Having a vaginal discharge can be embarrassing. However, it's a very common symptom, and can be easily treated.

In women who are having des règles, bacterial vaginosis (BV) is the most common cause of a vaginal discharge.

Qu'est-ce que la vaginose bactérienne ?

BV is a disturbance in the mix of harmful bacteria in the vagina. Normally there is a healthy mix of millions of 'friendly' germs (bacteria) in our bodies, including in the vagina - we rely on them being there and they are a part of what keeps us healthy. In BV, the balance of vaginal bacteria is altered.

The type of bacteria called anaerobic bacteria (bacteria that grow in an environment without air) increase in number, whilst another type, called lactobacilli, dies off. This disturbance in the bacteria makes the inside of the vagina slightly less acidic than usual. This slight reduction in acidity then encourages the growth of more anaerobic bacteria and fewer lactobacilli.

Although the changes of BV don't usually cause pain or itching, they do tend to cause a discharge which can smell stronger than usual. Sometimes it smells 'fishy', particularly after sexual activity. It can be watery and greyish in colour.

This can be distressing and make women feel unclean. Some women then try to douche or wash themselves with soaps or perfumes - but this will only disturb the vagina more (because soaps are too alkaline for the inside of the vagina) and will make the problem worse.

BV is a common condition, but we don't know exactly how often it occurs. It's been suggested that 1 in 3 women get BV at least once in their lives. But estimating this is difficult, as it is often so mild that women may not go to the doctor.

Bacterial vaginosis is a common condition of the vagina caused by an overgrowth of various germs. It is not one infection, caused by one type of germ.

The vagina normally has a mix of germs (bacteria), including anaerobic bacteria and lactobacilli, but in bacterial vaginosis (BV) the balance changes. As a result, the anaerobic bacteria multiply and thrive much more than usual. In other words, they are bacteria which are normally present, just not in the same balance.

BV is pas caused by poor hygiene. In fact, excessive washing of the vagina (particularly if strong soaps or perfumed deodorants are used) may alter the normal balance of bacteria in the vagina even more, which may make BV more likely to develop or worsen.

We don't really know what triggers the bacterial balance to 'swing' away from normal. We know that it's more likely to happen if something disturbs the acidity of the vagina, (acidity which is CAUSED by the normal bacteria), which then allows the anaerobic bacteria to overgrow.

Acidity is measured on the pH scale in which lower numbers are more acidic and higher numbers are more alkaline. The normal pH of the vagina is 3.8-4.5.

As soon as the pH increases above 4.5, anaerobic bacteria start to overgrow and lactobacilli (which maintain the acidity) start to die off.

You are more likely to get BV:

• If you are sexually active. Women who have never had sex can get BV too. However, it is more common in women who are having sex. You can have BV whether you have sex with women or with men:

  • Women who have sex with women are more likely to get BV. This is because they tend to share the same make-up of bacteria in the vagina.

• If you have recently changed your sexual partner. Frequent changes of sexual partner, or having more than one regular partner, increase the likelihood of BV further.

• If you have a past history of sexually transmitted diseases (STDs).

• If you smoke.

• If you have a copper coil for contraception - an intrauterine contraceptive device (the coil).

• If you are a Black woman. Black women are more likely to get BV. It's not clear why. There might be several reasons, like differences in bacteria in the vagina, exposure to stress, and being more likely to use vaginal douching.

• If you use bubble bath.

• If you have prolonged or les règles abondantes.

• Following hormonal changes. In some women BV seems to be triggered by the hormonal changes of puberty, pregnancy or the ménopause. These are all conditions of changing vaginal acidity.

• Following courses of antibiotics. Courses of antibiotics tend to kill off all our good bacteria (although le muguet, also called candida, is a more common complication after courses of antibiotic).

Other conditions which can upset vaginal pH or lactobacillus health, and which might be expected to increase the risk of BV include:

• Use of sex toys.

• Too much washing around the vagina - once a day is enough.

• Douching or using vaginal deodorants.

• Use of perfumed lubricants during intercourse.

• Wearing thongs or nylon tights for long periods.

• Prolonged or heavy periods.

You are less likely to get BV if:

• You use the pilule contraceptive orale combinée (COC).

• Your male partner has had a circumcision.

• You use condoms (which protect the vagina from the alkaline semen).

• You have showers, not baths.

No. BV can affect any woman, including those who do not have (or who have never had) sex or those who have multiple sex partners. However, BV is more common amongst sexually active women than amongst non-sexually active women.

