How to Know If You're Hemorrhaging Due to a Miscarriage

Causes of hemorrhage

Verywell / Gary Ferster 

Why should you know about hemorrhage or heavy bleeding associated with miscarriage? When is bleeding normal and when is it too much? What are the possible causes of hemorrhage during a miscarriage, how is it treated, and what are the potential complications?

It's important to be aware of the signs and symptoms of excessive blood loss so that you can seek medical attention right away if needed. Hemorrhage during and after miscarriage is uncommon but is a leading cause of mortality related to miscarriages, especially second-trimester miscarriages.

Normal Bleeding Due to Miscarriage

Bleeding is normal after a miscarriage, but how can you know how much bleeding is too much?

Miscarriage is defined as pregnancy loss which occurs before week 20 of gestation and before a fetus would be able to survive outside of the womb. When a pregnancy is lost at any time between a missed period and 20 weeks, the blood vessels in the uterus have proliferated and both fetal and placental tissue has been built up to support the pregnancy. When a miscarriage occurs, this material is passed.

Causes of Miscarriage

The majority of miscarriages are caused by random chromosomal problems. If the cells in the fetus contain too many chromosomes, too few of them, or if they have structural abnormalities, a miscarriage may occur.

Miscarriages may also happen due to a blighted ovum (when a fertilized egg implants in the uterus but never becomes a viable fetus), drugs, alcohol, smoking, and possibly excessive caffeine intake during pregnancy. Sometimes a mother's own health conditions can also contribute, such as obesitiy, lupus, thyroid disease, diabetes, infections, and hormone problems.

If you're not sure whether you had a miscarriage, a doctor can use an ultrasound, pelvic exam, and a blood test (to measure your level of human chorionic gonadotropin or hCG) to answer that question.

Bleeding Due to Miscarriage

During a "normal" miscarriage, vaginal bleeding is usually heavier than a typical menstrual period and flow may contain tissue. So how can you know how much is too much? What qualifies as "normal bleeding" and what constitutes a "hemorrhage?"

Immediately seek medical help if your bleeding is heavy enough to soak through a menstrual pad (regular, not maxi or mini) in less than an hour.

It's also important to seek immediate medical assistance if you have any symptoms that could suggest an ectopic pregnancy, regardless of the amount of bleeding. Symptoms of a ruptured ectopic pregnancy may include the sudden onset of pain in your abdomen or back, a rapid pulse, lightheadedness, or loss of consciousness.

Excessive Bleeding Due to Miscarriage

It is possible to experience heavier than normal bleeding after a miscarriage. There are different ways that your healthcare provider defines excessive bleeding and techniques that you can use to determine if yours is typical or not.

Definition of Hemorrhage

To understand the meaning of "hemorrhage" let's first talk about normal bleeding. During a normal menstrual period, you will pass roughly 80 ccs of blood. One teaspoon is equivalent to 5 ccs, so a normal period would result in roughly 16 teaspoons or 5 tablespoons of blood.

In contrast, the amount of bleeding with a normal vaginal delivery is roughly 500 cc. A miscarriage usually results in the loss of an amount of blood between these numbers, but closer to that of a regular period.

Hemorrhage refers to excessive blood loss and is divided into categories based on the percent of blood present in your body

  • Category I - up to 15% of blood volume
  • Category II - loss of 15 to 30% of blood volume
  • Category III - loss of 30 to 40% of blood volume
  • Category IV - loss of over 40% of blood volume

Since most people don't have a simple way to calculate the percentage of their body's blood supply they have lost, there are many ways in which to estimate blood loss.

How to Estimate Your Blood Loss

It may be helpful for you to understand excessive bleeding in terms of menstrual pads. If you bleed through a pad in less than 2 hours, your bleeding may be excessive. If you bleed through a large pad in less than 1 hour, you need to seek help right away. It's also important to note that blood loss might look even more excessive in a toilet bowl full of water.

You may hear about other symptoms which could indicate blood loss. It's important to seek medical help before these symptoms occur. For example, you may hear that with excess bleeding your heart rate will increase (tachycardia.) Yet as much as 30% of your blood may be lost before a rapid heart rate occurs. The same is true for other symptoms and signs of blood loss and anemia.

If your blood pressure drops, or you if you appear pale and sweaty, you have already lost too much blood and should call 911.


