Background:

A pregnant woman rectally or vaginally colonized by group B Streptococcus can infect her newborn.

Patients and methods:

Prospective, cross-sectional, analytical 24-month study in pregnant women. Women in labor with ≥ 36 weeks of gestation were included. Pregnancy was classified as normal or high-risk. Main risk factors of the pregnant women were analyzed. Rectal and vaginal samples were obtained, placed in Todd-Hewitt broth and subsequently inoculated in 5 % sheep blood agar. Identification was carried out by biochemical tests and latex agglutination.

Results:

3,347 pregnant women were included. Mean age was 25.6 ± 5.3 years, 95.5 % received antenatal care; 2,213 (66 %) had normal-risk pregnancies, and in 1,370 (41 %), delivery was by cesarean section. Overall colonization was 4.3 % (145/3,347), and it was higher in the 30-34 years age group (6.8 %). Serotype I (58 %) was the most common.

Conclusion:

The percentage of colonization in this population was low. A routine cervicovaginal and rectal culture program in pregnant women and the intrapartum antimicrobial prophylaxis program are controversial in our region.