蒙、汉族孕妇B族链球菌定植及新生儿早发型败血症状况的研究

Study on colonization of Group B Streptococcus in pregnant women of Mongolian and Han nationality and the status of neonatal early-onset septicemia

目的探讨蒙汉族孕妇B族溶血性链球菌(GBS)带菌状况及其分娩新生儿GBS感染情况,以明确该地区蒙汉族新生儿GBS感染的高危因素。方法以2017年6月至2020年6月在内蒙古医科大学附属医院进行GBS检测并娩出活产新生儿的7289例孕妇及其分娩的新生儿为研究对象进行GBS培养,并取GBS阳性产妇所分娩的新生儿静脉血进行抗GBS荚膜多糖抗体水平检测,以明确新生儿GBS感染的高危因素。结果(1)7289例孕妇中包括蒙古族孕妇3136例(足月产2599例,早产537例),汉族孕妇4153例(足月产3541例,早产612例)。GBS检测结果显示:蒙古族早产组孕妇GBS带菌率为8.19%,足月组孕妇GBS带菌率为4.35%,汉族早产组孕妇GBS带菌率为11.93%,足月组孕妇GBS带菌率为5.76%,提示无论蒙古族与汉族,早产组孕妇GBS带菌率均明显高于足月组,差异均有统计学意义(P<0.05)。进一步对比蒙汉族孕母GBS带菌率发现,无论早产组与足月组,蒙古族孕妇GBS带菌率均低于汉族孕妇GBS带菌率,差异均有统计学意义(P<0.05)。(2)GBS阳性产妇所分娩的新生儿共434例,蒙古族早产儿GBS阳性率为29.55%,足月儿GBS阳性率为14.16%,汉族早产儿GBS阳性率为31.51%,足月儿GBS阳性率为17.65%,提示无论蒙古族与汉族,早产儿GBS阳性率均明显高于足月儿,差异有统计学意义(P<0.05)。进一步对比蒙汉族新生儿GBS阳性率发现,无论早产组与足月组,蒙古族新生儿GBS阳性率与汉族相比,差异无统计学意义(P>0.05)。(3)本次研究对比了蒙汉族新生儿早发型GBS败血症发生率,结果显示蒙古族早产儿发生新生儿早发型GBS败血症的发生率为23.08%,足月儿中无患儿发生该病,汉族早产儿发生新生儿早发型GBS败血症的发生率为26.09%,足月儿发生新生儿早发型GBS败血症的发生率为5.56%,结果提示无论蒙古族与汉族,早产组新生儿GBS败血症发生率均明显高于足月组,差异有统计学意义(P<0.05)。进一步对比蒙汉族新生儿GBS败血症发生率发现,无论早产组与足月组,蒙古族新生儿GBS阳性率与汉族相比,差异无统计学意义(P>0.05)。(4)无论蒙古族与汉族,早产儿组抗GBS荚膜多糖抗体水平均明显低于足月儿组,差异有统计学意义(P<0.05)。(5)无论蒙古族与汉族,与GBS阴性者相比,孕妇年龄≥35岁、伴经产史、流产史、阴道炎、流动人口、未行孕前检查者GBS阳性率较高,是孕期孕妇GBS阳性的高危因素。(6)无论蒙古族与汉族,与GBS阴性组相比,GBS阳性孕妇绒毛膜羊膜炎、产褥感染、早产及胎膜早破的发生率增加,其新生儿发生胎儿窘迫及新生儿窒息的几率亦增高,差异有统计学意义(P<0.05)。结论蒙古族孕妇GBS带菌率低于汉族孕妇,且孕期GBS阳性将会增加绒毛膜羊膜炎、产褥感染、早产、胎膜早破、胎儿窘迫、新生儿窒息及新生儿早发型GBS败血症等母婴不良妊娠结局发生率,其高危因素有孕妇年龄≥35岁、伴经产史、流产史、阴道炎、流动人口、未行孕前检查者感染等,应高度重视围产期的高危因素并根据高危因素制订相应干预措施,合理使用抗生素进行产时预防,以进一步降低新生儿早发型GBS败血症的发生率。

