An observational study to estimate the probability of pregnant women, who were GBS-negative in the first trimester of pregnancy become GBS-positive at the end of pregnancy. It is an observational. One hundred pregnant women in the first trimester of pregnancy (11 ± 2 weeks) will be invite to participate in this prospective study. If accept, a vagino-rectal swab will collected for a GBS detection analysis. When negative, participants will be follow by their gynecologist with the normal routine procedures. During 35 week of pregnancy a vagino-rectal swab will be collected and analyzed to detect GBS. Then, a final visit will be completed one month after delivery.

Healthy pregnant women reporting to the clinic in their first trimester of pregnancy (week 11 ± 2 weeks of pregnancy) will be asked to participate in this study. Participation will be voluntary and written informed consent will be obtained from each participant. The study visits will take place in the hospital.

At Visit 1, the inclusion and exclusion criteria will be verified. After signing the informed consent, a physical examination will be performed in addition to a vaginal-rectal swab to detect if they are GBS-negative. Information on the demographic profile and medical history will be collected. The investigator will explain to the participant that she cannot use any probiotic during the course of the study.

At Visit 2, within 21-23 weeks ± 4 days of gestation, the inclusion and exclusion criteria will be reviewed. If the result of the microbiological analysis of the vaginal-rectal exudate is negative, the pregnant women shall continue in the study. A physical examination will be performed. Adverse Events occurring from the time of study inclusion will be recorded.

At the third visit (Visit 3, 35 weeks ± 4 days of gestation), all participants continuing in the study will undergo a general physical examination. A sample of vagino-rectal exudate will be collected. Adverse Events occurring during the period between Visit 2 and Visit 3 will be recorded.

During Visit 4 (1 month after delivery), all participants will have a general physical examination. Adverse Events occurring since Visit 3 will be recorded. Data will be collected on the delivery and occurrence of early- or late-onset GBS sepsis in the newborn during the first month of life.

Inclusion Criteria:

Healthy pregnant women, adults (≥ 18 years and under 45 years). Before/during week 13 of gestation. Signing of informed consent.

Exclusion Criteria:

Multiple pregnancy.

Fetal complications.

History of premature delivery/miscarriage in the second trimester. Significant maternal medical complications.

HIV-positive.

Women who are immunocompromised (for example, patients with cancer and transplant who are taking certain immunosuppressive drugs, patients with hereditary diseases that affect or could affect the immune system).

History of significant gastrointestinal disease (e.g., prior gastrointestinal resection, current diarrhea, inflammatory bowel disease).

Heart failure and cardiac medical history (e.g. artificial heart valve, medical history of infective endocarditis, rheumatic fever or cardiac malformation).

Use of other probiotics during the current pregnancy.

Uncertainty of the investigator regarding the willingness or capacity of the participant to comply with the requirements of the protocol.

Women

100 pregnant women GBS (-)