Subclinical vaginal infections and adverse pregnancy outcome

Identification: Hansen, Anna


Subclinical vaginal infections and adverse pregnancy outcome
Hansen AS1, Maimburg RD1, Lindahl C1, Uldbjerg N1, Jensen JS2.
1Department of Obstetrics and Gynecology, Aarhus University Hospital, Aarhus, Denmark
2Department of Microbiology and Infection Control, Statens Serum Institut, Copenhagen, Denmark

Aim: We aimed to investigate if a) certain subclasses of bacterial vaginosis and b) vaginal colonization with the Chlamydia-like bacterium, Waddlia chondrophila are associated with increased risk of spontaneous abortion or spontaneous preterm birth.
Background: Bacterial vaginosis (BV) has been associated with preterm birth as well as early miscarriage. However, only a minority of women with BV experience these outcomes. A better understanding of differences in the microbial composition may identify subclasses of BV that impart a higher risk than others.
W. chondrophila is an intracellular bacterium of the Chlamydiales class. It has been associated with abortion in bovines and may be involved in the etiology of spontaneous abortion in humans.

Materials and methods: An ongoing prospective cohort study including two cohorts; a) 1400 unselected pregnant women enrolled at 12 weeks of gestation (GA) and b) 330 pregnant women admitted with symptoms like bleeding and pain in early pregnancy, enrolled at a median of 7+5 weeks of GA. At inclusion, we obtained vaginal swabs and vaginal smears from all participants. The vaginal smears were Gram stained and classified according to the Nugent criteria for BV. The vaginal swabs will be examined for selected BV associated bacteria using species-specific quantitative PCR assays. Waddlia chondrophila will be identified using PCR. Pregnancy outcomes were collected from the electronic birth files. We used Fisher's exact test and chi-squared test for statistical analysis.
Preliminary results: Among the unselected pregnant women, 5% (57/1148) had BV (Nugent score ≥ 7) and 10% (114/1148) had intermediate scores (Nugent score 4-6). Within this cohort, 4.6% (56/1218) gave birth before 37+0 weeks of GA. This figure was 2.1% (3/144) among those with BV and 5.3% (46/871) among women without BV (OR 0.38; 95% CI 0.12 - 1.24).
Among the 330 women with symptoms in early pregnancy, 4.6% (3/65) had BV and 17% (11/65) women had intermediate scores. In this cohort, 62% (185/298) had a spontaneous abortion. This figure was 57% (8/14) among those with BV and 49% (25/51) among those without BV (OR 1.38; 95% CI 0.42 - 4.5)

Results from PCR analysis for BV associated bacteria and Waddlia chondrophila are pending and will be presented at the conference.
Funding sources: Danish Medical Research Council and Aarhus University


Credits: None available.