孕妇生殖道B族链球菌感染与胎膜早破的关系及其对母婴预后和新生儿听力筛查的影响

目的:探讨孕妇生殖道B族链球菌(GBS)感染与胎膜早破(PROM)的关系及其对母婴预后和新生儿听力筛查的影响。方法:选取2017年1月到2019年1月期间在我院接受治疗的PROM患者100例作为PROM组,另选取同期住院的正常妊娠孕妇100例作为对照组,PROM组患者根据是否合并GBS感染分为GBS阳性组和GBS阴性组。比较PROM组和对照组的GBS阳性率,比较GBS阳性组和GBS阴性组早产、胎儿窘迫、新生儿窒息、新生儿肺炎、产褥感染的发生率及新生儿听力筛查的通过率。结果:PROM组的GBS阳性率高于对照组,差异有统计学意义(P0.05)。GBS阳性组早产、胎儿窘迫、新生儿窒息、新生儿肺炎、产褥感染的发生率均明显高于GBS阴性组,差异均有统计学意义(P0.05),GBS阳性组在初筛和复筛时听力筛查通过率均低于GBS阴性组,差异均有统计学意义(P0.05)。结论:孕妇生殖道GBS感染与PROM密切相关,并可增加不良妊娠结局发生的风险,在一定程度上影响了新生儿的听力功能,对母婴预后造成不良影响。     

生殖道GBS感染对妊娠晚期妇女阴道微生态环境及免疫因子的影响

探讨妊娠晚期生殖道B族溶血性链球菌（GBS）感染对阴道微生态环境及免疫因子的影响。

收集2021年7月至2022年7月本院76例GBS筛查阳性妊娠晚期妊娠妇女（GBS阳性组）,另选取同期GBS筛查阴性的76例妊娠晚期妊娠妇女（对照组）,比较2组阴道微生态情况、血清免疫炎症因子（IL-1β、IL-6）水平及妊娠结局;另根据阴道微生态评价结果将GBS阳性组妊娠妇女进一步分为微生态失调组（n=56）和微生态正常组（n=20）,比较2组妊娠结局。

GBS阳性组和对照组研究对象的阴道pH值、细菌性阴道病（BV）发生率、外阴阴道假丝酵母菌病（VVC）发生率、阴道菌群密集度、阴道菌群多样性及微生态失调发生率比较差异均有统计学意义（χ²=8.550、5.842、5.156、4.682、5.339、14.341,均P＜0.05）,2组研究对象滴虫性阴道炎发生率、阴道清洁度比较差异均无统计学意义（χ²=0.541、1.685,均P＞0.05）。GBS阳性组血清IL-1β、IL-6水平显著高于对照组（t=16.711、19.388,均P＜0.05）。GBS阳性组早产、产褥感染、胎儿窘迫及病理性黄疸发生率显著高于对照组（χ²=5.365、10.059、7.938、5.787,均P＜0.05）,2组研究对象胎膜早破、产后出血、新生儿窒息及新生儿肺炎发生率比较差异均无统计学意义（χ²=1.849、0.882、2.027、2.027,均P＞0.05）。微生态失调组胎膜早破、胎儿窘迫发生率显著高于微生态正常组（χ²=4.113、4.113,均P＜0.05）,2组研究对象早产、产褥感染、产后出血、新生儿窒息、病理性黄疸和新生儿肺炎发生率比较差异均无统计学意义（χ²=2.805、1.281、0.384、0.734、0.880、0.734,均P＞0.05）。

妊娠晚期GBS感染妊娠妇女易发生阴道微生态及炎症因子失调,增加不良妊娠结局发生风险。

     

妊娠期女性HPV感染及阴道微生态失衡对妊娠结局及新生儿的影响

探讨妊娠期女性人乳头瘤病毒（HPV）感染及阴道微生态失衡对妊娠结局及新生儿结局的影响,为该类患者的治疗提供参考。

选取2020年6月至2023年6月于我院产检的102例HPV阳性妊娠妇女（HPV阳性组）以及同期产检的78例HPV阴性妊娠妇女（HPV阴性组）为研究对象,于怀孕28～34周时,收集阴道分泌物评价阴道微生态状况;另根据微生态评价结果将HPV阳性组对象分为微生态正常组（n=26）和微生态失调组（n=76）;比较HPV阳性组与HPV阴性组对象阴道微生态情况、妊娠结局及新生儿结局,比较微生态正常组与微生态失调组对象妊娠结局及新生儿结局。

