Intermenstrual Bleeding (Spotting Between Periods): Causes & When to See a Doctor

Intermenstrual bleeding (metrorrhagia) = uterine bleeding between expected menstrual periods. Common but not always benign.

Common Causes

1. Hormonal fluctuation: Adolescence, perimenopause, anovulatory cycles
2. Hormonal contraception: Breakthrough bleeding (first 3–6 months of OCPs, IUD, implant, injection)
3. Ovulation spotting: Mid-cycle; brief, light; estrogen dip
4. Implantation bleeding: ~6–12 DPO; light, brief; possible pregnancy sign
5. Cervical/endometrial pathology: Polyps, fibroids, hyperplasia, cancer
6. STIs: Chlamydia, gonorrhea, trichomonas — cervicitis
7. PCOS: Chronic anovulation → irregular shedding
8. Medications: Anticoagulants, antipsychotics, some herbal supplements
9. Systemic: Thyroid dysfunction, coagulopathy, liver disease
10. Trauma: Intercourse, foreign body, exam

Red Flags (Urgent Evaluation)

• Heavy bleeding (soaking pad/hr)
• Postcoital bleeding (recurrent)
• Postmenopausal bleeding (always investigate)
• Pain, fever, foul discharge
• Pregnancy + bleeding
• Age >45 with new irregular bleeding

Diagnostic Approach

• Pregnancy test (always first)
• CBC, TSH, coagulation if heavy
• Pelvic exam, STI testing
• Transvaginal ultrasound (endometrial thickness, structural lesions)
• Endometrial biopsy (age >45 or risk factors)
• Hysteroscopy if ultrasound abnormal

Track bleeding pattern (dates, heaviness, associated symptoms) for your provider.