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.