HPV阳性组和HPV阴性组对象滴虫性阴道炎（TV）和外阴阴道假丝酵母菌病（VVC）发生率、阴道清洁度比较差异均无统计学意义（χ²=1.520、0.678、0.111,均P＞0.05）,而阴道pH、细菌性阴道病（BV）发生率、阴道菌群密集度、阴道菌群多样性以及微生态失调发生率比较差异均有统计学意义（χ²=10.106、8.247、4.337、5.236、13.865,均P＜0.05）。HPV阳性组对象早产、宫内感染、产褥感染及产后出血发生率显著高于HPV阴性组（χ²=5.710、10.721、6.799、4.294,均P＜0.05）,而两组对象剖宫产率及胎膜早破发生率比较差异无统计学意义（χ²=1.067、0.666,均P＞0.05）。HPV阳性组新生儿感染发生率显著高于HPV阴性组（χ²=9.001,P＜0.05）,两组胎儿窘迫、新生儿窒息和胎儿宫内生长受限（FGR）发生率比较差异均无统计学意义（χ²=2.503、1.547、0.560,均P＞0.05）。微生态失调组对象早产发生率显著高于微生态正常组（χ²=4.130,P＜0.05）,而两组胎膜早破、宫内感染、产褥感染及产后出血发生率比较差异均无统计学意义（χ²=1.401、0.578、0.141、1.368,均P＞0.05）。微生态失调组与微生态正常组胎儿窘迫、新生儿窒息、FGR和新生儿感染发生率比较差异均无统计学意义（χ²=0.261、0.698、1.057、0.242,均P＞0.05）。

妊娠期HPV感染能引发阴道微生态失调,增加不良母婴结局发生风险。

     

B族链球菌感染妊娠妇女产时 抗生素治疗临床效果评价

目的探讨沈阳地区孕晚期妊娠妇女B族链球菌(group B Streptococcus,GBS)的定植率及其耐药性,评估GBS感染妊娠妇女分娩期给予产时抗生素预防(intrapartum antibiotic prophylaxis,IAP)的临床效果。方法选择2017年9月至2017年12月在沈阳市妇婴医院行GBS筛查的691例怀孕35～37周的妊娠妇女为研究对象,将GBS筛查阳性妊娠妇女中采用顺产方式分娩的38例妊娠妇女作为研究组,638例GBS筛查阴性妊娠妇女作为对照组。研究组妊娠妇女给予IAP,对照组妊娠妇女不作处理。分析两组妊娠妇女GBS定植情况、GBS菌株耐药情况及给予IAP后新生儿不良事件发生率。结果 691例妊娠妇女中有53例GBS培养阳性,GBS定植率为7.67%。全部GBS菌株对青霉素、头孢唑林及万古霉素的敏感率均为100.00%;对红霉素、克林霉素耐药率分别为81.48%和73.95%。研究组中新生儿黄疸发生率为7.89%,新生儿窒息发生率为2.63%,脑膜炎、肺炎、败血症的发生率均为0.00%。对照组中新生儿黄疸发生率为3.13%,新生儿窒息发生率为0.63%,肺炎发生率为0.16%,新生儿脑膜炎及败血症发生率均为0.00%。两组新生儿在新生儿黄疸、新生儿窒息、脑膜炎、肺炎和败血症发生率方面比较差异无统计学意义(均P0.05)。结论沈阳地区妊娠妇女GBS带菌率较高,青霉素可作为治疗的首选药物。预防性使用抗生素治疗可以改善新生儿结局。     

妊娠妇女阴道微生态和B族链球菌与胎膜早破及母婴结局的相关性

探讨妊娠妇女阴道微生态状况和B族链球菌（GBS）感染与妊娠晚期胎膜早破及母婴结局的相关性。

回顾性收集2021年1月至2022年12月我院114例临床确诊足月胎膜早破妊娠妇女为研究对象（胎膜早破组）,随机选取同期分娩的129例健康妊娠妇女为对照组。收集两组对象临床资料,比较两组对象阴道微生态变化、GBS感染及不良母婴结局发生情况。

两组妊娠妇女阴道假丝酵母菌菌体及孢子检出情况比较差异均无统计学意义（均P＞0.05）。胎膜早破组患者阴道pH≥4.5、细菌性阴道病、需氧菌性阴道炎的发生率及微生态失衡率高于对照组（均P＜0.05）。胎膜早破组妊娠妇女绒毛膜羊膜炎、产褥感染、胎儿窘迫及新生儿肺炎等不良母婴结局发生率高于对照组（均P＜0.05）。单因素分析结果显示,阴道pH≥4.5、有GBS感染、阴道微生态失调与不良母婴结局有关（均P＜0.05）。

