A 19-year-old woman presents with a vaginal discharge. She is currently 9 weeks preg- nant in her first pregnancy. The discharge started about 3 weeks ago and is non-itchy and creamy in colour. It is not profuse but she feels it has a strong odour and is embarrassed about it. There is no bleeding or abdominal pain. She has had two or three previous sim- ilar episodes before the pregnancy that resolved spontaneously.
She has been with her partner for 3 years and neither of them have had any other sexual partners. They have always used condoms until 3 months ago. She has never had a cer- vical smear test.
The external genitalia appear normal. On speculum examination a small amount of smooth grey discharge is seen coating the vagina walls. There is a small cervical ectropion that is not bleeding.
· What is the likely diagnosis and the differential diagnosis?
· How would you further investigate and manage this patient?
· If your diagnosis is confirmed, what are the implications for the pregnancy?
The history suggests that the woman is not at risk of a sexually transmitted infection as a cause for her discharge (although this can never be ruled out entirely as the reported sex- ual history can be inaccurate). She has an ectropion, which can cause a clear discharge. A non-offensive, non-itchy discharge is normal in pregnancy.
The salient feature in this case is that the discharge has an offensive odour. Offensive odour is usually due to either trichomonas or bacterial vaginosis (BV). Trichomonas causes a profuse, sometimes frothy discharge with cervicitis, whereas BV causes a smooth, mild discharge, if any discharge at all.
The woman should have swabs taken for sexually transmitted infection as well as BV and candida.
A diagnosis of BV can be made, finding a typical thin grey discharge with a fishy odour and a vaginal pH of 6–7. More formal criteria for diagnosis are the Amsel (discharge, clue cells on microscopy, high pH and fishy odour with potassium hydroxide) or Hay/Ison cri- teria (relative lactobacilli to anaerobe proportions on Gram-stained vaginal smear). Microbiological culture is not helpful as many of the anaerobes associated with BV are also found as commensals.
Spontaneous onset and remission is typical with BV, and 50 per cent of women are asymptomatic. General advice should be given for avoiding BV including avoidance of vaginal douching, shower gel, and antiseptic agents or shampoo in the bath, as these interfere with the normal flora (lactobacilli) and allow an increase in BV organisms.
Specific treatment is with metronidazole for 5–7 days.
Late miscarriage, preterm birth, preterm premature rupture of membranes, and postpartum endometritis have all been associated with BV, and so any pregnant woman with BV should be treated with metronidazole. In contrast, non-pregnant women only require treatment if symptomatic.