Bleeding During Pregnancy

Medically Reviewed by Jabeen Begum, MD on May 10, 2024
7 min read

Bleeding during pregnancy is common, especially during the first trimester. Usually, it's not a cause for concern. But because bleeding can sometimes be a sign of something serious, it's important to know the possible causes and get checked out by your doctor to make sure you and your baby are healthy.

Is bleeding normal during the first trimester?

Up to 25% of women have some vaginal bleeding during the first 12 weeks of pregnancy. Often this is normal and not a cause for concern. Many women who experience bleeding during this time go on to have normal pregnancies and deliver healthy babies.

Spotting during pregnancy or light bleeding is usually not concerning. But heavier bleeding that soaks a pantyliner or pad isn’t normal. Call your doctor right away to report any bleeding you have during the first trimester. Your doctor will help you figure out the cause and guide your next steps to keep you and your baby healthy.

What causes bleeding during the first trimester?

Possible causes of bleeding in the first trimester include:

Implantation bleeding. You may experience some normal spotting within the first 6-12 days after you conceive as the fertilized egg implants itself in the lining of the uterus. Some women don't realize they are pregnant because they mistake this bleeding for a light period. Usually, the bleeding is very light and lasts from a few hours to a few days.

Miscarriage. Because miscarriage is most common during the first 12 weeks of pregnancy, it tends to be one of the biggest concerns during the first trimester. However, first trimester bleeding doesn't necessarily mean that you’ve miscarried or will miscarry. If a fetal heartbeat is detected by ultrasound, your chance of miscarrying is lower, research suggests.

Other symptoms of miscarriage are strong cramps in the lower abdomen and tissue passing through the vagina.

Ectopic pregnancy. In an ectopic pregnancy, the fertilized embryo implants, or attaches, outside of the uterus, usually in the fallopian tube. If the embryo keeps growing, it can cause the fallopian tube to burst, which can be life-threatening to the mother. Although ectopic pregnancy is potentially dangerous, it only occurs in about 2% of pregnancies.

Other symptoms of ectopic pregnancy are strong cramps or pain in the lower abdomen and lightheadedness.

Molar pregnancy. Also called gestational trophoblastic disease, this is a very rare condition in which abnormal tissue grows inside the uterus instead of a baby. In rare cases, the tissue is cancerous and can spread to other parts of the body.

Other symptoms of molar pregnancy are severe nausea and vomiting. Your belly may also grow big very quickly as your uterus grows bigger.

Other causes of bleeding in early pregnancy include:

Cervical changes. During pregnancy, extra blood flows to the cervix. Having sex or a Pap test, both of which cause contact with the cervix, can trigger bleeding. This type of bleeding isn't cause for concern.

Infection. Any infection of the cervix, vagina, or a sexually transmitted infection (such as chlamydia, gonorrhea, or herpes) can cause bleeding in the first trimester. You’ll need treatment from your doctor if you have an infection.

Smoking. Smoking may cause abnormal bleeding during pregnancy. Talk with your doctor for support if you are pregnant and want to quit smoking.

Subchorionic hematoma. This happens when blood collects in the area where your baby’s amniotic sac attaches to your uterine wall. This collection of blood often goes away on its own without any symptoms but may sometimes cause light bleeding.

Abnormal bleeding in late pregnancy may be more serious because it can signal a problem with you or your baby. Call your doctor as soon as possible if you experience any bleeding in your second or third trimester.

What causes bleeding in the second and third trimesters?

Possible causes of bleeding in late pregnancy include:

Placenta previa. This condition occurs when the placenta sits low in the uterus and partially or completely covers the opening of the birth canal. Placenta previa is very rare in the late third trimester, occurring in about 1 in 200 pregnancies. A bleeding placenta previa, which can be painless, is an emergency requiring immediate medical attention.

Placental abruption. In about 1% of pregnancies, the placenta detaches from the wall of the uterus before or during labor, and blood pools between the placenta and uterus. Placental abruption can be very dangerous to both the mother and baby.

Other signs and symptoms of placental abruption are abdominal pain, clots from the vagina, tender uterus, and back pain.

