Merck Manual

Please confirm that you are not located inside the Russian Federation

honeypot link
Quick Facts



The Manual's Editorial Staff

Last full review/revision Jun 2021| Content last modified Jun 2021
Click here for the Professional Version
Get the full details

What is a miscarriage?

Miscarriage is when you lose your baby before 20 weeks of pregnancy. Most miscarriages happen in the first 12 weeks of pregnancy.

  • Bleeding and cramping are common signs of miscarriage

  • If you were pregnant and didn't know it yet, you can have a miscarriage and think it was just your period

  • To tell if you’ve had a miscarriage, doctors will check your cervix (the lower part of your uterus)

  • Doctors will also do an ultrasound (moving pictures of the insides of your uterus, also called your womb)

  • Many women who’ve had one miscarriage get pregnant again and deliver healthy babies

  • However, your chances of miscarriage go up each time: the more miscarriages you have, the more likely you are to have another one

  • If you’ve had several miscarriages, you may want to see a doctor before you get pregnant again

  • Doctors can try to make your next pregnancy more successful

What causes a miscarriage?

Doctors don't always know what causes you to miscarry. Miscarriage is not caused by a sudden emotional shock, such as getting bad news. Also, minor injuries like slipping and falling do not cause miscarriage. However, major injuries like a bad car crash can cause miscarriage.

Causes in the first 12 weeks of pregnancy

  • A problem with your baby, such as a birth defect or an inherited disorder

Sometimes the baby has a defect that is so severe that the baby (fetus) can't live more than a month or two inside you. A severe defect causes most miscarriages in the first 12 weeks of pregnancy.

Causes in weeks 13 through 20 of pregnancy

Often, doctors never figure out the cause of miscarriage at this stage. But sometimes they can pinpoint one of these as the cause:

Causes of repeated miscarriages

If you have had several miscarriages, doctors will look for problems such as:

  • Blood that clots too easily in the woman

  • Abnormal chromosomes in the baby from either parent

What are the symptoms of a miscarriage?

A miscarriage early in pregnancy may just seem like a normal period. If you didn't know you were pregnant, you probably wouldn't think you were having a miscarriage.

Other times there are obvious symptoms:

  • Bright or dark red blood

  • Cramping

  • Passing large clots and bits of tissue

At first you may have only a small amount of bleeding, similar to having your period. As the miscarriage continues, the bleeding usually gets worse. The blood may be bright or dark red. Sometimes you'll also pass blood clots. You'll have cramps that may get worse as your uterus (womb) pushes out bits and pieces of the pregnancy.

Call your doctor right away if you have any bleeding during your pregnancy. Not all bleeding during pregnancy means you're having a miscarriage. About half the time, the pregnancy continues just fine. However, your doctor needs to check to see whether you had a miscarriage or not. If you pass large clots or bits of tissue, put them in a container or wrap them in a towel for the doctor to look at.

How can doctors tell if I've had a miscarriage?

If you've had bleeding or cramping during the first 20 weeks of your pregnancy, doctors will:

  • Do a pelvic exam: They look inside your vagina (birth canal) to check your cervix (the lower part of your uterus where your baby comes out)—if your cervix is open, a miscarriage is likely

  • Do an ultrasound: This test uses sound waves to create moving pictures of the inside of your uterus—it can show if your baby is still alive

  • Do blood tests: Doctors check your levels of the pregnancy hormone hCG

How do doctors treat a miscarriage?

If the fetus and the placenta (the organ that feeds your unborn baby) are no longer in your body, you won't need any treatment. The bleeding and cramps will stop soon.

If bits and pieces of the pregnancy are still in your body, doctors might:

  • Watch to see if your uterus will empty itself, as long as you don’t have a fever or seem sick

  • Do a procedure to remove the rest of the pregnancy

If doctors need to remove pieces of your pregnancy from your uterus, they'll give you medicine to make you sleepy. The procedure you have depends on how far along the pregnancy is:

  • In the first 12 weeks of pregnancy: Remove pieces using a suction instrument put into your uterus through your vagina

  • Between 12 and 20 weeks of pregnancy: Remove pieces using surgical instruments put into your uterus through your vagina

  • If close to 20 weeks of pregnancy: You may be given a medicine to start labor to pass the rest of the pregnancy

How can I prevent a miscarriage?

You can't really prevent a miscarriage. If you've had some bleeding or cramping during the first 20 weeks of your pregnancy, your doctor may tell you to avoid too much physical activity and stay off your feet. But there's no proof these things help.

How can I feel better after a miscarriage?

It's normal to feel grief, anger, and guilt after a miscarriage.

  • Consider talking with another person if you feel sad and are grieving the loss of your baby

  • Remind yourself that it’s very unlikely you did something to cause your miscarriage

  • If you’re worried about having another miscarriage, talk to a doctor who can discuss possible tests

  • Remember that many women who miscarry get pregnant again and give birth to healthy babies

NOTE: This is the Consumer Version. DOCTORS: Click here for the Professional Version
Click here for the Professional Version
Others also read

Test your knowledge

Loss of Smell
Anosmia is the total loss of smell. Most people with anosmia can taste sweet, sour, salty, and bitter substances but cannot distinguish among specific flavors. This is because the sense of smell makes it possible to distinguish among flavors, not taste receptors as many people erroneously believe. Which of the following is NOT a common cause of anosmia?
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID

Also of Interest

Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID