[Relationship of group B streptococcus colonization in late pregnancy with perinatal outcomes]

To investigate the relationship of group B streptococcus (GBS) colonization in late pregnancy with perinatal outcome.

Pregnant women who underwent antenatal check-up at General Hospital of PLA Eastern Theater Command and the First Affiliated Hospital of Nanjing Medical University from January 2016 to December 2018 were enrolled in the study. The vaginal and rectal swab samples were collected for GBS culture at 35-37 weeks of pregnancy. The perinatal outcomes of positive and negative GBS groups were compared. The GBS-positive group samples were tested for antibiotic susceptibility. In GBS positive group the maternal and child perinatal outcomes were compared between pregnant women with antibiotics treatment and those without antibiotics.

A total of 13 000 pregnant women were enrolled, and the overall colonization rate of GBS was 3.65%(475/13 000). The colonization rate of GBS in the vagina was 2.33%(303/13 000), and the colonization rate in the rectum was 1.75%(227/13 000). Through the collection and detection of rectal specimens, the positive rate of GBS increased by 56.77%(172/303). The monthly colonization rate of GBS showed significant fluctuations with the highest in March and October (all P < 0.05). The sensitivity of 475 GBS-positive specimens to ceftriaxone, vancomycin and linezolid were 100%, and the sensitivity to ampicillin and penicillin were 97.26%and 93.47%, respectively. The resistance rates of the strains to levofloxacin, clindamycin, erythromycin and tetracycline were 30.11%, 48.00%, 52.21%and 88.63%. The incidence of premature rupture of membranes, postpartum hemorrhage, puerperal infection, neonatal pneumonia and sepsis in GBS positive group were significantly higher than those in GBS negative group (all P < 0.01). In pregnant women with positive GBS, the incidence of puerperal infection, neonatal infection and admission to the NICU in the antibiotic group were significantly lower than those in the non-antibiotic group ( P < 0.05 or P < 0.01).

The total colonization rate of GBS is low. The detection of GBS can be significantly improved by supplementing rectal examination. Ceftriaxone, ampicillin and penicillin are currently the drugs of choice for the prevention and treatment of GBS-related diseases. GBS infection can increase the incidence of maternal and child complications. The use of antibiotics during labor can improve the outcome of mothers and infants.