Uterine rupture. In rare cases, a scar from a previous C-section can tear open during pregnancy. Uterine rupture can be life-threatening and requires an emergency C-section.

Other symptoms of uterine rupture are pain and tenderness in the abdomen.

Vasa previa. In this very rare condition, the developing baby's blood vessels in the umbilical cord or placenta cross the opening to the birth canal. Vasa previa can be very dangerous to the baby because the blood vessels can tear open, causing the baby to bleed severely and lose oxygen.

Other signs of vasa previa include abnormal fetal heart rate and excessive bleeding.

Premature labor. Vaginal bleeding late in pregnancy may just be a sign that your body is getting ready to deliver. A few days or weeks before labor begins, the mucus plug that covers the opening of the uterus will pass out of the vagina, and it will usually have small amounts of blood in it (this is known as "bloody show"). If bleeding and symptoms of labor begin before the 37th week of pregnancy, contact your doctor right away because you might be in preterm labor.

Other symptoms of preterm labor include contractions, vaginal discharge, abdominal pressure, and ache in the lower back.

Other causes of bleeding in late pregnancy are:

  • Injury to the cervix or vagina
  • Polyps
  • Cancer

Because vaginal bleeding in any trimester can be a sign of a problem, call your doctor. Wear a pad so that you can keep track of how much you're bleeding, and record the type of blood (for example, pink, brown, or red; smooth or full of clots). Bring any tissue that passes through the vagina to your doctor for testing. Don't use a tampon or have sex while you are still bleeding.

Your doctor might recommend that you rest as much as you can and avoid exercise and travel.

You should expect to receive an ultrasound to identify what the underlying cause of your bleeding may be. Vaginal and abdominal ultrasounds are often performed together as part of a full evaluation.

Heavy bleeding during pregnancy

Heavy bleeding during pregnancy isn’t normal. You’ll know you're bleeding heavily if you need to change your pad every 1-2 hours or you pass clots the size of a quarter or bigger. Call your doctor right away if you have heavy bleeding at any point while pregnant.

When to go to the emergency room

Go to the emergency room or call 911 right away if you have any of the following symptoms, which could be signs of a miscarriage or other serious problems:

  • Severe pain or intense cramps low in the abdomen
  • Severe bleeding, with or without pain
  • Discharge from the vagina that contains tissue
  • Dizziness or fainting
  • A fever of 100.4 F or higher and/or chills

Bleeding during pregnancy doesn’t always mean there’s a problem with you or your baby. Spotting or light bleeding during the first trimester is often normal and goes away on its own. However, heavy bleeding with or without other symptoms can be a sign of a serious problem. Keep track of the color, amount, and how long you’re bleeding. Call your doctor if you experience bleeding at any point during your pregnancy.

How much bleeding is normal in early pregnancy?

Spotting, or a few drops of blood that do not soak a pantyliner, is often normal in early pregnancy. Light bleeding, which may alarm you, usually goes away on its own and isn't a cause for concern. Always contact your doctor if you’re worried about the amount of vaginal bleeding you see.

Is bleeding during pregnancy an emergency?

Sometimes, but not always. Bleeding may be a sign of an emergency, especially if you have other symptoms such as abdominal cramps, pain, clots or tissue passing from the vagina, fever, and dizziness or fainting. Call 911 or go to the emergency room if you’re bleeding and have any of these symptoms.

Can you bleed heavily and still be pregnant?

Yes, you can bleed heavily and still be pregnant. Heavy bleeding doesn’t always mean you’ve miscarried. It may be a sign of preterm labor or another serious problem that needs medical attention right away to keep you and your baby healthy.

Can bleeding during pregnancy affect the baby?

Bleeding during pregnancy can affect the baby depending on the cause. Your doctor will examine you to figure out the cause of your bleeding and provide care that’s best for you and your baby.

Can stress cause vaginal bleeding?

More research is needed to say for sure. But stress during pregnancy can cause problems such as high blood pressure, having a preterm baby (born before 37 weeks), or having a baby with a low birth weight (less than 5 pounds, 8 ounces). Talk with your doctor if you are feeling stressed out. Managing your stress while pregnant will help you and your baby stay healthy.