Threatened Abortion

(Threatened Miscarriage; Threatened Pregnancy Loss)


Threatened abortion is a diagnosis that is made during the first 20 weeks of pregnancy. While some women have vaginal bleeding in the first 3 months of pregnancy, bleeding and symptoms that could suggest an increased risk of miscarriage are called threatened abortion.

Fetus in First Trimester

Nucleus image
Copyright © Nucleus Medical Media, Inc.

Causes    TOP

Early-pregnancy bleeding can originate from the uterus, cervix, vagina, or the external genital area.

In many cases, the cause of the bleeding is due to a minor condition that requires no treatment. If you have any vaginal bleeding during your pregnancy, especially if you also have abdominal pain, you should contact your doctor.

Possible causes of bleeding include:

  • Implantation of the embryo
  • Infection
  • Irritation, which may occur after intercourse
  • Miscarriage
  • The baby develops outside of the uterus—ectopic pregnancy
  • Molar pregnancy (rare growth inside the uterus)

Risk Factors    TOP

Factors that may increase your risk of threatened abortion include:

  • Infection
  • Trauma
  • Certain medications
  • Advanced maternal age

Symptoms    TOP

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

Diagnosis    TOP

Your doctor will ask about your symptoms and medical history. A physical exam will be done.

Tests that may be done include:

Treatment    TOP

Talk with your doctor about the best treatment plan for you. Many cases of threatened abortion require no treatment at all. In other cases, treatment options include:

Bed Rest

If you are bleeding heavily, your doctor may recommend bed rest. This has not shown to be beneficial, though. Your doctor may also want you to limit your activities.


Your doctor may prescribe progesterone . This is a female hormone that supports a pregnancy.

If your blood is Rh-negative and your partner's blood is Rh-positive, your doctor will give you an injection of Rho immune globulin. This will prevent your body from producing antibodies against your fetus' blood.

Prevention    TOP

While there is no clear way to prevent threatened abortion. To increase your chance of a healthy pregnancy:

  • Get regular prenatal care.
  • Avoid alcohol, cigarettes, and drugs.
  • Limit caffeine intake.
  • Control any long-term conditions that you may have , such as diabetes or a thyroid disorder.
  • Talk to your doctor before taking any medication. Some medications can be harmful to your baby.
  • Avoid contact with toxins.


American Congress of Obstetricians and Gynecologists
American Pregnancy Association


Canadian Association of Pregnancy Support Services


Bleeding during pregnancy. The American Congress of Obstetricians and Gynecologists website. Available at:
...(Click grey area to select URL)
Updated August 2011. Accessed October 8, 2015.
Bleeding during pregnancy. American Pregnancy Association website. Available at:
...(Click grey area to select URL)
Updated August 2015. Accessed October 8, 2015.
Last reviewed September 2015 by Andrea Chisholm, MD
Last Updated: 9/30/2013

EBSCO Information Services is fully accredited by URAC. URAC is an independent, nonprofit health care accrediting organization dedicated to promoting health care quality through accreditation, certification and commendation.

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 Our Health Library Support team will respond to your email request within 2 business days.