Objective: To investigate the screening strategy of group B streptococcus (GBS) in the reproductive tract of women in the third trimester and analyze its impact on pregnancy outcome. Methods: A total of 85 461 pregnant women in 35-37 weeks of gestation from Bao'an Maternity and Child Health Hospital, Jinan University from January 2011 to June 2018 were enrolled. They were divided into 3 periods according to different GBS screening strategies, the unscreened period included 31 384 cases (36.72%), 33 267 cases (38.93%) were included in partial screening period, 20 810 cases (24.35%) were included in screening period. All GBS screening positive pregnant women were given intrapartum antibiotic prophylaxis (IAP). The impact on pregnancy outcomes, and the impact of different GBS collection transport and culture methods on the positive rate of GBS screening were analyzed. Results: (1) The incidence of neonatal early onset GBS disease (EOGBSD) in unscreened period was 0.03% (11/31 773), in partial screening period was 0.02%(6/33 887), and in screening period, the incidence of neonatal EOGBSD decreased to 0, the difference was statistically significant (χ(2)=7.86, P=0.02).(2) The incidence of hematogenous infection of GBS in pregnant women was 0.02%(6/33 887) in partial screening period, and there was none in screening period, there was no significant difference (adjusted χ(2)=3.75, P=0.05). (3) In the screening period, the positive rate of GBS was 14.08%(2 719/19 306), which was significantly higher than the positive rate of GBS in the partial screening period (11.48%, 2 058/17 920; χ(2)=56.12, P=0.00). (4) Antibiotic sensitivity tests of 4 777 GBS strains showed that the antibiotics with higher resistance rate were tetracycline (81.52%, 3 896/4 777), erythromycin (66.59%, 3 181/4 777), and clindamycin (64.31%, 3 072/4 777). The combination of erythromycin, clindamycin and tetracycline was the most common resistant pattern, accounting for 48.80% (2 331/4 777). No penicillin, ceftriaxone or vancomycin resistant strains was found. Conclusions: GBS screening strategy in different regions could combine the local neonatal EOGBSD incidence rate, maternal GBS colonization rate, and the socioeconomic factors to determine whether universal GBS screening or screening for high-risk maternal women. GBS screening positive rate is related to the population, scope of the investigation, the sample collection, delivery and culture methods. The multi-drug resistance rate of GBS is high.
目的： 探讨妊娠晚期孕妇生殖道B族链球菌（GBS）的筛查策略及分析其对妊娠结局的影响。 方法： 收集2011年1月至2018年6月于暨南大学附属深圳市宝安区妇幼保健院进行产前检查并分娩的孕妇共85 461例，根据不同的生殖道GBS筛查策略（筛查者均为妊娠35~37周）按时间段分为3个时期，未筛查期31 384例（36.72%），部分筛查期33 267例（38.93%），筛查期20 810例（24.35%）；所有GBS筛查结果阳性的孕妇均给予产时抗菌素预防（IAP）。分析不同GBS筛查策略对妊娠结局的影响，并分析采用不同的GBS样本处理方法对GBS筛查阳性率的影响及GBS耐药性的变化。 结果： （1）未筛查期孕妇的新生儿早发性GBS疾病（EOGBSD）的发生率为0.03%（11/31 773），部分筛查期为0.02%（6/33 887），筛查期为0，三者比较，差异有统计学意义（χ(2)=7.86，P=0.02）。（2）部分筛查期孕妇分娩期GBS血源性感染的发生率为0.02%（6/33 887），筛查期为0，两者比较，差异无统计学意义（校正χ(2)=3.75，P=0.05）。（3）筛查期孕妇生殖道GBS的筛查阳性率为14.08%（2 719/19 306），显著高于部分筛查期者（11.48%，2 058/17 920；χ(2)=56.12，P=0.00）。（4）4 777株GBS药敏结果显示，耐药率较高的抗菌药物分别为四环素81.52%（3 896/4 777），红霉素66.59%（3 181/4 777），克林霉素64.31%（3 072/4 777）；红霉素、克林霉素和四环素联合耐药模式最常见，占48.80%（2 331/4 777），未发现青霉素、头孢曲松或万古霉素耐药菌株。 结论： 各地区可结合当地新生儿EOGBSD的发生率和孕妇生殖道GBS的阳性率，及社会、经济学因素，制定是否对高危孕妇进行GBS筛查及普遍筛查方式；GBS筛查的阳性率与筛查人群范围及样本处理方法均相关；GBS的多重耐药率高。.
Keywords: Neonatal sepsis; Pregnancy outcome; Pregnancy trimester, third; Prenatal diagnosis; Streptococcal infections; Streptococcus agalactiae.