Vaginal bleeding in pregnancy (less than 20wks)

(Redirected from Miscarriage)


  • Occurs in 20-40% of 1st trimester pregnancies
  • Once IUP is confirmed by ultrasound no utility in obtaining B-hCG
  • US
    • Do not use hCG to determine whether ultrasound should be obtained

Abortion Types

Classification Characteristics OS Fetal Tissue Passage Misc
Threatened Abdominal pain or bleeding; < 20 weeks gestation Closed No If < 11 weeks (with fetal cardiac activity) 90% progress to term. If between 11 and 20 weeks 50% progress to term
Inevitable Abdominal pain or bleeding; < 20 weeks gestation Open No
Incomplete Abdominal pain or bleeding; < 20 weeks gestation Open Yes, some
Complete Abdominal pain or bleeding; < 20 weeks gestation Closed Yes, complete expulsion of products Distinguish from ectopic based on decreasing hCG and/or decreased bleeding
Missed Fetal death at <20 weeks without passage of any fetal tissue for 4 weeks after fetal death Closed No
Septic Infection of the uterus during a miscarriage. Most commonly caused by retained products of conception Open No, or may be incomplete Uterine tenderness and purulent discharge from the OS may be present

Clinical Features


  • Previous spontaneous abortion
  • Extent of bleeding, clots, tissue
    • Often quantified by pads per hour, greater than 1 per hour is concerning
  • Presence of cramping
  • Light-headedness? Chest pain? Shortness of breath? Palpitations?


  • Uterus able to palpated in abdomen ~ 12 weeks
  • Uterus able to visualzed by abdominal ultrasound ~ 10 weeks
  • Open os decreases, but does not rule-out, ectopic
  • If products of conception obtained send to pathology to rule-out trophoblastic disease
  • Can quantify amount of bleeding by number of scopettes of blood on pelvic exam
  • Large subchorionic hemorrhage increases chances of a miscarriage

Differential Diagnosis

Vaginal Bleeding in Pregnancy (<20wks)




  • By ultrasound finding:
    • +IUP = threatened abortion
      • Ectopic ruled-out unless on fertility drugs
    • Empty uterus + free fluid/adnexal mass = Ectopic
    • Empty uterus + no free fluid / no mass
      • Beta-HCG:
        • >1,500 = Presumed ectopic
        • <1,500 = Indeterminate: follow serial B-HCG levels in 48hrs (if no peritonitis)
          • Increased >66% = normal IUP
          • Increased <66% = Ectopic

Discrimatory Zone[1]

Values are for IUP visualization, not ectopic visualization

  • Pelvic Ultrasound: hCG >1500
  • Abd Ultrasound: hCG >3000[2]


  1. RhoGAM if Rh Negative
  2. Assess need for transfusion (severe anemia or hypotension)
  3. Treat specific process:


  • Admit for:
    • Ectopic
    • Life threatening bleeding
    • Surgical abdomen

See Also

Vaginal bleeding (main)


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  1. Ankum WM, Van der Veen F, Hamerlynck JV, Lammes FB. Suspected ectopic pregnancy. What to do when human chorionic gonadotropin levels are below the discriminatory zone. J Reprod Med. 1995;40:525–8
  2. Wag, R. et al. Use of a !-hCG Discriminatory Zone With Bedside Pelvic Ultrasonography. Annals of Emergency Medicine. 58(1)12-20. PDF