Factors related to elevated vaginal pH in the first trimester of pregnancy

Objective. To assess different bacterial and epidemiological factors associations with increased vaginal pH in the pregnant women population during the first trimester. Design. A cross-sectional, observational study. Setting. Three outpatient clinics in Riga. Population. From July 2009 until January 2010, 139 unselected consecutive pregnant women at the first prenatal visit. Methods. Pregnant women were submitted to an interview, vaginal examination and vaginal specimen collection for pH measurement and native microscopy. Main outcome measures. Vaginal pH >= 4.5 was considered as elevated. Abnormal bacterial microflora was classified according to Donders. Results. Elevated vaginal pH was significantly associated with bacterial vaginosis (p < 0.001), aerobic vaginitis (p < 0.001) and mixed aerobic vaginitis and bacterial vaginosis flora (p < 0.001) and presence of sperm cells in the smears (p = 0.024). Most cases with sperm were associated with abnormal vaginal flora. Normal lactobacillary morphotypes were more often found in the pH <= 4.4 group (p < 0.001), while leptosomic and short types were found more frequently with increased pH. Conclusions. Elevated vaginal pH is associated with different types of abnormal vaginal flora and the presence of sperm cells.