Threatened Abortion (Threatened Miscarriage)
Threatened abortion refers to vaginal bleeding during the first 20 weeks of pregnancy. Learn about its symptoms, risk factors, and diagnosis.

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What Is a Threatened Abortion?

A threatened abortion is vaginal bleeding that occurs in the first 20 weeks of pregnancy. The bleeding is sometimes accompanied by abdominal cramps. These symptoms indicate that a miscarriage is possible, which is why the condition is known as a threatened abortion or threatened miscarriage.

Vaginal bleeding is fairly common among pregnant women. About 20 to 30 percent of women will experience bleeding during the first 20 weeks of pregnancy. Approximately 50 percent of these women will carry their baby to term.

The exact cause of a threatened abortion usually isn’t known. However, it’s more common among women who have previously had a miscarriage.

What Are the Symptoms of a Threatened Abortion?

Any vaginal bleeding during the first 20 weeks of pregnancy can be a symptom of a threatened abortion. Some women also have abdominal cramps or lower back pain.

During an actual miscarriage, women often experience either a dull or sharp pain in the abdomen and lower back. They may also pass tissue with clot-like material from the vagina.

Call your doctor or obstetrician immediately if you’re pregnant and experiencing any of these symptoms.

Who Is at Risk for a Threatened Abortion?

The actual cause of a threatened abortion isn’t always known. However, there are certain factors that may increase your risk of having one. These include:

  • a bacterial or viral infection during pregnancy
  • trauma to the abdomen
  • advanced maternal age (over age 35)
  • exposure to certain medications or chemicals

Other risk factors for a threatened abortion include obesity and uncontrolled diabetes. If you’re overweight or have diabetes, speak with your doctor about ways to stay healthy during pregnancy.

You should also tell your doctor about any medications or supplements you’re taking. Some may be unsafe to use during pregnancy.

How Is a Threatened Abortion Diagnosed?

Your doctor may perform a pelvic exam if a threatened abortion is suspected. During a pelvic exam, your doctor will examine your reproductive organs, including your vagina, cervix, and uterus. They’ll look for the source of your bleeding and determine whether the amniotic sac has ruptured. The pelvic exam will only take a few minutes to complete.

An ultrasound will be done to monitor the heartbeat and development of the fetus. It can also be done to help determine the amount of bleeding. A transvaginal ultrasound, or an ultrasound that uses a vaginal probe, is typically more accurate than an abdominal ultrasound in early pregnancy. During a transvaginal ultrasound, your doctor will insert an ultrasound probe about 2 or 3 inches into your vagina. The probe uses high-frequency sound waves to create images of your reproductive organs, allowing your doctor to see them in more detail.

Blood tests, including a complete blood count, may also be performed to check for abnormal hormone levels. Specifically, these tests will measure the levels of hormones in your blood called human chorionic gonadotropin (HCG) and progesterone. HCG is a hormone that your body produces during pregnancy, and progesterone is a hormone that supports pregnancy. Abnormal levels of either hormone may indicate a problem.

How Is a Threatened Abortion Treated?

A miscarriage often can’t be prevented. In some cases, however, your doctor may suggest ways to lower your risk of having a miscarriage.

As you recover, your doctor may tell you to avoid certain activities. Bed rest and avoiding sexual intercourse may be suggested until your symptoms go away. Your doctor will also treat any conditions known to increase the risk of complications during pregnancy, such as diabetes or hypothyroidism.

Your doctor may also want to give you an injection of progesterone to increase levels of the hormone. Your doctor will also administer Rh immunoglobulin if you have Rh-negative blood and your developing baby has Rh-positive blood. This stops your body from creating antibodies against your child’s blood.

What Is the Long-Term Outlook?

Many women who experience a threatened abortion go on to deliver healthy babies. This is more likely if your cervix isn’t already dilated and if the fetus is still securely attached to the wall of your uterus. If you have abnormal hormone levels, hormone therapy can often help you carry the baby to term.

Approximately 50 percent of women who experience a threatened abortion don’t have a miscarriage. Most women who do miscarry will go on to have successful pregnancies in the future. However, you should see your doctor to discuss possible causes if you’ve experienced two or more miscarriages in a row.

For some women, a threatened abortion is a very stressful experience and can lead to anxiety and depression. It’s important to talk to your doctor if you’re experiencing symptoms of either condition following a threatened abortion or miscarriage. They can help you get the treatment you need. Your doctor may also know about local support groups where you can discuss your experience and concerns with others who can relate to what you’re experiencing.

How to Maintain a Healthy Pregnancy

It’s difficult to prevent a miscarriage, but certain behaviors can help support a healthy pregnancy. These include:

  • not drinking alcohol
  • not smoking cigarettes
  • not using illegal drugs
  • minimizing consumption of caffeine
  • avoiding certain foods that can make you ill and harm your baby
  • avoiding exposure to toxic chemicals or harsh cleaning solutions
  • promptly treating any viral or bacterial infections that occur
  • taking prenatal vitamins, such as folic acid
  • exercising at least two hours per week

You can also maintain a healthy pregnancy by getting early, comprehensive prenatal care. Receiving prompt prenatal care makes it possible for your doctor to detect and treat any potential health problems early in the pregnancy. This will prevent complications and help ensure the delivery of a healthy baby. 

Written by: Jaime Herndon and Lauren Reed-Guy
Edited by:
Medically Reviewed by: [Ljava.lang.Object;@76bc2c7a
Published: Jun 26, 2012
Published By: Healthline Networks, Inc.
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