Bacterial vaginosis is the commonest cause of vaginal discharge in women of reproductive age. It tends to cause an unpleasant thin discharge with a fishy odour, but may be symptomless. It is most common in sexually active women, those with a coil in, and those who douche regularly. When a woman has bacterial vaginosis, there is a change in the bacteria present in her vagina. Usually, the vast majority of bacteria in the vagina are lactobacilli. In bacterial vaginosis, these are greatly reduced and there is a consequent rise in the pH of the vagina and an increase in the growth of Gardnerella vaginalis and mixed anaerobes. The diagnosis of bacterial vaginosis is thought to be associated with an increased risk of second trimester miscarriage and preterm labour.
Metronidazole is the usual antibiotic used for treatment and is safe to use in pregnancy. Amoxycillin and erythromycin are also considered to be safe for use in pregnancy. The infection can, however, be difficult to eradicate. It might be necessary for your GP to refer you to a consultant regarding this, and they may want to do further swabs and tests. There are other antibiotics and vaginal creams that can be used for treatment of bacterial vaginosis, but some of these are not considered safe to use in pregnancy. With further test results and with the help of the hospital microbiologist, your consultant will be in a good position to make decisions about whether further treatment would be appropriate. The main risks to you and your baby are of preterm delivery so the further you get into your pregnancy, the less worrying the problem is.
It’s difficult to be sure of the cause of the pain that you have experienced or to predict whether it will become a problem during your pregnancy. A specialist would be able to advise you about this after examination and further investigation. Even if the infection continues, you will not need to have a caesarean. The infection is not thought to pose any threat to the baby during delivery. As the infection is often symptomless, it’s likely that many babies are born to mums with this infection, and no harm results.