Patient education: Pregnancy loss (Beyond the Basics)

INTRODUCTION — Pregnancy loss, also called "miscarriage," is when a pregnancy ends before 20 weeks from the last menstrual period.

Frequency of pregnancy loss — Pregnancy loss is common, especially in the first trimester.

Studies show that approximately 8 to 20 percent of people who know they are pregnant will experience loss some time before 20 weeks of pregnancy; 80 percent of these losses occur in the first 12 weeks [1]. The actual rate of pregnancy loss may be even higher since many people have very early losses and are never aware that they were pregnant.

If you are going through pregnancy loss, it can help to know that you are not alone.

How a pregnancy develops — To understand pregnancy loss, it can be helpful to understand the steps that happen when a person gets pregnant.

The female reproductive system includes the uterus (including the cervix), two ovaries, two fallopian tubes, and the vagina. The fallopian tubes are a pair of hollow tubes that run from each side of the uterus to the ovaries (figure 1). About once a month, an egg is released by one of the ovaries and travels down the fallopian tube. If the egg is fertilized in the tube by a partner's sperm, pregnancy begins. A person can also get pregnant with medical assistance, for example, via intrauterine insemination (IUI) or in vitro fertilization (IVF).

Once the egg and sperm join, they rapidly develop new cells. This bundle of cells, called an "embryo," normally implants on the inner wall of the uterus. Once implanted, the embryo continues to grow inside a sac of amniotic fluid. After 10 weeks of pregnancy, the embryo is called a "fetus."

CAUSES AND RISK FACTORS — Many factors can contribute to pregnancy loss. It is difficult to know with certainty what causes a particular pregnancy loss to occur, especially early in pregnancy.

Common causes — In most cases, pregnancy loss is not a result of anything the pregnant person did. When a cause is found, it commonly falls into one of the following categories:

●Problems with embryo development – As an example, in one-third of pregnancy losses occurring before 8 weeks, there is a pregnancy sac but no embryo inside. This means the egg was fertilized and the cells began to divide, but an embryo did not develop. In other cases, the embryo starts developing but has abnormalities. One study found that of more than 8000 pregnancy losses, 41 percent had chromosomal abnormalities.

●Medical conditions in the pregnant person – Certain health problems can lead to pregnancy loss. Examples include diabetes that is not well managed or structural problems in the reproductive tract, such as uterine fibroids. (See "Patient education: Care during pregnancy for patients with type 1 or 2 diabetes (Beyond the Basics)" and "Patient education: Uterine fibroids (Beyond the Basics)".)

Some studies have suggested that taking nonsteroidal anti-inflammatory drugs (NSAIDs) very early in pregnancy may increase the risk of pregnancy loss; however, there are conflicting data about this and evidence is limited. It is reasonable to avoid NSAIDs if you are trying to get pregnant. If you need to take NSAIDs to treat another medical problem and want to become pregnant, talk to your doctor. NSAIDs include ibuprofen (sample brand names: Advil, Motrin) and naproxen (sample brand name: Aleve).

Risk factors — Several risk factors can increase the rate of pregnancy loss. Some of these are within a person's control, while others are not. They include:

●Age – A person's risk of pregnancy loss increases as they get older. People older than 35 years are more likely to have a pregnancy loss than younger people. This is mostly because older people are more likely to have a pregnancy with a chromosomal abnormality.

●Previous pregnancy loss – Having had a pregnancy loss in the past may increase the risk for a future pregnancy loss. However, most people who have had a loss are able to have a healthy pregnancy in the future.

●Smoking – Smoking increases the risk of pregnancy loss.

●Alcohol – No amount of alcohol is known to be safe during pregnancy because it can cause health problems for the baby. Drinking alcohol also increases the risk of miscarriage.

●Fever – Pregnant people who develop fevers of 100°F (37.8°C) or higher appear to have an increased risk of pregnancy loss.

●Trauma – Trauma (injury) to the uterus can increase the risk of pregnancy loss. This can happen as a result of some forms of prenatal testing, such as amniocentesis or chorionic villus sampling. The effect of minor trauma to the pregnant person's abdomen is unknown, because during early pregnancy the uterus is generally cushioned and protected. (See "Patient education: Amniocentesis (Beyond the Basics)" and "Patient education: Chorionic villus sampling (Beyond the Basics)".)

●Other causes – Exposure to certain substances or conditions may increase the risk of congenital abnormalities and pregnancy loss. This includes exposure to certain infections, medications, radiation, physical stresses, and environmental chemicals.

It does not appear that caffeine intake increases the risk of miscarriage, with the possible exception of intake of very high levels (ie, 1000 mg, or 10 cups of coffee, over 8 to 10 hours).

PREGNANCY LOSS SIGNS AND SYMPTOMS — The most common signs of pregnancy loss are vaginal bleeding and abdominal pain early in pregnancy. If you experience either of these symptoms, it's important to be evaluated by your health care provider.

However, bleeding and discomfort can occur in normal pregnancies. In many cases, bleeding resolves on its own and the pregnancy continues normally without further problems.

DIAGNOSIS — The diagnosis of pregnancy loss is usually made based on some combination of your medical history, a pelvic exam, and an ultrasound.

In addition, it is important for your provider to confirm that the pregnancy is in the uterus. Pregnancies that develop outside the uterus (eg, in the fallopian tube) are called "ectopic" pregnancies; if this happens, it can be life threatening and requires immediate treatment. (See "Patient education: Ectopic (tubal) pregnancy (Beyond the Basics)".)