妊娠晚期阴道微生态失衡、GBS感染与妊娠晚期胎膜早破的发生相关,同时会增加不良母婴结局的发生率。加强相关危险因素的干预可降低妊娠晚期女性胎膜早破发生率,改善不良母婴结局。

     

围产期孕妇生殖道B族链球菌感染高危因素分析及母婴结局探讨

目的调查沈阳地区围产期孕妇生殖道B族链球菌(group B streptococcus,GBS)定植率和感染高危因素及对母婴结局的影响,以便预防和控制围产期妇女GBS感染,优化母婴结局。方法对2017年9—11月在医院作孕期检查的31～40周孕晚期孕妇691例取阴道拭子及直肠拭子进行GBS培养、分离鉴定,分析GBS定植率;采用卡方检验进行GBS感染的单因素分析,采用多因素二元Logistic回归进行GBS感染的高危因素分析;对比两组孕妇及新生儿结局。结果沈阳地区孕晚期孕妇生殖道GBS定植率为7.67%(53/691),其中阴道试子阳性率为4.63%(32/691),直肠试子阳性率为6.22%(43/691);孕妇GBS感染的危险因素显示,在教育程度、生产史、分娩方式、甲状腺异常、妊娠期高血压、妊娠期贫血和妊娠期糖尿病,组间差异均无统计学意义(P>0.05);孕妇GBS感染危险因素,年龄、体质量、流产史和生殖道感染,组间比较,差异均有统计学意义(P<0.05);经多因素二元Logistic回归分析结果显示,年龄、体重、流产史和生殖道感染为影响GBS感染发生的独立危险因素,两组比较差异均有统计学意义(P<0.05);感染组孕妇胎膜早破、早产发生率高于对照组,经比较差异有统计学意义(P<0.05);产后出血发生率经比较差异无统计学意义(χ2=0.624,P>0.05);感染组新生儿胎儿窘迫、绒毛膜羊膜炎、新生儿黄疸发生率高于对照组,经比较差异有统计学意义(P<0.05)。结论沈阳市孕妇生殖道GBS定植率较高,建议对孕晚期孕妇开展GBS常规筛查。年龄、体重、流产史和生殖道感染为GBS感染发生的独立危险因素,有必要对本地区的围产期孕妇进行健康宣教,减少GBS感染的发生,进而改善母婴结局。     

妊娠期糖代谢异常对新生儿出生结局的影响

目的：探讨妊娠期不同程度的糖代谢异常对胎儿发育及结局的影响。方法：前瞻性收集我院2009年1月至2010年1月分娩的糖代谢异常的331例单胎妊娠孕妇,分为糖筛查异常组69例、糖耐量异常组126例、妊娠期糖尿病（Gestaional DiabetesMellitus,GDM）组136例,并选择同期糖代谢正常的751例单胎孕妇为对照组,比较四组新生儿出生的最终结局。结果：糖筛查异常组与对照组新生儿结局差异无显著性意义（P〉0.05）;糖耐量异常组中巨大儿及新生儿窒息、早产儿的发生率与对照组差异有显著性意义（P〈0.05）;GDM组与对照组差异有显著性意义（P〈0.05）。结论：母亲妊娠期不同程度的糖代谢异常对新生儿影响不同。口服葡萄糖耐量试验（Oral Glucose Tolerance Test,OGTT）异常与GDM一样对新生儿发育及结局均有影响,可使巨大儿、新生儿窒息、早产儿的发生率增高。     

围产期B族链球菌感染对妊娠结局的影响

目的:调查妊娠35~37周孕妇B族链球菌(GBS)带菌情况,探讨GBS感染与不良妊娠结局的关系。方法:收集妊娠35~37周孕妇265例,取阴道下段1/3分泌物和直肠分泌物,采用实时荧光定量PCR法进行GBS检测,观察其妊娠结局。结果:265例孕妇中GBS阳性者42例,阴性者223例,带菌率约为15.84%;GBS阳性孕妇的宫内感染、胎儿窘迫和新生儿肺炎发生率高于GBS阴性组(P0.05)。结论:围产期妇女GBS感染会导致宫内感染、胎儿窘迫及新生儿肺炎的发生率升高,对妊娠结局会产生不良影响。     