A woman can't 'catch' BV from intercourse with a man, but BV is more likely to develop after a change in sexual partner, as - for reasons we don't really understand - this can affect the balance of normal germs (bacteria) in the vagina.

Women who have sex with other women are more likely to get BV. This is probably because women can exchange vaginal bacteria during sex. Women who have sex with women are also more likely to give and receive oral sex, and to share sex toys - both of which are linked with BV.

The main symptom of BV is a vaginal discharge. BV is the most common cause of vaginal discharge in women of childbearing age. Often, BV causes no symptoms. This is true in about half of the women who have the condition. This may be because the bacterial disturbance is only mild.

When BV causes symptoms, this is usually a change in vaginal discharge. Some women will also notice the characteristic smell.

• The discharge is often white or grey in colour and often has a fishy smell.

• The smell may be more noticeable during sex.

• The discharge tends to be heaviest just after a period, or after sex.

• The discharge does not usually cause itch or soreness around the vagina and vulva.

Remarque: BV is not the only cause of a vaginal discharge. Various conditions can cause discharge, such as le muguet (vaginal infection by overgrowth of a yeast called candida, which normally lives in the bowel) and IST.

• Thrush typically causes a thickish white or grey discharge which tends to cause itching and soreness around the vagina and vulva. See the separate leaflet called Vaginal Thrush for more details.

• IST, such as chlamydia and gonorrhoea, may also cause vaginal discharge. See the separate leaflets on Chlamydia et Gonorrhée pour plus de détails.

BV should not cause vaginal bleeding, although it is often more noticeable at the time of a period.

If you have unusual bleeding between periods or after intercourse, BV will not be the reason and you should consult your doctor to look for another cause.

BV can sometimes cause pain - usually on intercourse. Some women also describe dull pains low down in their tummy. These are more suggestive of conditions affecting the womb (uterus) itself, such as une maladie inflammatoire pelvienne ou endometriosis.

In certain circumstances, having bacterial vaginosis can cause complications, such as:

BV and surgery

If you have untreated BV, the chance of developing an infection of the womb is slightly higher following certain operations (such as termination of pregnancy or a vaginal hysterectomy). You will normally be offered treatment for the BV in these cases.

BV and other infections

Untreated BV may slightly increase the risk of you acquiring HIV infection if you have sex with someone who has HIV. This is probably because the normal acidity of the vagina helps protect against STIs.

If you have HIV and BV together then you are slightly more likely to pass on the HIV.

Women with untreated BV may be at a slightly increased risk of developing pelvic inflammatory disease. See the separate leaflets called VIH et SIDA et Pelvic Pain in Women pour plus de détails.

BV and pregnancy

BV can affect pregnancy. If you have untreated BV during pregnancy, you have a slightly increased risk of developing some health problems, including:

• Early labour.

• Fausse couche.

• Having your baby early (preterm birth).

• Having a low-birth-weight baby.

• Developing an infection of the womb after childbirth (a condition known as postpartum endometritis).

For this reason, if you develop bacterial vaginosis in pregnancy you will usually be offered treatment. This also means that if you develop an unusual or offensive discharge in pregnancy, you should seek medical advice early.

Subfertilité

BV is more common in women who are having problems getting pregnant. In women with BV who are undergoing IVF treatment, the presence of BV lowers the success rates. The studies which found these effects focused on women who were already known to have fertility problems, to see if they were more likely than other women to have BV.

This doesn't mean that if you have BV, you will have fertility problems: BV is extremely common (possibly a third of all women of menstrual age) and fertility problems which result in a need for in vitro fertilisation (IVF) are not common.

This suggests that the chances that BV will affect your fertility are very low. Even so, if you are planning to conceive in the future and you think you may have BV, you should see your doctor and discuss the best options for treatment.

If you have typical symptoms, and a sexually-transmitted infection is unlikely, your doctor or nurse may be happy to diagnose BV based solely on your symptoms.

The typical discharge and its characteristic fishy smell make BV likely. When your doctor examines you they may be able to identify BV from the appearance of the discharge.

There are some tests that can help to confirm the diagnosis. Also, if you are pregnant, it is important to make an accurate diagnosis of any unusual vaginal discharge so that any infection can be treated effectively. The tests include:

Testing the acid level of your vagina

The discharge of BV has a typical pH level (acidity level) which is higher than normal vaginal pH.

pH is measured on a scale from 0 (extreme acidity) to 14 (extremely alkaline). Pure water, which is neutral (neither acid nor alkaline) has a pH of 7.

