Irregular Vaginal Bleeding
Differential Diagnosis
Common Diagnoses
- Dysfunctional Uterine Bleeding
- Breakthrough Bleeding (BTB) on Contraceptive Pills and Long-Acting Reversible Contraception; also HRT
- Cervical Polyp or Erosion
- Post-Menopausal Atrophic Vaginitis
- Cervicitis
- Pelvic Inflammatory Disease
Occasional Diagnoses
- Endometrial Polyps
- Ovulatory Bleeding (Associated with Mittelschmerz)
- Perimenopause
- Ectopic Pregnancy
- Bleeding During Early Pregnancy (20% of all Pregnancies in First Trimester)
- Hyperthyroidism
- Hypothyroidism
- Miscarriage
Rare Diagnoses
- Uterine Bleeding in the Newborn
- Carcinoma (Ovary, Fallopian Tube, Uterus, Cervix and Vagina)
- Cystic Glandular Hyperplasia (Metropathia Haemorrhagica)
- Pyometra
- Hydatidiform Mole (5% Go on to Chorionic Carcinoma)
Ready Reckoner
Key distinguishing features of the most common diagnoses
| DUB | BTB | Polyp/Erosion | Cervicitis/PID | Atrophic Vaginitis | |
|---|---|---|---|---|---|
| Profuse Bleeding | Possible | No | No | Possible | No |
| Painful Periods | Possible | No | No | Yes | No |
| Discharge | No | No | Possible | Yes | Possible |
| Discomfort PV | No | No | No | Possible | Yes |
| Post-Coital Bleeding | No | No | Yes | Possible | Possible |
Possible Investigations
Likely:FBC, specialised gynaecological investigation (see the following list) for post-menopausal or intermenstrual bleeding
Possible:HVS and endocervical swab, colposcopy, transvaginal ultrasound
Small Print:TFT
- FBC to check for anaemia in heavy bleeding. Raised WCC in PID.
- TFT: To check for possible thyroid dysfunction
- HVS and endocervical swab: To attempt to establish pathogen in cervicitis and PID.
- Transvaginal ultrasound: To detect uterine and ovarian pathology, hydatidiform mole and to establish nature of problem in early pregnancy
- Colposcopy: If significant cervical pathology suspected
- Specialised gynaecological investigation (e.g. hysteroscopy and endometrial sampling): Performed in secondary care, particularly for intermenstrual and post-menopausal bleeding
Top Tips
- Try to distinguish between intermenstrual bleeding and irregular periods, as the likely causes are different (the former suggests a structural lesion, the latter is likely to be DUB). Simply asking the patient if the bleed feels like a period, with associated period-type symptoms, may help.
- Consider asking the patient to keep a menstrual diary. Very slight bleeding occurring consistently in mid-cycle with a slight pain and with no other worrying features suggests an ovulatory bleed.
- Remember that missed doses, diarrhoea and vomiting, and the first few months of treatment can cause breakthrough bleeding when using oral hormonal preparations. It is worth waiting a few more cycles before changing treatment.
Red Flags
- Post-menopausal bleeding is always abnormal. Even if atrophic vaginitis is present, do not assume this is the cause – this symptom requires a full assessment.
- A very inflamed-looking cervix with a purulent discharge is likely to be caused by Chlamydia infection – consider referral to the local GUM clinic for further investigation and contact tracing.
- A ‘recent’ normal cervical smear can provide false reassurance; if the cervix looks suspicious, do not take another smear – remember, this is a screening, rather than diagnostic, test. Instead, refer urgently for colposcopy.
- Beware of ‘breakthrough bleeding’ in patients on hormonal contraception or HRT. If it persists, consider other causes and investigate or refer.
- Unilateral pelvic pain with vaginal bleeding within a fortnight of a missed period suggests an ectopic pregnancy. Admit urgently