysis. Result:A total of 43 cases in the case group and 182 cases in the control group were enrolled. No significant differences existed in gestational age and birth weight between the two groups ( P>0.05). From July 2016 to June 2019, after the implementation of GBS screening and IAP strategy, a total of 35 717 newborns were born in our hospital, and 2 newborns had early-onset GBS infection. The incidence was 0.056‰, which was 80% lower than the incidence from July 2012 to June 2016 (0.277‰, 9/32 511), the difference was statistically significant ( P<0.05). 36 cases were naturally delivered. Multivariate Logistic regression analysis showed that maternal body temperature ≥38℃ ( OR=6.812), premature rupture of membranes (PROM) for more than 18 hours ( OR=12.247) and non-IAP ( OR=16.881) were risk factors for early-onset GBS infection, while sufficient IAP was a protective factor for the disease ( OR=0.180, P<0.05). 7 cases received cesarean section, 6 of which had PROM. Among 43 newborns of early-onset GBS infection, 11 newborns with septicemia but without meningitis were cured and their prognosis were good. 11 cases had meningitis, 2 of them died (18.2%), and the 9 survivors were followed up for 1~6 years and 4 had neurological sequelae. Conclusion:GBS screening and IAP strategy for pregnant women can effectively reduce the incidence of neonatal early-onset GBS infection. PROM and threatened labor before cesarean section may cause GBS retrograde infection through the birth canal and lead to early-onset GBS infection. Neonatal GBS septicemia with meningitis has higher rates of neurological sequelae, mortality and poor prognosis.