Fetal fibronectin and microorganisms in vaginal fluid of healthy pregnant women

Objective. To determine fetal fibronectin in vaginal fluid from healthy women during uncomplicated pregnancy and to investigate possible relationships to gestational age and the vaginal microflora. Materials and methods. Samples of vaginal fluid were collected for fetal fibronectin determination and for quantitative aerobic and anaerobic microbiological culture from 22 women followed longitudinally at 12, 28 and 37 weeks gestation and cross-sectionally in women at 12 weeks (n=10), 28 weeks (n=10), 37 weeks (n=10), and 39 weeks (n=30) gestation, respectively. Fetal fibronectin was determined by a quantitative enzyme immunoassay (Adeza Biomedical). Results. There were no significant differences between the concentrations of fetal fibronectin in vaginal secretions at any of the four measurement points (12, 28, 37 and 39 weeks gestation). Women with elevated fetal fibronectin concentration (greater than or equal to 0.05 mg/L) had less often hydrogen peroxide-producing facultative lactobacilli (p<0.0001), and more often bacterial vaginosis (p<0.02) and Peptostreptococcus species (p<0.002). Bacterial vaginosis (p<0.01) and Candida albicans (p<0.01) were more frequently found in women lacking hydrogen peroxide-producing lactobacilli. Conclusion. Fetal fibronectin in vaginal fluid was more associated with the vaginal microflora than with the gestational age of the pregnancy. Presence of hydrogen peroxide-producing lactobacilli seems to be the most important factor for a stable vaginal microflora.