Threatened Miscarriage
Condition
(Threatened Abortion; Threatened Pregnancy Loss)
Definition
Threatened miscarriage is bleeding from the vagina and symptoms that may mean a higher risk of miscarriage. It happens during the first trimester (13 weeks) of pregnancy. Not everyone who has bleeding in early pregnancy will miscarry.
Copyright © Nucleus Medical Media, Inc.

Causes
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 the risk of threatened miscarriage are:
- Infection
- Trauma
- Certain medicines
- Older age
Symptoms
The main symptom is bleeding during the first 13 weeks of pregnancy. Bleeding may be light or heavy. There may also be cramping.
Diagnosis
The doctor will ask about symptoms and past health. A physical exam will be done. Tests may be done to look for a cause. They may include:
- Ultrasound
- Fetal heart monitoring
- Blood tests
Ultrasound and blood tests may need to be done again after a week or two to check on the pregnancy.
Treatment
For many women, 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 women with Rh-negative blood. This can stop the body from making antibodies against the fetus' blood.
Prevention
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:
Health Canada
PregnancyInfo.ca—Society of Obstetricians and Gynaecologists of Canada
American Congress of Obstetricians and Gynecologists
American Pregnancy Association
CANADIAN RESOURCES:
Health Canada
PregnancyInfo.ca—Society of Obstetricians and Gynaecologists of Canada
References
- Bleeding during pregnancy. American Pregnancy Association website. Available at: http://americanpregnancy.org/pregnancy-complications/bleeding-during-pregnancy.
- Early pregnancy bleeding. EBSCO DynaMed website. Available at: https://www.dynamed.com/approach-to/early-pregnancy-bleeding.
- 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.
Contributors
- Beverly Siegal, MD, FACOG
(C) Copyright 2023 EBSCO Information Services
This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.
To send comments or feedback to our Editorial Team regarding the content please email us at healthlibrarysupport@ebsco.com.