Search strategy

The meta-analysis was conducted following the PRISMA guidelines (Moher et al., 2010). Studies were identified through a systematic search of MEDLIINE, PUBMED, WANGFANG, and CNKI, from January 1979 to April 2016, using the following searching terms: (“group B streptococcus” or “streptococcus agalactiae”) and (“antibiotic” or “anti-bacterial agents” or “intrapartum antibiotic prophylaxis”) and (“perinatal period” or “pregnant women”). In addition, reference lists of all retrieved articles and previous systematic reviews were checked for further eligible publications. We restricted our search to studies performed in human studies and published in English or Chinese.