Objective To explore the carrier status of group B streptococci(GBS)in pregnant women of Mongolian and Han nationality and the neonatal GBS infection in order to identify the high risk factors of GBS infection in Mongolian and Han newborns in this area.Methods Totally 7289 pregnant women and their newborns born alive were tested for GBS in the Affiliated Hospital of Inner Mongolia Medical University from June 2017 to June 2020,and their newborns were cultured for GBS,and the venous blood of newborns delivered by GBS positive women were detected for anti-GBS capsular polysaccharide antibody level,in order to determine the high risk factors of neonatal GBS infection.Results Among the 7289 pregnant women,3136 were Mongolian pregnant women(2599 full-term delivery and 537 premature delivery)and 4153 were Han pregnant women(3541 full-term delivery and 612 premature delivery).The results of GBS test showed that the GBS carrier rate was 8.19%in the Mongolian preterm delivery group,4.35%in the Mongolian term group,11.93%in the Han preterm group,and 5.76%in the Han term group,indicating that the carrier rate of GBS in the preterm group was significantly higher than that in the term group,regardless of Mongolian and Han nationality(P<0.05).Further comparing the GBS carrier rate of Mongolian and Han pregnant women,the GBS carrier rate of Mongolian pregnant women was significantly lower than that of Han pregnant women regardless of the premature delivery group and term group(P<0.05).(2)A total of 434 newborns were born by GBS positive parturients.The positive rates of GBS in Mongolian premature infants,Mongolian full-term infants,Han premature infants and Han full-term infants were 29.55%,14.16%,31.51%and 17.65%,respectively,suggesting that the positive rate of GBS in premature infants was significantly higher than that in full-term infants,regardless of Mongolian and Han nationality(P<0.05).Further comparing the positive rate of GBS in Mongolian and Han newborns,there was no significant difference in the positive rate of GBS between Mongolian newborns and Han newborns,no matter the premature delivery group and the full-term group.(3)This study compared the incidence of early-onset GBS septicemia in Mongolian and Han newborns.The results showed that the incidence of early-onset GBS septicemia in Mongolian premature infants was 23.08%,and none in full-term infants.The incidence of early-onset GBS septicemia in Han premature infants was 26.09%.The incidence of early-onset GBS septicemia in term infants was 5.56%.The incidence of neonatal GBS septicemia in the preterm group was significantly higher than that in the term group,regardless of Mongolian and Han nationality.By further comparing the incidence of GBS septicemia in Mongolian and Han newborns,there was no significant difference in the positive rate of GBS between Mongolian newborns and Han newborns regardless of the premature delivery group and the term group.(4)In both Mongolian and Han nationality,the level of anti-GBS capsular polysaccharide antibody in premature infants was significantly lower than that in term infants(P<0.05).(5)Regardless of the Mongolian and Han nationality,compared with GBS negative group,GBS positive rate was higher in pregnant women aged≥35 years old,with history of menstruation,miscarriage,vaginitis,floating population,and those who had not undergone pre-pregnancy examination,,which were the high risk factors for GBS-positive pregnant women during pregnancy.(6)In both Mongolian and Han nationality,the incidence of chorioamnionitis,puerperal infection,premature delivery and premature rupture of membranes in the GBS positive group was higher than that in the GBS negative group,and the incidence of fetal distress and neonatal asphyxia in the GBS positive group was also higher than that in the GBS negative group.Conclusions The carrier rate of GBS in Mongolian pregnant women is lower than that in Han pregnant women,and positive GBS during pregnancy will increase the incidence of adverse maternal and fetal outcomes such as chorioamnionitis,puerperal infection,premature delivery,premature rupture of membranes,fetal distress,neonatal asphyxia and neonatal early-onset GBS septicemia.The high risk factors are maternal age≥35 years old,history of menstruation,abortion,vaginitis,floating population,and infection without pre-pregnancy examination.We should attach great importance to the perinatal high risk factors and formulate corresponding intervention measures accordingly,and make rational use of antibiotics for prenatal prevention,so as to further reduce the incidence of early-onset GBS septicemia in newborns.