Bacterial vaginosis is associated with overgrowth of Gardnerella vaginalis and decreased lactobacilli. What pH change is typical?

Bacterial vaginosis is associated with overgrowth of Gardnerella vaginalis and decreased lactobacilli. What pH change is typical?

• A. pH > 4.5
• B. pH < 3.5
• C. pH 4.0-4.5
• D. pH unchanged

Answer: (A)

The main concept is that bacterial vaginosis disrupts the acidic vaginal environment. Lactobacilli normally keep the vagina acidic by producing lactic acid, with a typical pH around 3.8–4.5. When Gardnerella vaginalis overgrows and lactobacilli decrease, less lactic acid is produced, so the environment becomes less acidic. This raises the pH above 4.5 (often toward neutral). So the typical pH change is a rise to greater than 4.5. This alkaline shift helps anaerobes thrive and is a diagnostic clue alongside findings like clue cells and a fishy odor.

The main concept is that bacterial vaginosis disrupts the acidic vaginal environment. Lactobacilli normally keep the vagina acidic by producing lactic acid, with a typical pH around 3.8–4.5. When Gardnerella vaginalis overgrows and lactobacilli decrease, less lactic acid is produced, so the environment becomes less acidic. This raises the pH above 4.5 (often toward neutral). So the typical pH change is a rise to greater than 4.5. This alkaline shift helps anaerobes thrive and is a diagnostic clue alongside findings like clue cells and a fishy odor.