• The normal pH of the vagina is 3.8-4.5.

• As soon as the pH increases above 4.5, anaerobic bacteria start to overgrow and lactobacilli (which maintain the acidity) start to die off.

Your doctor or nurse may suggest that they take a sample of your discharge and test it with some pH paper. You can buy a kit from a pharmacy to do this test yourself at home.

Taking a sample

To confirm the diagnosis of BV, your doctor or nurse may suggest that a sample (a swab) of your discharge be taken from your vagina and sent to the laboratory for examination and testing.

The various types of germs (bacteria) that overgrow in BV are easily seen under the microscope. Your doctor or nurse may suggest that they take more than one swab from your vagina to rule out other causes of vaginal discharge; for example, a test for chlamydia and gonorrhoea.

There are various different treatments for BV. There are also some things which you should avoid doing, which may help the problem to resolve itself.

These include avoiding the use of douches, vaginal deodorants, bath additives and harsh soaps. Refraining from intercourse for a couple of weeks, or using a condom and a water-based lubricant, can be helpful.

Antibiotiques pour la vaginose bactérienne

Oral antibiotics are the first-choice treatment in pregnant women with BV.

Comprimés de métronidazole
A full course of comprimés de métronidazole is the common treatment. Metronidazole is an antibiotic. This clears BV in most cases. It is important to read the leaflet that comes with these tablets for the full list of possible side-effects and cautions. The main points to note about metronidazole include:

• La dose habituelle est de 400-500 mg deux fois par jour pendant 5-7 jours. Une dose unique de 2 grammes de métronidazole est une alternative, bien que cela puisse être moins efficace et entraîner plus d'effets secondaires. (Remarque: cette dose unique n'est pas recommandée si vous êtes enceinte.) Il est important de terminer le traitement qui vous a été prescrit et de ne pas manquer de comprimés.

• Certaines personnes se sentent malades ou peuvent vomir lorsqu'elles prennent du métronidazole. Cela est moins probable si vous prenez les comprimés juste après un repas. Un goût métallique est également un effet secondaire courant.

• Ne consommez pas d'alcool pendant la traitement par métronidazole, ni pendant 48 heures après l'arrêt du traitement. L'interaction du métronidazole avec l'alcool peut provoquer de graves nausées et vomissements, ainsi que des bouffées de chaleur et une augmentation du rythme cardiaque.

• Le métronidazole peut passer dans le lait maternel en petites quantités, mais il ne nuira pas à votre bébé, bien qu'il puisse modifier le goût du lait. Le fabricant recommande, si vous allaitez, de suivre un traitement de 5 à 7 jours avec une dose plus faible de métronidazole plutôt qu'une seule dose importante.

Other possible antibiotic treatments
Tinidazole tablets may be offered if you know you are intolerant of metronidazole. Tinidazole is a similar antibiotic and you need to take 2 g once a day for two days, or 1 g once a day for five days.

It has the same interaction with alcohol that is seen with metronidazole, meaning that alcohol should not be consumed whilst you are taking it, nor for 48 hours afterwards. Tinidazole is not recommended in pregnancy.

Gel vaginal au métronidazole ou crème vaginale à la clindamycine placed inside the vagina can be used if you prefer this type of treatment, or if you experience unpleasant side-effects with metronidazole tablets. These treatments are believed to be almost as effective as antibiotics by mouth.

Remarque: comme avec les comprimés de métronidazole, vous devriez éviter l'alcool pendant l'utilisation du gel de métronidazole et pendant au moins 48 heures après l'arrêt du traitement, bien que la tendance des gels à vous donner des nausées ne soit pas aussi prononcée que pour les comprimés.

Vaginal creams and gels can weaken latex condoms and diaphragms. Therefore, during treatment and for five days after treatment with clindamycin vaginal cream, do not rely on condoms or diaphragms to protect against pregnancy and STIs.

Other antibiotic tablets taken by mouth are also sometimes used in treating BV. These are comprimés de clindamycine ou comprimés de tinidazole.

Yoghurt

Some women with BV say that things settle more quickly and symptoms are eased by applying a thin coat of plain, live yoghurt to the outside of the vagina daily, and by applying a small amount of plain live yoghurt on a tampon for internal use before bed.

The evidence that live yoghurt is helpful in treating or preventing BV is mixed, with some trials saying that it is helpful and some saying that it is not helpful. Overall specialists feel that there is not enough evidence in its favour to suggest it over other treatments.