妊娠合并甲状腺功能减退症26例妊娠结局分析

目的：对妊娠合并甲状腺功能减退症进行分析,探讨其对母儿的影响,及孕期筛查甲状腺功能有无意义。方法：对我院26例妊娠合并甲减的临床资料进行回顾性统计分析。结果：26例妊娠合并甲减病例中有1例早产（孕33周）,其余25例患者维持至足月妊娠,其中剖宫产17例（65.38%）,合并妊娠期高血压疾病5例（19.23%）,妊娠期糖尿病3例（11.53%）,羊水胎粪污染3例（11.54%）,新生儿无先天性甲减。经过治疗后甲状腺功能减退孕妇的剖宫产率,糖尿病发生率、高血压疾病发生率、羊水粪染的发生率较对照组增加;但两组妊娠结局差异无统计学意义（P〉0.05）。结论：妊娠合并甲状腺功能减退症孕妇多种妊娠并发症的发病率高于正常孕妇,应加强对妊娠甲减的早期筛查及治疗,可有效降低不良妊娠结局,减少先天性甲低的出生。     

妊娠期生殖道B族链球菌感染患者阴道微生态、 血清炎性因子变化及母婴结局调查

目的探讨妊娠期生殖道B族链球菌(GBS)感染患者阴道微生态、血清炎性因子变化及其对母婴结局的影响。方法对482例妊娠妇女的临床资料展开回顾,统计妊娠期生殖道GBS感染情况,并将其分为感染组(GBS细菌培养阳性)和非感染组(GBS细菌培养阴性),其中感染组患者给予抗生素药物治疗。统计妊娠期生殖道GBS感染检出情况;分析并比较感染组与非感染组阴道微生态分布情况;检测感染组与非感染组及感染组治疗前后血清炎性因子的变化情况;统计感染组的治疗效果;分析并比较感染组与非感染组母婴结局情况;分析影响母婴结局的危险因素。结果医院收治的482例妊娠期患者中检出生殖道GBS细菌培养阳性68例,阳性率为14.11%。感染组的阴道微生态环境中GBS、白细胞酯酶、唾液酸酶、乙酰氨基葡萄糖苷酶、脯氨酸氨基肽酶、过氧化氢酶检出率均高于非感染组(均P0.05),阴道菌群密集度II～III度、乳杆菌、清洁度I～II级检出率低于非感染组(均P0.05)。感染组hs-CRP、PCT、IL-6含量均显著高于非感染组(均P0.05),感染组治疗后的C-反应蛋白(hs-CRP)、血清降钙素原(PCT)、白细胞介素-6(IL-6)含量显著低于治疗前(均P0.05)。统计感染组患者的治疗效果及不良事件,其中痊愈57例,好转11例,复发2例。感染组产后出血、宫内感染发生率与与非感染组比,差异无统计学意义(均P0.05),感染组早产、胎膜早破、羊水污染发生率均高于非感染组(均P0.05)。感染组围产儿肺炎、窒息发生率与非感染组比,差异无统计学意义(均P0.05),感染组围产儿宫内窘迫、生理性黄疸发生率均显著高于非感染组(均P0.05);母婴结局发生者高龄产妇、早产、胎膜早破、羊水污染、围产儿宫内窘迫、生理性黄疸、阴道微生态失衡、未抗感染治疗、GBS感染、hs-CRP升高、PCT升高、IL-6升高均高于未发生者(均P0.05),经Logistic回归分析证实均为危险因素(OR=5.540、3.347、6.495、7.036、7.199、5.275、3.093、5.436、5.942、4.683、5.013、5.703,均P0.05)。结论妊娠期生殖道GBS感染患者的阴道微生态菌群改变,血清炎性因子升高,可增加母婴不良结局的发生风险。     

