Early Pregnancy Bleeding: Navigating the First Trimester in the ED

First-trimester vaginal bleeding is one of the most common—and nerve-wracking—reasons patients come to the Emergency Department (ED). As emergency clinicians, we’re often the first stop. That means assessing and managing everything from the routine to the truly serious.

Here’s a practical guide to the most common causes of early pregnancy bleeding, how to manage them, and when to call in backup.

Threatened or Incomplete Miscarriage

This is the most frequent cause of first-trimester bleeding, showing up in up to 25% of pregnancies. Patients might have vaginal bleeding and cramping. On exam, the cervix could be slightly open, and ultrasound might reveal retained products of conception or a non-viable intrauterine pregnancy.

Management:

• Offer honest, compassionate counseling. Prepare the patient for the possibility of miscarriage.

• Arrange OBGYN follow-up.

• Expectant management usually works well, but surgical intervention (D&C) may be needed for heavy bleeding or retained products.

Call OBGYN if:

• Hemodynamic instability

• Bleeding is heavy and not improving

• Signs of infection or septic abortion (fever, pelvic pain, discharge)

• The pain is severe and needs more advanced pain management

Ectopic Pregnancy

Most ectopics happen in the fallopian tube and can be life-threatening. Patients often present with vaginal bleeding and unilateral abdominal pain.

Management:

• Get an ultrasound—fast.

• Ruptured ectopics need emergency surgery.

• Unruptured cases may be managed medically with methotrexate.

Call OBGYN if:

• You suspect an ectopic pregnancy

• Positive pregnancy test but no visible intrauterine pregnancy

• Hemodynamic instability

• Significant abdominal pain

Molar Pregnancy

Less common but important not to miss. Molar pregnancies involve abnormal placental development and can even lead to cancerous changes.

Management:

• Suspect molar pregnancy with heavy bleeding or very high hCG levels.

• Get a pelvic ultrasound.

• Refer to a gynecologic oncologist if diagnosed.

The “Grey Zone”: hCG and Ultrasound

When hCG levels are under 1,500 mIU/mL, don’t expect to reliably see an intrauterine pregnancy (IUP) on transvaginal ultrasound.

Key tips:

• Don’t get stuck “chasing an IUP” with serial hCGs and back-to-back ultrasounds in the ED.

• If the patient is stable and hCG is low, arrange outpatient OBGYN follow-up in 48–72 hours.

• Serial quantitative hCG testing 48 hours apart is the go-to for monitoring rise, fall, or plateau.

• Focus on clinical stability and risk stratification, not just imaging.

  Recommendation:

  • If the patient is stable with low hCG, provide clear discharge instructions and arrange for outpatient OBGYN follow-up within 48-72 hours.

  • If the patient is unstable or has concerning symptoms, prompt OBGYN consultation is required.

Common Ultrasound Findings

Subchorionic Hematoma/Hemorrhage

• Very common. Usually, it resolves on its own.

• Reassure the patient that many pregnancies with subchorionic hematomas proceed to term.

• Advise pelvic rest.

No Obvious Cause

• Sometimes, no clear cause is found.

• Reassure the patient and advise pelvic rest.

• Stress follow-up with OBGYN.

• Document everything.

Return Precautions

Advise patients to come back if they experience:

• Heavy bleeding (soaking a pad per hour)

• Severe abdominal pain

• Fever or chills

• Dizziness or lightheadedness

• Passing tissue

Take-Home Points

• First-trimester bleeding has a wide range of causes—don’t jump to conclusions.

• Ectopic pregnancies are critical to catch early.

• Avoid over-relying on serial ultrasounds in stable patients.

• Communicate clearly and compassionately. These are hard conversations.

• Know when to loop in OBGYN.

• Always give clear return precautions and ensure follow-up.