Vaginal progesterone is associated with decreased group B streptococcus colonisation at term: a retrospective cohort study

• Published in: BJOG : an international journal of obstetrics and gynaecology Vol. 126; no. 9; pp. 1141 - 1147
• Main Authors: Ma'ayeh, M, Rood, KM, Walker, HC, Oliver, EA, Gee, SE, Iams, JD
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 01-08-2019
• Subjects: 17‐alpha‐hydroxyprogesterone caproate; Administration, Intravaginal; Adult; Bacterial Load - drug effects; Birth; Chi-Square Distribution; Cohort analysis; Female; group B streptococcus; Health risk assessment; Humans; Infant, Newborn; infection; intramuscular; Logistic Models; Multivariate Analysis; Pregnancy; Premature birth; Premature Birth - microbiology; Premature Birth - prevention & control; Progesterone; Progesterone - administration & dosage; progestin; Progestins - administration & dosage; progestogen; Retrospective Studies; Statistics, Nonparametric; Streptococcus; Streptococcus agalactiae; Streptococcus agalactiae - growth & development; Streptococcus infections; Vagina; Vagina - microbiology; vaginal; group B streptococcus; infection; progestin; progesterone; intramuscular; 17-alpha-hydroxyprogesterone caproate; Streptococcus agalactiae; progestogen; vaginal
• ISSN: 1470-0328; 1471-0528
• DOI: 10.1111/1471-0528.15801

Objective
To investigate whether women using intravaginal progesterone suppositories for preterm birth prevention during pregnancy will have lower rates of group B streptococcus (GBS) colonisation at term, compared with women receiving intramuscular 17‐alpha‐hydroxyprogesterone caproate.
Design
This was a retrospective observational cohort study of women who were prescribed a progestogen during their pregnancy for preterm birth prevention, and who delivered at term.
Setting
A tertiary referral hospital in central Ohio.
Population
Patients who were prescribed a progestogen during their pregnancy for preterm birth prevention between 2004 and 2017 were included in the study. Patients who delivered at <37 weeks of pregnancy, switched progestogen type during the pregnancy, or had a pessary or cerclage placed were excluded.
Methods
Baseline characteristics were compared using Mann–Whitney U‐test or Chi‐square test as appropriate. The association between type of progestogen and GBS colonisation was assessed using bivariate and multivariable analyses.
Main outcome measures
The primary outcome was GBS colonisation.
Results
In all, 565 patients were included in the study, of whom 173 received intravaginal progesterone, and 392 17‐alpha‐hydroxyprogesterone caproate. Patients receiving intravaginal progesterone were less likely to be colonised with GBS (19.7 versus 28.1%). After adjustments for potential confounders were made in a multivariable logistic regression analysis, receiving intravaginal progesterone suppositories (adjusted odds ratio [OR] 0.61, 95% CI 0.39–0.95) was associated with reduced GBS colonisation.
Conclusions
Intravaginal progesterone is associated with a decreased prevalence of rectovaginal GBS colonisation at term.
Tweetable
Vaginal progesterone is associated with a lower incidence of rectovaginal GBS colonisation, compared with 17α‐hydroxyprogesterone caproate.
Tweetable
Vaginal progesterone is associated with a lower incidence of rectovaginal GBS colonisation, compared with 17α‐hydroxyprogesterone caproate.