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Definition

Vaginal bleeding during pregnancy can cause worry. But it isn't always a sign of trouble. Bleeding in the first 12 weeks of pregnancy, also called the first trimester, is common. And most people who have bleeding during pregnancy go on to deliver healthy babies.

Still, take vaginal bleeding during pregnancy seriously. Sometimes bleeding during pregnancy could be a symptom of a miscarriage. Or sometimes bleeding might be a symptom of a condition that needs treatment right away.

Learn about the most common causes of vaginal bleeding during pregnancy. Then you'll know what to look for. And you'll know when to contact your healthcare professional.

Causes

Vaginal bleeding during pregnancy has many causes. Some causes are serious. But many aren't.

First trimester

Possible causes of vaginal bleeding during the first trimester include:

• Ectopic pregnancy The fertilized egg implants and grows outside of the uterus, such as in a fallopian tube.
• Implantation bleeding This happens about 10 to 14 days after conception when the fertilized egg settles into the lining of the uterus.
• Miscarriage This is the loss of pregnancy before the 20th week.
• Molar pregnancy Rarely, a fertilized egg grows into unusual tissue instead of a baby.
• Conditions of the cervix or vagina. These may include a cervical infection, an inflamed cervix or growths in the cervix such as polyps. For the vagina, there may be a wound, vaginal warts or growths.

Second or third trimester

Possible causes of vaginal bleeding during the second or third trimester include:

• Incompetent cervix Also called cervical insufficiency, this is when the cervix opens too early. It can lead to preterm birth.
• Miscarriage This is the loss of pregnancy before the 20th week.
• Placental abruption This is when the placenta comes away from the wall of uterus. The placenta gives nutrients and oxygen to the unborn baby, called a fetus.
• Placenta previa This is when the placenta covers the cervix. It often causes serious bleeding during pregnancy.
• Placenta accreta This is when the placenta grows too deep into the uterine wall.
• Preterm labor Starting labor too early might cause light bleeding.
• Conditions of the cervix or vagina. These may include a cervical infection, an inflamed cervix or growths in the cervix such as polyps. For the vagina, there may be a wound, vaginal warts or growths.
• Uterine rupture. The uterus tears open along the scar line from an earlier C-section or other past surgery on the uterus. This is rare but life-threatening.

Typical vaginal bleeding near the end of pregnancy

Light bleeding, often mixed with mucus, near the end of pregnancy could be a sign that labor is starting. This vaginal discharge is pink or bloody. It's called the bloody show.

When to see a doctor

Tell your healthcare professional about any vaginal bleeding during pregnancy. Be ready to say how much blood you passed, what it looked like and whether it had clots or tissue in it.

First trimester

During the first trimester, weeks one through 12:

• Tell your healthcare professional at your next prenatal visit if you have spotting or light vaginal bleeding that goes away within a day.
• Contact your healthcare professional within 24 hours if you have any vaginal bleeding that lasts longer than a day.
• Contact your healthcare professional right away if you have moderate to heavy vaginal bleeding, pass tissue from your vagina, or have any vaginal bleeding with belly pain, cramping, fever or chills.
• Tell your healthcare professional if your blood type is Rh negative and you have bleeding. You might need a medicine that keeps your body from making protein substances called antibodies that may harm future pregnancies.

Second trimester

During the second trimester, weeks 13 through 27:

• Contact your healthcare professional right away if you have any vaginal bleeding that lasts longer than a few hours or if you also have belly pain, cramping, fever, chills or contractions.

Third trimester

During the third trimester, weeks 28 through 40:

• Contact your healthcare professional right away if you have vaginal bleeding or vaginal bleeding with belly pain.

In the final weeks of pregnancy, vaginal discharge that is pink or bloody might be a sign of labor starting. That's called the bloody show. If you see pink or bloody discharge near the end of pregnancy, contact your healthcare professional to make sure what you're having is bloody show. Sometimes, it might be a sign of a pregnancy complication.