Complications of bacterial vaginosis 

For the vast majority of women, bacterial vaginosis (BV) is easily treated and doesn't cause any further problems. However, if the condition isn't treated, there's a small risk you may develop complications.

Pregnancy complications

There's some evidence to suggest untreated BV symptoms during pregnancy can increase your risk of pregnancy-related complications, particularly if you've had these problems in the past.

Pregnancy-related complications that have been associated with BV include:

  • premature birth – where the baby is born before the 37th week of pregnancy
  • miscarriage – the loss of pregnancy during the first 23 weeks
  • the amniotic sac breaking open too early – the amniotic sac is the bag of fluid where an unborn baby develops
  • chorioamnionitis – an infection of the chorion and amnion membranes (the membranes that make up the amniotic sac) and the amniotic fluid (the fluid that surrounds the foetus)
  • postpartum endometritis – infection and inflammation of the womb lining after giving birth, particularly after having a caesarean section

See your GP or visit a sexual health or genitourinary medicine (GUM) clinic as soon as possible if you're pregnant and have symptoms of BV. While your risk of developing these complications is small, treatment may reduce the risk.

If BV hasn't caused symptoms, there's no evidence to suggest it increases the risk of complications in pregnancy. Treatment might not be recommended if BV is detected while you're pregnant but don't have any symptoms.

Sexually transmitted infections

There's evidence that having BV can make you more at risk of catching sexually transmitted infections (STIs), such as chlamydia. This is possibly because the change in bacteria levels inside your vagina reduces your protection against infection.

Pelvic inflammatory disease

Although a link isn't entirely clear, some evidence suggests that BV may increase your risk of developing pelvic inflammatory disease (PID). PID causes infection and swelling of the upper female genital tract, including the womb, fallopian tubes and ovaries.

Symptoms of PID include:

  • pain around the pelvis or lower abdomen
  • discomfort or pain during sex felt deep inside the pelvis
  • bleeding between periods and after sex

If diagnosed at an early stage, PID can usually be treated successfully with a course of antibiotics. However, an estimated one in five women with the condition become infertile because of severe scarring on the fallopian tubes.

It's important to see your GP if you experience any symptoms of PID. Delaying treatment or having repeated episodes of PID can increase your risk of infertility.

In vitro fertilisation

Women who have BV and are using in vitro fertilisation (IVF) may have a lower success rate and an increased risk of early miscarriage.

If you're having IVF and have symptoms of BV, see your GP or speak to your infertility specialist.

Recurrent BV

It's relatively common for BV to recur after treatment with antibiotics. It's estimated that more than half the women treated for BV develop the condition again within three months.

If your BV returns, see your GP or sexual health or GUM clinic to discuss further treatment options.

Page last reviewed: 12/10/2015

Next review due: 01/10/2018