A threatened abortion is vaginal bleeding that occurs in the first 20 weeks of pregnancy and is sometimes accompanied by abdominal cramps.

The condition is known as threatened abortion or threatened miscarriage because its symptoms indicate a miscarriage is possible.

Vaginal bleeding is fairly common among pregnant people. In a 2016 cohort, 24% of women experienced bleeding during the first 20 weeks of pregnancy. Of these women, 60% carried their pregnancy to term.

The exact cause of a threatened abortion usually isn’t known. But it’s more common among people who previously had a miscarriage.

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

During a regular miscarriage, people often experience 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 these symptoms.

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

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

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

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

Your doctor will 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 take only a few minutes to complete.

An ultrasound will monitor the heartbeat and development of the fetus. It can also 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 a pregnancy. Atypical levels of either hormone may indicate a problem.

A miscarriage often can’t be prevented. In some cases, though, 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. However, there is no research to back up these suggestions.

Your doctor will also treat conditions that increase the risk of complications during pregnancy, such as diabetes or hypothyroidism.

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

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

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

For some people, a threatened abortion is a very stressful experience and can lead to anxiety and depression. It’s important to talk with 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.

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

  • avoiding drinking alcohol
  • avoiding smoking cigarettes
  • not using illegal drugs
  • minimizing consumption of caffeine
  • avoiding certain foods that can make you ill and harm your fetus
  • 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 2 hours a 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.