Tests for Bacterial Vaginosis

Test Overview

Tests for bacterial vaginosis take samples of fluid from the vagina. The samples are looked at under a microscope to see if they show signs of infection.

Bacterial vaginosis is caused by a change in the balance of bacteria in the vagina. Normally, there are a lot of "good" bacteria and some "bad" bacteria in the vagina. The good types help control the growth of the bad types. But when you have bacterial vaginosis, there are not enough good bacteria and too many bad bacteria.

Many women with bacterial vaginosis don't have symptoms. The most common symptom is an increase in vaginal discharge. The discharge often has a fishy smell.

Women who have this problem during pregnancy have a higher chance of miscarriage, early delivery, and an infection after delivery. So it's important for pregnant women with symptoms to be tested.

Tests

Tests for bacterial vaginosis include:

• Wet mount. A sample of vaginal discharge is checked for bacteria, white blood cells, and unusual cells called clue cells. If clue cells are present, it means you may have bacterial vaginosis.
• Whiff test. A sample of discharge is checked to see if a strong fishy odor is created when a special solution is added. A fishy odor usually means you have bacterial vaginosis.
• Vaginal pH. The pH of a sample of vaginal discharge is measured. Bacterial vaginosis often causes a pH that is higher than normal.
• Oligonucleotide probe. A sample of vaginal discharge is tested for the genetic material, or DNA, of this bacteria. This test is not often used.