Astodrimer sodium gel

Astodrimer sodium gel is a new kind of treatment for BV. It can be bought without a prescription online as Betafem® BV gel. It treats BV by creating a physical barrier that repels bacteria from coming close to and sticking to the vaginal wall.

A 2019 trial showed that astodrimer gel once daily for seven days was well tolerated by women and provided rapid improvement in BV symptoms. Patients improved, or were cured at the same rate as with conventional antibiotics.

Vaginal acetic and lactic acid

Treatment with acetic and lactic acid gels aims to keep the vaginal pH at less than 4.5, to encourage lactobacilli to grow, and to discourage anaerobic bacteria from growing. Some studies have suggested that long-term use of vaginal acidifiers of this type reduces recurrences of BV. However, other studies suggest that this treatment, whilst harmless, is not effective.

Lactobacillus tablets

Les suppositoires et comprimés oraux de Lactobacillus sont vendus dans certains magasins d'aliments naturels, pour traiter la vaginose bactérienne (VB).

Orally consumed probiotics are believed to reach the vagina via the bowel. There is some evidence that this can be helpful in treatment and in prevention of BV. These studies suggest treatment needs to continue for at least two months. Other studies don't show a clear benefit. Overall, specialists feel that there is not enough evidence in its favour to suggest it over other treatments.

Le traitement intravaginal de lactobacilles semble être une solution évidente — pourquoi ne pas mettre les bonnes bactéries là où elles doivent aller ? Cependant, les résultats des études sur les traitements vaginaux avec des lactobacilles sont également mitigés, certaines suggérant que ce traitement est efficace et d'autres non.

The body is often very good at getting back its own balance. The disruption in the balance of vaginal germs (bacteria) that causes BV may correct naturally, with time. So, if you have no symptoms or only mild symptoms, you may not need any treatment, particularly if you take some of the general healthy steps above.

You normally need treatment for BV if it is causing symptoms, or if the characteristic smell is noticeable to you. If you are pregnant, trying to become pregnant, or about to have a gynaecological procedure then you may be advised to get treatment for BV.

Grossesse

If you are pregnant and you are found to have BV then you will usually be offered un traitement antibiotique with oral metronidazole (see below).

Si vous essayez de concevoir et que vous pensez avoir une vaginose bactérienne, il est conseillé d'essayer de l'éliminer par des méthodes naturelles ou un traitement avant de concevoir. Si vous avez des symptômes, vous devriez en parler à votre médecin pour un traitement antibiotique.

Interruption de grossesse

Si vous êtes diagnostiquée avec une vaginose bactérienne et que vous subissez une interruption de grossesse, un traitement antibiotique peut être conseillé même si vous ne présentez aucun symptôme. En effet, il existe un risque que la vaginose bactérienne provoque une infection de l'utérus ou du pelvis après la procédure. Cela pourrait entraîner des problèmes de fertilité ultérieurs.

Procédures gynécologiques

Antibiotics are not usually recommended for women with BV (and no symptoms) who are about to undergo 'minor' gynaecological procedures such as an biopsie de l'endomètre - a biopsy of the lining of the womb. In fact women having these procedures are in any case not usually tested for BV, so they would not know they had it.

Les femmes subissant une hystérectomie vaginale reçoivent des antibiotiques avant la procédure, même si elles n'ont pas de vaginose bactérienne, afin de réduire le risque d'infection postopératoire. Ces antibiotiques élimineront également toutes les bactéries responsables de la vaginose bactérienne.

Il n'existe aucune preuve que traiter un partenaire sexuel masculin empêche sa partenaire féminine de développer une vaginose bactérienne. Une petite étude a examiné si l'utilisation d'un gel alcoolisé stérilisant sur le pénis protégeait leurs partenaires contre la vaginose bactérienne - mais le gel semblait rendre la vaginose plus courante, plutôt que moins, chez les femmes.

Si vous avez une partenaire féminine, il semble que la traiter pour la vaginose bactérienne en même temps que vous - même si elle n'a pas de symptômes - permettra d'éviter une récidive (chez l'un ou l'autre).

Femmes qui ne sont pas enceintes

Après le traitement, vous n'avez pas besoin d'autres tests pour confirmer que la vaginose bactérienne a disparu (test de contrôle) à condition que vos symptômes aient disparu.

