Prevalence and significance of group B Streptococcus in a large obstetric population.

Between Jan. 1 and Dec. 31, 1985, vaginal swabs were obtained for culture for group B beta-hemolytic Streptococcus (GBS) from 3078 women admitted for labour and delivery to Regina General Hospital. Seventy-one women had positive results; thus, the colonization rate was only 2.3%. The charts of the 71 women and their 73 babies were analysed. Of the 58 babies from whom swabs were obtained, 20 had GBS at one or more sites; the transmission rate was therefore 34%. Early-onset GBS disease developed in one infant. Two infants died within the first month; however, death was not directly attributable to GBS. Higher rates of preterm delivery and of low birth weight were noted among the babies of the colonized women than among the babies of all women admitted for labour and delivery in 1985. Given the low rate of GBS disease in our centre, we suggest that emphasis be placed on GBS as a possible source of obstetric complications such as preterm labour.