by McCoy K
(Threatened Abortion; Threatened Pregnancy Loss)


Threatened miscarriage is bleeding from the vagina and symptoms that may mean a higher risk of miscarriage. It happens during the first 3 months (or 20 weeks) of pregnancy. Not everyone who has bleeding in early pregnancy will miscarry.

Fetus in First Trimester
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Possible causes of bleeding include:

  • Embryo is implanting
  • Infection
  • Irritation that may occur after sex
  • Miscarriage
  • The baby grows outside the uterus—ectopic pregnancy
  • Molar pregnancy—a rare growth in the uterus

Risk Factors

Things that may increase a person's risk include:

  • Infection
  • Trauma
  • Some medicines
  • Older age


The main symptom is bleeding during the first 20 weeks of pregnancy. Bleeding may be light or heavy. There may also be cramping.

Tell your doctor if you have bleeding from the vagina any time during your pregnancy.


The doctor will ask about your symptoms and past health. A physical exam will be done. Tests may be done to look for a cause. They may include:

Ultrasound and blood tests may need to be done again after a week or two to check on the pregnancy.


For many people, no treatment is needed. If needed, treatment may include:

  • Medicine to treat some causes. This may include progesterone, a hormone that supports a pregnancy.
  • Rho immune globulin for mothers with Rh-negative blood. This can stop the body from making antibodies against the fetus' blood.


It is not always possible to prevent threatened miscarriage. Prenatal care may help find and treat problems early.


American Congress of Obstetricians and Gynecologists 

American Pregnancy Association 

CANADIAN RESOURCES—Society of Obstetricians and Gynaecologists of Canada 

Health Canada 


Bleeding during pregnancy. American Pregnancy Association website. Available at: Accessed March 23, 2022.

Early pregnancy bleeding. EBSCO DynaMed website. Available at: Accessed March 23, 2022.

Hendriks, E., MacNaughton, H., et al. First trimester bleeding: evaluation and management. American Family Physician, 2019; 99(3): 166-174.

Wahabi, H.A., Fayed, A.A., et al. Progestogen for treating threatened miscarriage. Cochrane Database Syst Rev, 2018; 8: CD005943.

Revision Information

  • Reviewer: EBSCO Medical Review Board Mary-Beth Seymour, RN
  • Review Date: 03/2022
  • Update Date: 03/23/2022