What does it mean if I'm pregnant and experiencing dark blood with minor cramps?

Dark Vaginal Bleeding with Minor Cramping in Pregnancy

You need immediate evaluation with transvaginal ultrasound and quantitative beta-hCG to determine if this represents a viable intrauterine pregnancy, early pregnancy loss, or ectopic pregnancy—dark blood with cramping suggests possible threatened abortion or early pregnancy loss, but ectopic pregnancy must be ruled out urgently. 1, 2

Immediate Clinical Significance

Dark blood typically indicates older blood that has taken time to exit the uterus, which can occur in several pregnancy-related conditions 3, 4:

• Threatened abortion (bleeding with viable pregnancy still present) occurs in 20-40% of pregnant women in the first trimester 3, 5
• Early pregnancy loss (miscarriage in progress or completed)
• Ectopic pregnancy (life-threatening condition requiring urgent diagnosis) 1
• Subchorionic hemorrhage (bleeding between uterine wall and gestational sac) 2

The combination of bleeding and cramping increases the risk of early pregnancy loss compared to bleeding alone 4.

Critical First Steps

Do NOT perform digital pelvic examination until ultrasound is completed

Avoid digital vaginal examination before imaging, as this can precipitate catastrophic hemorrhage if placenta previa or vasa previa is present 2. Visual speculum examination to assess for cervical lesions, polyps, or active bleeding source is appropriate 2.

Obtain transvaginal ultrasound immediately

Transvaginal ultrasound is the primary diagnostic tool and provides superior resolution for early pregnancy evaluation compared to transabdominal approach 2. The ultrasound will determine:

• Intrauterine pregnancy (IUP) present: If confirmed, ectopic pregnancy is essentially ruled out (except rare heterotopic pregnancy in <1% of spontaneous conceptions) 1
• Pregnancy of unknown location (PUL): No IUP visible and no ectopic pregnancy identified—occurs when pregnancy is very early (<4.5-5 weeks) or represents early loss 1
• Ectopic pregnancy: Extraovarian mass, free fluid with echoes (blood), or tubal ring sign 1

Obtain quantitative beta-hCG level

Measure beta-hCG regardless of ultrasound findings 2. The discriminatory threshold is 1,500-2,000 mIU/mL, above which a normal IUP must show a gestational sac on transvaginal ultrasound 2, 4.

Management Based on Findings

If Viable Intrauterine Pregnancy Confirmed

• Diagnosis: Threatened abortion with viable pregnancy 4
• Management: Expectant management with reassurance 4
• Follow-up ultrasound: Schedule repeat imaging in 1-2 weeks to confirm continued viability 2
• Activity: Bed rest does not improve outcomes and is not recommended 4
• Progesterone: Insufficient evidence to support routine use in women without history of recurrent miscarriage 5, 4

If Pregnancy of Unknown Location

Most PULs (80-93%) will be early intrauterine pregnancies or failed intrauterine pregnancies, but 7-20% will later be diagnosed as ectopic pregnancies 2. This requires close surveillance:

• Serial beta-hCG measurements every 48 hours 2
• Repeat ultrasound when beta-hCG reaches discriminatory threshold of 1,500-2,000 mIU/mL 2, 4
• Continue monitoring until definitive diagnosis established 2

If Early Pregnancy Loss Diagnosed

Ultrasound criteria for definitive diagnosis include 4:

• Mean gestational sac diameter ≥25 mm with no embryo
• Crown-rump length ≥7 mm with no fetal cardiac activity

Treatment options (all equally acceptable if hemodynamically stable) 5, 4:

• Expectant management: Allow natural passage
• Medical management: Mifepristone and misoprostol
• Surgical management: Uterine aspiration

If Ectopic Pregnancy Suspected or Confirmed

Ectopic pregnancy accounts for 6% of all maternal deaths and requires urgent intervention 4. Key ultrasound findings include 1:

• Extraovarian mass (tubal ring or heterogeneous mass)
• Free fluid with echoes (blood) in pelvis
• No intrauterine pregnancy with beta-hCG above discriminatory threshold

Important caveat: Ultrasound initially misses up to 74% of ectopic pregnancies, which is why serial beta-hCG monitoring is critical when initial ultrasound is non-diagnostic 2.

Common Pitfalls to Avoid

• Never diagnose ectopic pregnancy based solely on absence of IUP—positive findings (extraovarian mass, free fluid with echoes) are required to avoid inappropriate methotrexate or surgical treatment 1
• Do not rely on single beta-hCG value—trends over 48 hours provide more useful information than isolated measurements 4
• Do not assume dark blood is benign—color of blood does not reliably predict outcome; ectopic pregnancy must still be excluded 3
• Check Rh status immediately—Rh-negative women require RhoGAM administration to prevent alloimmunization 5

When to Seek Emergency Care Immediately

Seek emergency evaluation if you develop 1, 4:

• Heavy bleeding (soaking through pad in <1 hour)
• Severe abdominal pain
• Shoulder pain (suggests intraperitoneal bleeding)
• Dizziness, lightheadedness, or syncope
• Fever or chills