Bacterial vaginosis in pregnancy: What you need to know

What is bacterial vaginosis?

Bacterial vaginosis is the most common vaginal infection in women between the ages of 15 to 44. It's common among pregnant women, possibly because of the hormonal changes that take place.

Our bodies contain an array of good bacteria that help keep us healthy. The vagina is colonised by bacteria called lactobacilli which help to keep everything in check and prevent harmful germs (pathogens) from getting inside.

Sometimes, however, the balance of these bacteria can change - and bacteria other than lactobacilli can overgrow in the vagina, causing symptoms such as unusual discharge. This is called bacterial vaginosis or BV.

Dr Krishna Vakharia, a GP, says: “Bacterial vaginosis doesn't usually cause problems during pregnancy, but there is a link between BV and some pregnancy complications.”

Research shows that bacterial vaginosis can lead to premature labour and birth if left untreated. It has also been linked to low birthweight, a problem associated with an increased risk of infant mortality, developmental problems in childhood, and poorer health in later life. Therefore, it's important to get checked out and treated if you notice any changes to your vagina during pregnancy.

Often, there are no symptoms of BV. Some women may notice a change in the normal secretions from the vagina.

"This discharge will usually be white or grey, thin or watery and have a strong, unpleasant fishy smell. You may also have itching, burning, or irritation in the vaginal area," says Vakharia.

It can be challenging to differentiate between normal changes in vaginal discharge during pregnancy and bacterial vaginosis. When you’re pregnant, it’s normal to have more discharge than you normally would. This helps to prevent any infections from travelling up the vagina and into the womb, protecting the baby. However, there are some key differences.

"Normal pregnancy discharge is usually thin, white, and odourless or has a mild, slightly sweet smell. It should not be accompanied by itching, burning, or unusual discomfort," says Vakharia.

If you think you have BV you should make an appointment with your doctor. Make sure you tell your doctor or nurse if you are pregnant, think you might be pregnant, or are breastfeeding.

More often than not, doctors will diagnose and treat based on the symptoms. Rarely, if the diagnosis is not clear, the doctor may carry out an examination to check your vagina and use a swab to collect a sample to test. This only takes a couple of minutes and may be slightly uncomfortable, but isn’t normally painful. Sometimes, a diagnosis can be made straight away using a piece of paper that changes colour depending on the pH - alkaline/acid balance - of your vagina.

Bacterial vaginosis is treated with antibiotics. An antibiotic cream or gel to use in the vagina may be given instead of antibiotic tablets by mouth.