title: Role of Lactobacillus Species in the Intermediate Vaginal Flora in Early Pregnancy: A Retrospective Cohort Study.
abstract: BACKGROUND
  Poor obstetrical outcomes are associated with imbalances in the vaginal flora. The present study evaluated the role of vaginal Lactobacillus species in women with intermediate vaginal flora with regard to obstetrical outcomes.
  
  
  METHODS
  We retrospectively analysed data from all women with singleton pregnancies who had undergone routine screening for asymptomatic vaginal infections at our tertiary referral centre between 2005 and 2014. Vaginal smears were Gram-stained and classified according to the Nugent scoring system as normal flora (score 0-3), intermediate vaginal flora (4-6), or bacterial vaginosis (7-10). Only women with intermediate vaginal flora were investigated. Women with a Nugent score of 4 were categorised into those with and without Lactobacilli. Follow-up smears were obtained 4-6 weeks after the initial smears. Descriptive data analysis, the Welch's t-test, the Fisher's exact test, and multiple regression analysis with adjustment for confounders were performed. Gestational age at delivery and birth weight were the outcome measures.
  
  
  RESULTS
  At antenatal screening, 529/8421 women presented with intermediate vaginal flora. Amongst these, 349/529 (66%) had a Nugent score of 4, 94/529 (17.8%) a Nugent score of 5, and 86/529 (16.2%) a Nugent score of 6. Amongst those with a Nugent score of 4, 232/349 (66.5%) women were in the Lactobacilli group and 117/349 (33.5%) in the Non-Lactobacilli group. The preterm delivery rate was significantly lower in the Lactobacilli than in the Non-Lactobacilli group (OR 0.34, CI 0.21-0.55; p<0.001). Mean birth weight was 2979 ± 842 g and 2388 ± 1155 g in the study groups, respectively (MD 564.12, CI 346.23-781.92; p<0.001). On follow-up smears, bacterial vaginosis rates were 9% in the Lactobacilli and 7.8% in the Non-Lactobacilli group.
  
  
  CONCLUSIONS
  The absence of vaginal Lactobacillus species and any bacterial colonisation increases the risks of preterm delivery and low birth weight in women with intermediate vaginal flora in early pregnancy.
authors.affiliation: Department of Obstetrics and Gynaecology, Division of Obstetrics and Fetomaternal Medicine, Medical University of Vienna, Vienna, Austria.
authors.forename: Alex
authors.initials: A
authors.lastname: Farr
authors.affiliation: Department of Obstetrics and Gynaecology, Division of Obstetrics and Fetomaternal Medicine, Medical University of Vienna, Vienna, Austria.
authors.forename: Herbert
authors.initials: H
authors.lastname: Kiss
authors.affiliation: Section for Medical Statistics, Centre of Medical Statistics, Informatics and Intelligent Systems, Medical University of Vienna, Vienna, Austria.
authors.forename: Michael
authors.initials: M
authors.lastname: Hagmann
authors.affiliation: Department of Obstetrics and Gynaecology, Division of Obstetrics and Fetomaternal Medicine, Medical University of Vienna, Vienna, Austria.
authors.forename: Susanne
authors.initials: S
authors.lastname: Machal
authors.affiliation: Department of Obstetrics and Gynaecology, Division of Obstetrics and Fetomaternal Medicine, Medical University of Vienna, Vienna, Austria.
authors.forename: Iris
authors.initials: I
authors.lastname: Holzer
authors.affiliation: Department of Obstetrics and Gynaecology, Division of Obstetrics and Fetomaternal Medicine, Medical University of Vienna, Vienna, Austria.
authors.forename: Verena
authors.initials: V
authors.lastname: Kueronya
authors.affiliation: Department of Obstetrics and Gynaecology, Division of Obstetrics and Fetomaternal Medicine, Medical University of Vienna, Vienna, Austria.
authors.forename: Peter Wolf
authors.initials: PW
authors.lastname: Husslein
authors.affiliation: Department of Obstetrics and Gynaecology, Division of Obstetrics and Fetomaternal Medicine, Medical University of Vienna, Vienna, Austria.
authors.forename: Ljubomir
authors.initials: L
authors.lastname: Petricevic
mesh_terms: D001724:Birth Weight; D036861:Delivery, Obstetric; D005260:Female; D005500:Follow-Up Studies; D005865:Gestational Age; D006801:Humans; D007778:Lactobacillus / Q000502:physiology*; D015999:Multivariate Analysis; D011247:Pregnancy; D012189:Retrospective Studies; D014621:Vagina / Q000382:microbiology*; D014626:Vaginal Smears