[B-streptococci in obstetrics--risks and consequences of maternal colonization and neonatal contamination].

2,373 mothers and their newborn were studied during two years with respect to B streptococci colonisation or contamination. Bacteriological, vaginal and anal smears were taken from mothers at the beginning of parturition, as well as the amnion and the aspirated stomach contents of the newborn, employing, in each case, conventional culture methods and a latex agglutination test as a rapid testing method. Smears from the ears were also taken from the newborn for bacteriological examination. The vertical transmission and its possible influencing variables were examined in 1,328 mother/child pairs of the first observation year. Surface contamination of the newborn was confirmed in 10% in at least one smear. In the group of mothers with B streptococci colonisation, the amnion showed the highest rate of contamination (43%), followed by the aspirated stomach contents (26%) and the ear smears (taken from each side separately) with 28% and 30% respectively. Vertical transmission was decisively influenced by vaginal maternal colonisation (50% of the cases resulting in contamination of newborn), whereas anal colonisation, if it was the only site of colonisation, resulted in contamination of newborn in only 32% of the cases. The rate of contamination of newborn dropped significantly from 50% to 20% after intrapartal antibiotic prophylaxis, the latter appearing to be meaningful only after at least 6 hours of exposure. In this group, the surface contamination could be reduced from 61% to 8%. A group of newborn suffering from early onset of sepsis (0.4%), was compared with a group of 13 newborn at risk of infection (0.9%) with established surface contamination and clinical or laboratory chemistry confirmation of infection.(ABSTRACT TRUNCATED AT 250 WORDS)