What should I do if I experience vaginal bleeding during pregnancy?

Management of Vaginal Bleeding During Pregnancy

If you experience vaginal bleeding during pregnancy, immediately seek medical evaluation with transvaginal ultrasound as the first-line diagnostic test, and critically, do not allow any digital pelvic examination until ultrasound has definitively excluded placenta previa, low-lying placenta, and vasa previa, as digital examination before imaging can precipitate catastrophic hemorrhage. 1, 2, 3

Immediate Actions and Critical Safety Measures

What You Must Do First

• Go to the emergency department or contact your obstetrician immediately for evaluation, as bleeding can represent conditions ranging from benign to life-threatening 1, 2, 3

• Refuse digital pelvic examination until after ultrasound imaging is completed, as this examination can cause catastrophic hemorrhage if placental abnormalities are present 1, 2, 3

• Expect your provider to assess your hemodynamic stability (blood pressure, heart rate) immediately upon arrival 1

Essential Diagnostic Tests

Transvaginal ultrasound is the primary and most important diagnostic tool for evaluating pregnancy-related bleeding at any gestational age, providing superior resolution compared to transabdominal ultrasound 1, 2, 3

Quantitative beta-hCG (pregnancy hormone) level must be obtained regardless of ultrasound findings, as this helps identify potential ectopic pregnancies and guides interpretation of imaging 1, 2, 3

Additional laboratory tests include:

• Rh factor status (to determine if you need RhoGAM) 4
• Hemoglobin level to assess blood loss 2
• Blood type and screen if significant bleeding is present 5

Management Based on Gestational Age and Findings

Very Early Pregnancy (3-5 Weeks)

At this early stage, the pregnancy may be too small to visualize reliably on ultrasound 3

If ultrasound shows "pregnancy of unknown location" (no visible pregnancy):

• Serial beta-hCG measurements every 48 hours are mandatory, as 7-20% of these cases will ultimately be ectopic pregnancies 1, 2, 3
• Repeat transvaginal ultrasound when beta-hCG reaches 1,500-2,000 mIU/mL (the discriminatory threshold), at which point a normal intrauterine pregnancy must show a gestational sac 2, 3
• In normal pregnancy, beta-hCG levels increase by 80% every 48 hours 6

If intrauterine pregnancy is confirmed:

• Ectopic pregnancy is essentially ruled out (except rare heterotopic pregnancy occurring in <1% of cases) 2, 3
• Follow-up ultrasound in 1-2 weeks to confirm fetal cardiac activity 2, 3

First Trimester (6-12 Weeks)

First trimester bleeding occurs in 7-27% of pregnancies, with approximately 50% resulting in miscarriage 3, 6

If viable intrauterine pregnancy with fetal cardiac activity is confirmed:

• Ectopic pregnancy is ruled out 1, 2
• Evaluation for subchorionic hemorrhage (blood collection between uterus and placenta) should be performed 1, 2
• Schedule follow-up ultrasound in 1-2 weeks to monitor fetal development 1, 2
• Guarded reassurance and watchful waiting are appropriate if you are medically stable 6

Important prognostic information:

• If pregnancy continues beyond first trimester bleeding, there is increased risk of preterm delivery, placental abruption later in pregnancy, and small for gestational age infants 2, 3

Second and Third Trimester (After 12 Weeks)

The most serious conditions to exclude immediately are:

• Placenta previa (placenta covering cervix) - affects 1 in 200 pregnancies at delivery 2, 5
• Placental abruption (placenta separating from uterus) - most common cause of serious vaginal bleeding, occurring in 1% of pregnancies 5
• Vasa previa (fetal blood vessels crossing cervix) - rare but can result in fetal death with rupture of membranes 5

Critical pitfall: Ultrasound misses up to 50% of placental abruptions, so maintain high clinical suspicion even with negative imaging 1, 2

Treatment Options for Early Pregnancy Loss

If early pregnancy loss (miscarriage) is diagnosed and you are hemodynamically stable, three management options exist 4, 6:

1. Expectant management (waiting for natural passage) - effective for many patients with incomplete abortion 6

2. Medical management with misoprostol - highly effective for early intrauterine pregnancy failure 6

3. Surgical management (dilation and curettage) - immediate option 4

Note: Progesterone supplementation for patients with early pregnancy bleeding and no history of miscarriage is likely of no benefit 4

Special Considerations for Ectopic Pregnancy

If ectopic pregnancy is diagnosed, management options include 4, 6:

• Surgical management via laparoscopy
• Medical management with methotrexate (for properly selected patients)
• Expectant management in certain circumstances

When Hemoglobin Drops

If your hemoglobin drops during bleeding (for example, from 107 g/L to 96 g/L):

• This suggests moderate blood loss but does not necessarily require transfusion 2
• Oral iron supplementation should be considered 2
• Transfusion is not indicated unless you are symptomatic or actively hemorrhaging 2
• Repeat complete blood count to monitor hemoglobin trajectory 2

Common Pitfalls to Avoid

Never allow digital pelvic examination before ultrasound - this cannot be emphasized enough, as it can cause life-threatening hemorrhage 1, 2, 3

Do not rely on a single ultrasound result - ultrasound can miss up to 74% of ectopic pregnancies initially, which is why serial beta-hCG monitoring is critical when initial ultrasound is non-diagnostic 2, 3

Avoid overinterpretation of early ultrasound findings that could lead to inappropriate treatment with methotrexate or surgery, potentially harming a normal early pregnancy 3

Ensure close follow-up - mandatory serial monitoring is essential for pregnancy of unknown location, as 7-20% will be ectopic pregnancies requiring intervention 1, 2, 3