Abstract: Objective: To validate and discuss the efficacy of clinical protocol for prevention of Group B streptococcal（GBS） disease in women with premature rupture of membranes （ＰＲＯＭ） according to the guidelines of 2010 CDC. Methods: A retrospective cohort study of 394 women with PROM admitted at the Suzhou Municipal Hospital between Jan. 2016 and Feb. 2016, including 84 women with preterm premature rupture of membranes（PPROM） and 310 women with PROM in term labor. All women were managed according to the protocol for PROM in 2010 CDC guidelines, also refer to the two strategy in previous guidelines based on culture and risk factors to conduct the intrapartum antibiotic prophylaxis（ＩＡＰ）. The GBS colonization rate and the incidence of early-onset group B streptococcal disease（EOD） in the two groups were compared, respectively. The effect of IAP on the incidence of EOD was also analyzed. Results: The rate of GBS colonization in the PPROM group was higher than that in the PROM group（11.9% vs. 4.8%， χ2=5.55，P＝0.018）. In the PROM group, GBS colonization is a risk factor for PPROM（OR=2.658, 95%CI:1.148-6.155）. The difference of the incidence of EOD between the PPROM group and the PROM group was not significant（2.38% vs. 0.65%，χ2＝1.98，P=0.159）. There was not an infected newborn in those PROM mother with the complete IAP（0/212）, while the incidence of EOD in those women who underwent inadequate IAP or no IAP was 2.25%（4/178）（χ2＝4.71，P=0.03）, suggesting that the complete IAP is the protective factor for EOD（OR=0.456，95%CI：0.410-0.509）. Conclusions: It is necessary to screen and manage those women with PROM, to conduct the IAP strictly according to the guidelines, and to notice those primary risk factors in which the premature delivery is the most notable factor.

Key words: Streptococcus agalactiae, Fetal membranes, premature rupture, Infant, newborn, Bacterial infections, Antibiotic prophylaxis