What is the approach to assessing vaginal bleeding?

Approach to Assessing Vaginal Bleeding

The assessment of vaginal bleeding must begin with determining pregnancy status and hemodynamic stability, followed by ultrasound imaging before any digital pelvic examination in pregnant patients to avoid catastrophic hemorrhage from placental abnormalities. 1, 2

Initial Assessment

Immediate Priorities

• Assess hemodynamic stability first to determine if acute stabilization is needed 3
• Determine pregnancy status immediately through urine or serum beta-hCG testing, as this fundamentally changes the diagnostic approach 2
• Obtain quantitative beta-hCG level regardless of ultrasound findings in pregnant patients 2

Critical Safety Rule for Pregnant Patients

• Digital pelvic examination must be avoided until ultrasound excludes placenta previa, low-lying placenta, and vasa previa in second and third trimester bleeding, as examination before imaging can precipitate catastrophic hemorrhage 1, 2

Differential Diagnosis by Patient Population

Pregnant Patients - First Trimester

• Early intrauterine pregnancy (80-93% of pregnancy of unknown location cases) 2
• Ectopic pregnancy (7-20% of pregnancy of unknown location cases) 2
• Miscarriage 1
• Subchorionic hemorrhage 2

Pregnant Patients - Second and Third Trimester

• No identifiable reason (approximately 50% of cases) 1
• Placenta previa (most common diagnosis made) 1
• Placental abruption (affects approximately 1% of pregnancies) 1
• Vasa previa 1
• Preterm labor with cervical bleeding 1
• Uterine rupture 1
• Cervicitis or cervical polyp 1
• Vaginal laceration 1
• Normal "bloody show" preceding labor 1

Non-Pregnant Reproductive Age Women

• Dysfunctional uterine bleeding (most common in postmenarchal adolescents) 4
• Hematologic disorders 4
• Infections 4
• Structural uterine pathology 3

Prepubertal Girls

• Foreign body 5
• Sexual abuse 5, 6
• Malignancy (rhabdomyosarcoma) 5, 4
• Benign causes (most common) 5

History Taking

Menstrual History

• Document menstrual cycle pattern, duration, and volume to characterize the bleeding 3
• Determine if bleeding is truly vaginal versus urinary tract, anal, or skin bleeding 6

Bleeding History

• Obtain personal and family bleeding history to assess for coagulopathies 3
• Assess for symptoms of anemia or hemodynamic compromise 3

Pregnancy-Related History

• In pregnant patients with second/third trimester bleeding, evaluate for miscarriage or preterm labor symptoms through history and physical examination 1

Pediatric Considerations

• Always consider sexual abuse in prepubertal vaginal bleeding and ensure safety of the patient 5, 6
• Determine if bleeding source is confirmed vaginal versus other sites 6

Physical Examination

Pregnant Patients - Critical Sequence

1. Perform ultrasound FIRST before any digital examination in second and third trimester bleeding 1, 2
2. Speculum examination to assess for cervical lesions, polyps, or inflammation after placental abnormalities are excluded 2
3. Evaluate uterine contractions or increased tone in pregnancy-related bleeding 2
4. In postpartum patients, perform bimanual examination to evaluate uterine tone and size and assess for retained products of conception, uterine atony, or lacerations 2

Non-Pregnant Patients

• Perform speculum examination to visualize cervix and vagina for structural lesions 7
• Bimanual examination to assess uterine size and adnexal masses 7

Prepubertal Patients

• Recognition of normal female prepubertal anatomy is essential to detect abnormalities 6
• If child is reluctant to undergo examination or extent of injury cannot be determined, examination under anesthesia with vaginoscopy is recommended 5
• Vaginoscopy allows clear visualization without distorting hymenal anatomy and permits diagnosis/removal of foreign bodies 5
• In cases of suspected sexual abuse, providers specifically trained in pediatrics must be present 5

Investigations

Pregnant Patients - First Trimester

• Transvaginal ultrasound is the primary diagnostic tool, providing better resolution than transabdominal ultrasound 2
• Quantitative beta-hCG level 2
• If intrauterine pregnancy is confirmed, ectopic pregnancy is essentially ruled out (except rare heterotopic pregnancy) 2
• For pregnancy of unknown location, obtain serial beta-hCG measurements 48 hours apart 2
• Repeat ultrasound when beta-hCG reaches 1,500-2,000 mIU/mL (discriminatory threshold), at which point a normal intrauterine pregnancy must show a gestational sac 2

Pregnant Patients - Second and Third Trimester

• Transabdominal and transvaginal ultrasound with Doppler are usually appropriate 2
• Ultrasound is the mainstay for making accurate diagnoses and emergent guidance of management 1
• Note that ultrasound may miss up to 50% of placental abruptions, so clinical correlation is essential 2
• Central abruption is associated with worse perinatal outcome than marginal placental separation 1

Non-Pregnant Patients

• Laboratory studies including complete blood count, coagulation studies 3
• Imaging studies as indicated 3

Empiric Treatment

Acute Stabilization

• Focus on hemodynamic stabilization in heavy bleeding 3
• Resuscitation with intravenous fluids and blood products as needed 3

Pregnancy-Specific Management

• For subchorionic hemorrhage with viable pregnancy, schedule follow-up ultrasound in 1-2 weeks 2
• For pregnancy of unknown location, continue serial beta-hCG measurements until diagnosis is established 2
• For continuing pregnancies, schedule follow-up ultrasound in 1-2 weeks 2
• Second and third trimester pathologic bleeding may require hospitalization and/or delivery 1

Long-Term Treatment

• Medical and surgical modalities based on underlying etiology 3

Indications for Referral

Immediate Specialist Consultation

• Hemodynamically unstable patients requiring acute intervention 3
• Confirmed or suspected ectopic pregnancy 2
• Second/third trimester bleeding with placenta previa, vasa previa, placental abruption, or uterine rupture 1

Pediatric Specialist Referral

• Prepubertal vaginal bleeding always requires comprehensive assessment 6
• Suspected sexual abuse requires forensic medical examiner or specialist pediatrician 5, 6
• Need for examination under anesthesia with vaginoscopy 5
• Suspected malignancy 5, 4

Gynecology Referral

• Pregnancy of unknown location requiring serial monitoring 2
• Heavy vaginal bleeding requiring long-term management 3
• Structural abnormalities requiring surgical intervention 3

Common Pitfalls

• Never perform digital pelvic examination before ultrasound in pregnant patients with second/third trimester bleeding - this can cause catastrophic hemorrhage with placenta previa or vasa previa 1, 2
• Ultrasound misses up to 50% of placental abruptions and 74% of ectopic pregnancies initially - serial beta-hCG monitoring is critical when initial ultrasound is non-diagnostic 2
• Do not assume all prepubertal vaginal bleeding is benign - always consider sexual abuse and malignancy 5, 6
• In pregnancy of unknown location, approximately 7-20% will be ectopic pregnancies - close follow-up with serial beta-hCG is mandatory 2