Femmes enceintes

Si vous êtes enceinte, il est conseillé de faire un test un mois après le traitement pour s'assurer que la vaginose bactérienne n'est plus présente. Un échantillon (un écouvillon) des sécrétions de votre vagin est prélevé. Celui-ci est testé pour vérifier que vous n'avez plus de vaginose bactérienne.

If you have persistent BV (ie it does not settle down with the first treatment you try) then your doctor may want to take further vaginal swabs to check whether there is another cause for the discharge. They will usually suggest that you use the seven-day course of metronidazole if you have not had this before.

Un autre traitement qui peut être essayé est l'utilisation de gel de métronidazole deux fois par semaine pendant jusqu'à six mois.

If you have a persistent BV infection which does not respond to treatment, and you have an intrauterine contraceptive device (IUCD) then your doctor may advise removing the device until things settle down, as there is some evidence that IUCDs can contribute to persistent BV.

If you have persistent BV and a same-sex partner then treating both of you at the same time is likely to be helpful in preventing persistence and recurrence - even if your partner does not have symptoms.

The following are thought to help prevent some episodes of BV. The logic behind these tips is to try not to upset the normal balance of germs (bacteria) in the vagina:

• Ne poussez pas d'eau dans votre vagin pour le nettoyer (douche vaginale). Le vagin n'a pas besoin de nettoyage spécifique.

• Ne pas ajouter d'huiles de bain, d'antiseptiques, de savons parfumés, de bains moussants parfumés, de shampoings, etc., dans l'eau du bain.

• Ne pas utiliser de détergents puissants pour laver vos sous-vêtements.

• Ne lavez pas trop souvent autour de votre vagin et de votre vulve. Une fois par jour suffit généralement, en utilisant des savons doux et de l'eau.

• Ne pas utiliser de produits d'hygiène intime parfumés.

• Utiliser un préservatif et/ou un lubrifiant à base d'eau pendant les rapports peut vous aider à vous protéger.

• Évitez d'utiliser des jouets sexuels à l'intérieur du vagin.

• Évitez les strings et les collants en nylon moulants.

• Prendre des douches plutôt que des bains.

• Des règles plus légères semblent réduire la probabilité de réapparition de la vaginose bactérienne, donc si vous avez des règles abondantes et envisagiez de consulter un professionnel, cela pourrait être une autre raison de le faire.

La vaginose bactérienne revient souvent, généralement dans les quelques mois suivant le traitement — mais si certains comportements qui peuvent la déclencher (comme l'utilisation de douches vaginales) vous concernent, il est moins probable qu'elle réapparaisse si vous évitez ces pratiques.

La vaginose bactérienne revient souvent après traitement. Aucune solution efficace n'a encore été trouvée pour empêcher cela.

Si vous continuez à présenter des symptômes de vaginose bactérienne, votre médecin effectuera des tests pour être absolument certain que vous avez une vaginose bactérienne et non une autre infection. Si le diagnostic confirme la vaginose bactérienne, un antibiotique différent de celui que vous avez déjà pris pourra être essayé. Parfois, l'utilisation régulière prophylactique d'un gel vaginal antibiotique peut être recommandée.

If you are using an DIU for contraception, it may be advised that you consider having this removed.

If your symptoms come back and you did not have a test using a sample (a swab) of your vaginal discharge taken initially, your doctor or nurse may suggest that they take swab tests now. This is to confirm that it is BV causing your symptoms.

BV may return if you did not complete your course of antibiotics. However, even if you have completed a full course of antibiotics, BV returns within three months in many women. If it does come back, a repeat course of antibiotics will usually be successful. A small number of women have repeated episodes of BV and need repeated courses of antibiotics.

Astodrimer sodium gel also prevents recurrent BV and associated symptoms. In a 2019 study astodrimer sodium significantly reduced BV recurrence rates. You can buy astodrimer sodium gel (brand name Betafem® BV gel) online and do not need a prescription.

If you have a copper coil for contraception - an IUCD - and have recurrent BV, your doctor or nurse may suggest that they remove your IUCD to see if this helps to improve your symptoms. You will need to consider alternative contraception measures.

If you have a same-sex partner then, even if they have no symptoms, treating both of you at the same time may reduce recurrence.

You should also take particular notice of the advice not to use douches, bath additives and vaginal deodorants. Long-term use of metronidazole gel is sometimes advised. Specialist guidelines in the USA recommend using twice-weekly for up to six months. UK specialist guidelines are less certain on the frequency and duration of preventative treatment, and your doctor may want to talk with a specialist for advice on this.

Dr Mary Lowth est l'auteur ou l'auteur original de ce dépliant.