It is unclear if the use of probiotics or antibiotics affects pregnancy outcomes.BV is the most common vaginal infection in women of reproductive age. The percentage of women affected at any given time varies between 5% and 70%. BV is most common in parts of Africa and least common in Asia and Europe. In the United States about 30% of women between the ages of 14 and 49 are affected. Rates vary considerably between ethnic groups within a country. While BV-like symptoms have been described for much of recorded history, the first clearly documented case occurred in 1894. Signs and symptoms
Although about 50% of women with BV are asymptomatic, common symptoms include increased vaginal discharge that usually smells like fish. The discharge is often white or gray in color. There may be burning with urination. Occasionally, there may be no symptoms.The discharge coats the walls of the vagina, and is usually without significant irritation, pain, or erythema (redness), although mild itching can sometimes occur. By contrast, the normal vaginal discharge will vary in consistency and amount throughout the menstrual cycle and is at its clearest at ovulation—about two weeks before the period starts. Some practitioners claim that BV can be asymptomatic in almost half of affected women, though others argue that this is often a misdiagnosis.
Amsel criteria
In clinical practice BV can be diagnosed using the Amsel criteria:
Thin, white, yellow, homogeneous discharge
Clue cells on microscopy
pH of vaginal fluid >4.5
Release of a fishy odor on adding alkali—10% potassium hydroxide (KOH) solution.At least three of the four criteria should be present for a confirmed diagnosis. A modification of the Amsel criteria accepts the presence of two instead of three factors and is considered equally diagnostic. Gram stain
An alternative is to use a Gram-stained vaginal smear, with the Hay/Ison criteria or the Nugent criteria. The Hay/Ison criteria are defined as follows:
Grade 1 (Normal): Lactobacillus morphotypes predominate. Grade 2 (Intermediate): Some lactobacilli present, but Gardnerella or Mobiluncus morphotypes also present. Grade 3 (Bacterial Vaginosis): Predominantly Gardnerella and/or Mobiluncus morphotypes. Few or absent lactobacilli. (Hay et al., 1994)Gardnerella vaginalis is the main culprit in BV. Gardnerella vaginalis is a short, Gram-variable rod (coccobacillus). Hence, the presence of clue cells and gram variable coccobacilli are indicative or diagnostic of bacterial vaginosis. Nugent score
The Nugent score is now rarely used by physicians due to the time it takes to read the slides and requires the use of a trained microscopist. A score of 0-10 is generated from combining three other scores. The scores are as follows:
0–3 is considered negative for BV
4–6 is considered intermediate
7+ is considered indicative of BV.At least 10–20 high power (1000× oil immersion) fields are counted and an average determined. DNA hybridization testing with Affirm VPIII was compared to the Gram stain using the Nugent criteria.