What causes postcoital (after sex) bleeding?

Postcoital Bleeding: Causes and Evaluation

Postcoital bleeding is most commonly caused by cervicitis (often from sexually transmitted infections like Chlamydia trachomatis or Neisseria gonorrhoeae), cervical polyps, cervical ectropion, or vaginal trauma, though cervical cancer must be excluded through direct visualization with speculum examination. 1, 2

Primary Etiologies

Infectious Causes

• Cervicitis from STIs is the leading cause in women under 25 years or those with new/multiple sexual partners, with C. trachomatis and N. gonorrhoeae being the most common pathogens 1, 2
• Mucopurulent cervicitis presents with purulent endocervical discharge and easily induced cervical bleeding during examination 1
• Women with cervicitis often have asymptomatic infection but may report abnormal vaginal discharge 1

Structural Cervical Causes

• Cervical polyps account for approximately 5% of postcoital bleeding cases and are typically benign 3
• Cervical ectropion (columnar epithelium on the ectocervix) causes fragile tissue that bleeds easily with contact 1
• Cervical intraepithelial neoplasia (CIN) is found in approximately 17% of women presenting with postcoital bleeding 3

Malignancy

• Cervical cancer is the most serious cause, occurring in approximately 4% of women with postcoital bleeding 3
• The probability ranges from 1 in 44,000 for women aged 20-24 to 1 in 2,400 for women aged 45-54 2
• Importantly, 30% of women with significant cervical pathology (including cancer) have normal or inflammatory Pap smears 3

Traumatic Causes

• Vaginal lacerations, particularly involving the posterior fornix, occur most commonly in nulliparous women 4
• Hymenal tears account for approximately 39% of traumatic postcoital bleeding cases 4

Diagnostic Approach

Mandatory Initial Steps

• Perform speculum examination immediately to visualize the cervix and vagina, assessing for cervicitis, lesions, polyps, ectropion, or trauma 2
• Any visible ulcerating or fungating cervical lesion mandates urgent referral for suspected malignancy 2

Laboratory Testing

• Obtain NAAT testing for C. trachomatis and N. gonorrhoeae on cervical or urine specimens 2
• Perform wet mount examination to assess for >10 WBCs per high-power field (suggests cervicitis) and evaluate for Trichomonas vaginalis or bacterial vaginosis 2

Critical Pitfalls to Avoid

• Do NOT perform unscheduled Pap smears as part of postcoital bleeding evaluation—they are not recommended outside regular screening programs and delay appropriate management 2
• Do NOT rely on negative cervical cytology to exclude serious pathology, as 0.6% of women with postcoital bleeding, normal-appearing cervix, and normal smear still have invasive cervical cancer 3
• Do NOT skip speculum examination—all women require direct visualization to avoid missing frank cervical cancer 2

Treatment Algorithm

For High-Risk Women (Age <25 or New/Multiple Partners)

• Initiate presumptive treatment for cervicitis with Azithromycin 1 g orally as a single dose OR Doxycycline 100 mg orally twice daily for 7 days 2
• Treat sexual partners to prevent reinfection 2
• Instruct patients to abstain from sexual intercourse until therapy is completed 1

For Identified Structural Lesions

• Cervical polyps typically require removal 3
• Cervical ectropion may be managed conservatively or with ablative therapy if symptomatic 1
• Vaginal lacerations require surgical suture in 97% of cases, with sexual abstinence for at least two weeks 4

For Persistent Bleeding with Normal Examination

• Refer to gynecology for colposcopy, as cervical intraepithelial neoplasia or early-stage cancer may only be visible with colposcopic magnification 3
• Approximately 49% of women with postcoital bleeding have no identifiable cause on initial evaluation 3

For Suspected Malignancy

• Do NOT delay referral when malignancy is suspected based on examination findings 2
• Urgent gynecologic oncology consultation is required for any suspicious cervical lesion 2

Special Considerations

Partner Management

• All sex partners within the preceding 60 days should be referred for evaluation and treatment when STIs are identified or suspected 1
• Partner notification and treatment is essential to prevent reinfection 2

Persistent or Recurrent Cases

• If symptoms persist after treatment and reinfection is excluded, additional antimicrobial therapy may be of minimal benefit 1
• Consider non-microbiologic determinants such as inflammation in cervical ectropion 1