妊娠期妇女生殖道大肠埃希菌感染与妊娠不良结局分析

目的探讨妊娠期妇女生殖道大肠埃希菌感染对妊娠不良结局的影响。方法回顾性分析2011年1月至2013年12月在石家庄市第四医院住院孕产妇共2 053例,进行阴道分泌物细菌培养,对大肠埃希菌培养阳性组与正常对照组的妊娠结局进行分析,以探讨妊娠合并生殖道大肠埃希菌感染与围产期并发症的关系。结果在2 053例围产期妇女中,无致病菌组（对照组）为1230例,大肠埃希菌培养阳性组（感染组）为103例,总患病率为5.02%。感染组与对照组的绒毛膜羊膜炎的发生率分别为78.64%、12.20%（P〈0.01）,产褥感染率分别为24.27%、3.41%（P〈0.01）,新生儿黄疸的发生率58.25%、12.36%（P〈0.01）,胎膜早破率分别为11.65%、10.57%（P〉0.05）,早产率分别为3.88%、3.09%（P〉0.05）,胎儿窘迫的发生率2.91%、2.76%（P〉0.05）,低体重儿的发生率1.94%、2.03%（P〉0.05）。结论妊娠期妇女生殖道大肠埃希菌感染与绒毛膜羊膜炎、产褥感染及新生儿黄疸的发生相关,孕期及早发现、诊断、治疗妊娠期妇女生殖道大肠埃希菌感染是有重要意义。     

妊娠晚期阴道B族链球菌的感染对肠道菌群和妊娠结局的影响

目的探究妊娠晚期阴道B族链球菌(group B Streptococcus,GBS)的感染对肠道菌群和妊娠结局的影响。方法选取2018年3月至2019年11月大连市中心医院孕检并分娩的妊娠妇女744人为对象,调查并统计B族链球菌的感染率;筛选有和没有B族链球菌感染妊娠妇女各47人,调查不良妊娠结局的发生率;选取信息匹配的妊娠晚期阴道B族链球菌感染和未感染的妊娠妇女,采集粪便样本,提取菌群DNA,用16S rDNA方法分析菌群变化。结果744名妊娠妇女中B族链球菌检出49例,感染率为6.59%;B族链球菌感染组总的不良妊娠发生比例为76.6%,正常组发生比例为27.7%(χ^2=5.491,P<0.05)。B族链球菌感染组妊娠妇女胎膜早破(χ^2=16.177,P<0.01)、难产(χ^2=21.134,P<0.01)和羊水异常(χ^2=22.989,P<0.05)的发生率与未感染组比较显著增高。B族链球菌感染组妊娠妇女肠道菌群发生显著变化。结论妊娠晚期阴道B族链球菌的感染可能引起肠道菌群紊乱,增加不良妊娠结局。     

Prevalence and significance of vaginal group B streptococcus colonization in pregnant women from Osijek, Croatia

The aim of the study was to determine the prevalence of vaginal group B streptococcus (GBS) colonization in pregnant women from Osijek area, the possible effect of GBS colonization on pregnancy outcome and neonatal complications and the role of intrapartum prophylaxis in this context. This retrospective case-control study took place at the Department of Gynecology and Obstetrics, Osijek University Hospital Center from December 2003 to June 2006. A total of 118 pregnant women was enrolled in study and divided into two groups: 59 women in 35th-37th week of gestation, free from risk factors for infection (control group); and 59 women in 25th-41st week of gestation with risk factors for infection. Low vaginal swab for GBS isolation and identification on selective and enriched medium was obtained from each woman. GBS colonization was recorded in 29 (24.6%) women: 12 (20.3%) control and 17 (28.8%) women at risk of infection, yielding a statistically non-significant difference (Chi2 = 1.480489; p < 0.48). Early neonatal infection was observed in six (20.7%) neonates born to 29 mothers with GBS colonization, pointing to a correlation between vaginal GBS colonization and early neonatal infection (r(s) = 0.99). Early perinatal infection was found in 22 (18.6%) neonates, including 17 (28.8%) pregnancies with risk factors, pointing to a significant correlation between vaginal GBS colonization, risk factors and early perinatal infection (Chi2 = 88.68; p < 0.001); however, gestational age and pregnancy outcome were not influenced by GBS colonization. In eight (36.4%) newborns, early neonatal infection developed in spite of intrapartum administration of antibiotics; three of these children were born to GBS positive mothers, and perinatal GBS infection was demonstrated in one (0.84%) child. Study results revealed a relatively high rate of GBS colonization in the population of pregnant women in Croatia, occasionally leading to early neonatal infection. Large studies are needed to develop national strategy for the prevention of GBS infection in Croatia.     

