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    1st Trimester Bleeding: Miscarriage – Diagnosis

    Obstetrics and Gynecology

    Last Updated Jul 23, 2020
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    • Early Pregnancy Loss (EPL): Intrauterine pregnancy (IUP) loss < 20 weeks Gestational Age (GA).
    • 80% occur in first 12 weeks GA.
    • 15-25% of all pregnancies.

    Differential Diagnosis for vaginal bleeding in context of IUP

    Diagnostic Process

    • Light bleeding or spotting in early pregnancy is common and does not increase risk of miscarriage.
    • Pain and heavy bleeding (similar or greater than normal menses) increases risk of miscarriage (adjusted OR 2.84, 95% CI 1.93–4.56).
    • With availability of US and β-hCG, pelvic exam is not required for diagnosis.
    • Speculum exam if: high suspicion of extrauterine bleeding source, or to remove any clots or tissue from cervical os if severe bleeding, cramping, and hypotension.
    •  Quantitative β-hCG, CBC, Group and Screen (assess if Rhogam needed).
    •  Consider:
      • Rhesus group – need Rhogam if Rh Negative:
        • MICRhoGAM [Rho(D) Immune Globulin (Human)] (50 µg) (250 IU), prefilled syringe 50 micrograms IM.
      • Urinalysis (UTI may trigger bleeding and/or EPL).
      • Cross-match if bleeding severe or hemodynamically unstable.
    • All symptomatic patients with a positive pregnancy test should have a pelvic US, irrespective of β-hCG level.
    • Initial assessment either with point-of-care ED ultrasound (POCUS) or diagnostic US by radiology.
    • Gold standard is transvaginal US (TVUS) – in ED if provider proficient in US use, otherwise by radiology.
    • Assess if IUP:
      • US indeterminate or uterus empty rule out ectopic pregnancy (see PECS – pregnancy of unknown location, PUL).
      • Viable pregnancy?


    * Serum progesterone: Consider if IUP of uncertain viability on U/S. Progesterone  < 15 nmol/L has a sensitivity of 75% and specificity of 98% in predicting nonviable pregnancy. An elevated serum progesterone is therefore reassuring for viability. This test may be beneficial if there is a need to determine viability at a single point in time. If a follow up U/S and/or β-hCG is possible, then the addition of a serum Progesterone does not change management in the ED.

    Follow up assessments with:

    Quality Of Evidence?


    Progesterone as a test to assess pregnancy viability. There is a theoretical benefit according to a meta-analysis by Verhaegen et al. (2010), however the benefit of this test has not yet been assessed in an ED context.

    • Obtain pelvic US on all pregnant patients irrespective of β-hCG.
    • Reliability of POCUS in ED to identify IUP, cardiac activity.
    • Deferral of pelvic exam when assessing threatened miscarriage.

    Relevant Clinical Resources

    1. EM Rounds Blog (St John’s Hospital) on early pregnancy and PUL.
    2. Emergency Medicine Cases blog and podcast on early pregnancy complications.
    3. Breaking Bad News.
    4. Communicating with Families Experiencing Pregnancy Loss.
    5. Criteria are from the Society of Radiologists in Ultrasound Multispecialty Consensus Conference on Early First Trimester Diagnosis of Miscarriage and Exclusion of a Viable Intrauterine Pregnancy, October 2012:


    Related Information

    Reference List

    1. Everett C. Incidence and outcome of bleeding before the 20th week of pregnancy: prospective study from general practice. BMJ. 1997;315(7099):32-34.

    2. American Society of Reproductive Medicine. Evaluation and treatment of recurrent pregnancy loss: a committee opinion. Fertil Steril. 2012;98(5):1103-1111.

    3. Dewey K, Voss K, Phillips C. Early Pregnancy Complications. In: Emergency Department Management of Obstetric Complications. Cham: Springer International Publishing; 2017:1-14.

    4. Hasan R, Baird DD, Herring AH, Olshan AF, Jonsson Funk ML, Hartmann KE. Association between first-trimester vaginal bleeding and miscarriage. Obstet Gynecol. 2009;114(4):860-867.

    5. Pontius E, Vieth JT. Complications in Early Pregnancy. Emerg Med Clin North Am. 2019;37(2):219-237.

    6. Isoardi K. Review article: The use of pelvic examination within the emergency department in the assessment of early pregnancy bleeding. Emerg Med Australas. 2009;21(6):440-448.

    7. Hahn SA, Promes SB, Brown MD, et al. Clinical Policy: Critical Issues in the Initial Evaluation and Management of Patients Presenting to the Emergency Department in Early Pregnancy. Ann Emerg Med. 2017;69(2):241-250.e20.

    8. Varner C, Balaban D, Borgundvaag B, McLeod S, Carver S. Fetal outcomes following emergency department point-of-care ultrasound for vaginal bleeding in early pregnancy. Can Fam Physician. 2016;62(7).

    9. Morin L, Cargill YM, Glanc P. Ultrasound Evaluation of First Trimester Complications of Pregnancy. J Obstet Gynaecol Canada. 2016;38(10):982-988.

    10. ACOG Practice Bulletin No. 200. Obstet Gynecol. 2018;132(5):e197-e207.

    11. Promes SB, Nobay F. Pitfalls in first-trimester bleeding. Emerg Med Clin North Am. 2010;28(1):219-234, x.

    12. Verhaegen J, Gallos ID, van Mello NM, et al. Accuracy of single progesterone test to predict early pregnancy outcome in women with pain or bleeding: meta-analysis of cohort studies. BMJ. 2012;345:e6077.

    Relevant Resources


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