Case 98: Vaginal discharge

 CASE 98: VAGINAL DISCHARGE

History

A 19-year-old woman presents with a vaginal discharge. She is currently 9 weeks pregnant 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 similar 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 cervical

smear test.

Examination

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.

Questions

• 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?100 Cases in Obstetrics and Gynaecology

284

ANSWER 98

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 sexual

history can be inaccurate). She has an ectropion, which can cause a clear discharge. A nonoffensive, 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.

Differential Diagnosis of Vaginal Discharge

• Infective

• sexually transmitted: trichomonas, chlamydia, gonorrhea

• non-sexually transmitted: candida, bacterial vaginosis

• Physiological

• pregnancy

• ovulation

• Cervical ectropion

Further investigation

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 >4.5. More formal criteria for diagnosis are the Amsel (discharge,

clue cells on microscopy, high pH and fishy odour with potassium hydroxide) or Hay/Ison

(relative lactobacilli to anaerobe proportions on Gram-stained vaginal smear) criteria.

Microbiological culture is not helpful as many of the anaerobes associated with BV are also

found as commensals.

Management

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.

BV and pregnancy

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.

KEY POINTS

• BV is a common cause of discharge and is the most likely diagnosis in a woman

complaining of an offensive or fishy odour, but a full sexually transmitted infection

screen is usually indicated to rule out other co-existing infection.

• Treatment with metronidazole is indicated in all affected pregnant women, but in

non-pregnant women it is only indicated for those with symptoms.