晚期孕妇生殖道感染无乳链球菌与新生儿感染的相关性研究

目的探讨妊娠晚期妇女生殖道感染无乳链球菌（GBS）与新生儿感染的关系。方法在慈溪市妇幼保健院1192例胎膜早破妊娠晚期妇女进行宫颈分泌物培养,同时对其分娩的1196个新生儿进行鼻咽分泌物培养作为观察组,同时选择同期无胎膜早破的妊娠晚期妇女500例作为对照组进行比较。观察胎膜早破合并GBS阳性妊娠晚期妇女与新生儿感染的相关性。结果观察组分离无乳链球菌比例为16．1％（192／1192）,对照组分离无乳链球菌比例为6．0％（30／500）,两组比较无乳链球菌感染与胎膜早破差异有统计学意义（P〈0．05）。早破合并GBS阳性的妊娠晚期妇女新生儿感染率与破膜时间和分娩产程有关,破膜时间〈24h与〉24h的妊娠晚期妇女,其新生儿感染率与破膜时间成正比,产程〈24h的妊娠晚期妇女新生儿感染率明显低于24h以上的妊娠晚期妇女。结论妊娠晚期妇女无乳链球菌感染与胎膜早破有关,从而引起新生儿感染,为了早期预防新生儿感染,应对GBS阳性的妊娠晚期妇女及时治疗,并严格控制早破时间和缩短分娩产程。     

Observation of the effect of the pregnancy complicated with the hepatitis B infection on the lying-in women and neonates

ObjectiveTo investigate the effect of pregnancy complicated with the hepatitis B infection on the pregnancy outcome, immunological factors and the subgroup of lymphocytes in neonates.MethodsSubjects admitting to this hospital between January 1, 2016 and January 1, 2018 in this study were divided into two groups according to the hepatitis B infection, i.e. the observation group (infection) and the control group (healthy), with 60 subjects in each group. Pregnancy complications and the neonatal complications were all recorded, and furthermore, the subgroups of lymphocytes and the levels of immunoglobin in the umbilical cord blood were measured.ResultsThe incidence rates of the premature rupture of fetal membranes, premature delivery, postpartum hemorrhage and pregnancy-induced hypertension syndrome in the observation group were all higher than those in the control group, and the differences had statistical significance. In the observation group, the incidence rates of the neonatal distress and asphyxia, and the levels of neonatal CD3^＋, CD4^＋, CD19^＋, IgA and IgM varied significantly from those in the control group, and the differences showed statistical significance. However, no significant differences were identified in comparison of the incidence rate of the cesarean delivery, neonatal deformity, neonatal death, or levels of neonatal CD8⁺ and IgG.ConclusionDuring pregnancy, complications of hepatitis B infection results in the increases in the incidence rates of the premature rupture of fetal membranes and neonatal asphyxia, with influences on the levels of immunological factors and lymphocyte subgroups in the umbilical cord blood.     

Effectiveness of intrapartum penicillin prophylaxis in preventing early-onset group B streptococcal infection: results of a meta-analysis.

OBJECTIVE: To determine the effectiveness of intrapartum penicillin prophylaxis in preventing early-onset group B streptococcal (GBS) infection in neonates of women whose birth canals are colonized by group B streptococci. DATA SOURCES: Articles published between 1966 and 1992 identified from MEDLINE, EMBASE, the Science Citation Index and the Oxford Perinatal Database; the bibliographies of primary studies, textbooks and review articles and published abstracts from major conferences and symposia. DATA SELECTION: Studies were selected if four criteria were met: (a) the target population was intrapartum women and neonates, (b) the intervention was penicillin prophylaxis, (c) invasive early-onset GBS infection was an outcome measure, and (d) the studies were controlled trials or cohort studies. Seven primary studies were identified, four of which were randomized controlled trials. DATA EXTRACTION: Explicit methodologic criteria were used by two of the authors to assess independently the study quality; one of the reviewers was blind as to author, institution and journal. The baseline characteristics of the population, intervention and outcome were summarized twice and checked for accuracy by two of the authors. DATA SYNTHESIS: Five of the studies showed a trend toward a beneficial effect of penicillin prophylaxis, and two showed a statistically significant effect. The pooled odds ratio indicated a 30-fold reduction (95% confidence interval 0.0013 to 0.17) in the incidence of early-onset GBS infection with intrapartum penicillin prophylaxis. Subgroup analyses did not change these results. The magnitude of improvement observed did not differ between women with prenatal risk factors (premature rupture of the membranes and premature labour) and those without these risk factors. CONCLUSIONS: There is accumulative evidence that intrapartum penicillin prophylaxis is effective in preventing early-onset GBS infection. Such therapy is beneficial to women whose birth canals are colonized with group B streptococci. Further studies are needed to determine the optimum timing and method of detecting vaginal colonization during pregnancy.