There are several possible causes for bleeding after a miscarriage, but by far the most common is retained products of conception or an incomplete miscarriage.

When products of pregnancy remain in your uterus, the normal contracting of your uterus that takes place after a miscarriage does not occur. (When this does not occur after a full term delivery it is called uterine atony.) In order for your bleeding to stop, removal of the products of conception must occur. A D&C procedure to evacuate the uterus may be needed.

In addition to an incomplete miscarriage, other less common but important causes include:

  • AV fistulas (where arteries connect directly with veins in your uterus or cervix)
  • Bleeding disorders such as hemophilia and von Willebrands disease (von Willebrand disease affects 1% of the population and many women are not aware of the condition until they bleed excessively after a miscarriage or delivery)
  • Blood thinning medications (drugs such as Heparin, though it's important to note that some herbal preparations can cause bleeding as well)
  • Choriocarcinomas (a very uncommon tumor of the uterus)
  • Ruptured ovarian cysts
  • Shock followed by disseminated intravascular coagulation (DIC)


An ultrasound can often help with the diagnosis of an incomplete miscarriage, with thickening of the uterine wall being seen. In making a diagnosis your doctor will also look at your history (particularly the gestational age of your pregnancy) and physical exam (whether your cervix is open and whether any products of conception are present.)


Treatment of hemorrhage after a miscarriage can be a medical emergency. The first step is to ensure that you are stable, evaluating the emergency measures common to any emergency—airway, breathing, and circulation.

A large IV is usually placed and intravenous fluids were given. Your blood will be drawn for type and crossmatch so that a blood transfusion can be given if necessary. The next step is to quickly evaluate the cause of your bleeding.

Your provider will rule out the less common causes of bleeding such as a viable pregnancy with a ruptured ovarian cyst, bleeding disorders, etc and then resolve the source of your bleeding. Most often this means an emergency D&C (dilation and curettage) to remove the products of conception. Medications may be used to aid in the contraction of your uterus after these are removed.


During a miscarriage, the bleeding and the painful abdominal cramps (the other major symptom of miscarriage) tend to occur the most when you are passing the placenta and the sac through your vagina. This process can usually take anywhere from 60 minutes to a few hours.

If you are not able to pass those tissues naturally by yourself, a doctor can help remove it by using a medical procedure called dilation and curettage (often referred to as a D&C). Following the miscarriage, you may bleed a little bit over the next two weeks or so, but the amount of blood should gradually decrease. Your normal menstrual cycle should return within roughly six weeks.


Hemorrhage with a miscarriage is a life-threatening complication and emergency medical care is needed. Without emergency help, shock and even death could occur. Severe blood loss may result in a lack of blood flow to the brain, and complications related to hypoxia (lack of oxygen in the tissues of the body) are possible if emergency treatment is delayed.

Complications related to D&C include infection, bleeding, perforation of uterus, need for transfusion or need for further surgery including hysterectomy. These are rare when standard medical practice standard are adhered to. Following hemorrhage related to miscarriage, it can take some time for your blood counts to return to normal, and it's important to take it easy during this time. Iron supplementation or less commonly, transfusion might be needed.

If you are looking at the literature do not be alarmed if you see articles talking about abortion. Physician's use the term "abortion" to describe both abortions and miscarriages, with intentional abortions being called "elective abortions" and miscarriages being called "spontaneous abortions."


A miscarriage can be extremely painful both physically and emotionally. Fluctuating hormone levels may contribute to these symptoms. It's natural to feel depressed, confused, and angry after the fact, and talking with other women who have also been through it may help you cope. There are many excellent online support communities available to help those who have experienced pregnancy loss, and several organizations that support people who have coped with a miscarriage.

Most importantly, give yourself time to grieve. You are likely to hear a plethora of platitudes from friends and family which can sometimes serve to make you feel worse. We know that it doesn't help to hear that you are young or that you can try again. You need to grieve this pregnancy. Pamper yourself during this time.

5 Sources
Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  4. Centers for Disease Control and Prevention. Data and statistics on von Willebrand Disease.

  5. Condous G. Ultrasound diagnosis of miscarriage: new guidelines to prevent harmAustralas J Ultrasound Med. 2011;14(4):2. doi:10.1002/j.2205-0140.2011.tb00127.x

Additional Reading

By Krissi Danielsson
Krissi Danielsson, MD is a doctor of family medicine and an advocate for those who have experienced miscarriage.