Physical examination — In some cases, pregnancy loss can be diagnosed based upon your symptoms and the physical exam (including checking to see whether the cervix is closed or open). However, in many cases of vaginal bleeding in early pregnancy, ultrasound is used to make a diagnosis.

Ultrasound — Ultrasound uses sound waves to visualize the structures inside the uterus. In early pregnancy, this is often done by inserting an ultrasound probe through the vagina. On an ultrasound, signs of pregnancy loss include no pregnancy sac, a pregnancy sac of a certain size without an embryo, or an embryo without cardiac (heart) activity.

If an embryo is seen on ultrasound, the doctor, nurse, or technician will measure its size. They will also examine the sac and other materials surrounding the embryo to see if there are any abnormalities.

Early cardiac activity — Around six weeks after the last menstrual period, fetal cardiac (heart) activity is typically visible on ultrasound. If the pregnancy has progressed to this stage or later, the absence of this motion during an ultrasound exam indicates that the pregnancy has likely ended.

On the other hand, the presence of a fetal cardiac activity (if there are no other abnormalities with the pregnancy) is a sign that the pregnancy is developing.

If you are more than 10 to 12 weeks pregnant, your health care provider can also use a device called a "Doppler" to listen to the fetal cardiac activity. A fetal heart rate that is less than 100 to 120 beats per minute can indicate that a pregnancy loss is likely.

Blood tests — Blood tests are not used to diagnose pregnancy loss, but some blood tests are helpful for your care. Your provider may order test such as blood hCG levels, blood type, and Rh status.

TREATMENT OPTIONS — Unfortunately, it is not possible to stop a pregnancy loss once it has started.

If your health care provider has confirmed that you are experiencing pregnancy loss, your options depend on your health, how far along your pregnancy was, and your preferences. The three main options are:

●Observation (waiting for the pregnancy tissue to pass on its own)

●Medication management (taking medications to help the pregnancy tissue to pass)

●Surgery (to remove the pregnancy tissue from your uterus)

This is a very personal choice. Each of the options is discussed in more detail below.

Observation — Observation, also called "expectant management," means waiting for the pregnancy tissue to pass on its own. When this happens, it might look and feel like a very heavy period, or you might see larger clots and pieces of tissue. You might also have cramping.

This may be an option if your pregnancy loss occurred before 13 weeks of pregnancy, your vital signs (blood pressure, pulse) are stable, and you do not have signs of infection.

●You might choose observation if you prefer to let things happen naturally, want more time to think about your options, or want to avoid surgical procedures.

●Challenges with observation include not knowing exactly when the bleeding will start, how heavy bleeding will be, or if the pregnancy tissue will pass completely.

In most cases, the pregnancy tissue will pass on its own within two weeks, although it sometimes takes as long as 3 to 4 weeks. Once this has happened, you will have an ultrasound to confirm that all of the tissue has passed.

If your body does not pass all of the tissue on its own, or if you have very heavy bleeding, you will need treatment with either medications or surgery.

Medical management — Medication management involves taking two different medications to cause the uterus to contract and pass the pregnancy tissue.

The medications typically used are mifepristone followed by misoprostol, taken over 24 to 48 hours. If mifepristone is not available, then misoprostol can be used alone, but it does not work quite as well by itself. The medicine can be taken by mouth or inserted into the vagina, and works over several days.

●You might choose medication management if you want more control over when your body will pass the pregnancy tissue, or want a highly effective treatment that does not include surgery.

●Challenges can include difficulty in getting the medications, possible need for a repeat treatment if all the tissue does not pass, and possible need for surgery if very heavy bleeding develops.

Surgical management — Surgical management for early pregnancy loss involves having the pregnancy tissue removed from the uterus during a procedure.

Your health care provider will insert a suction device through your cervix and into your uterus to remove the pregnancy tissue; this is called "uterine aspiration." Sometimes the cervix (the opening to the uterus) is dilated first; this is called "cervical dilation." (See "Patient education: Dilation and curettage (D&C) (Beyond the Basics)".)

●You might choose surgical management if you prefer not to for the pregnancy to pass on its own, were further along in pregnancy when the loss happened, have heavy bleeding or an infection, or wish to have tests performed on the pregnancy tissue.

●Challenges with surgical management include the possibility that not all tissue will be removed and you will require a second procedure, although this does not happen often. There is also a risk of complications such as infection, injury to the uterus, or very heavy bleeding. In very rare cases, additional surgery may be needed to stop bleeding or repair the uterus.

AFTER PREGNANCY LOSS

Emotional health — People experience a range of emotions following pregnancy loss. There is no right or wrong way to feel, and your feelings may change from day to day.

For some people, the loss of a pregnancy can cause significant grief. This can be strong and long-lasting. Try to take care of yourself. It can help to seek support from loved ones or connect with other people who have had similar experiences.

Talk with your health care provider if you are feeling profound sadness or depression following pregnancy loss, especially if it continues for more than a few weeks. Referral for grief counseling or other treatment may be helpful. (See "Patient education: Depression in adults (Beyond the Basics)".)

What to do or avoid — After a pregnancy loss, doctors recommend avoiding having vaginal sex or putting anything into the vagina, such as a douche or tampon, for two weeks.

If you wish to use birth control, this can be started immediately. (See "Patient education: Birth control; which method is right for me? (Beyond the Basics)".)

Medications — Your provider might prescribe medications to help decrease bleeding and reduce the risk of infection.

In addition, if you have an "Rh-negative" blood type (ie, A, B, AB, or O negative), you may need a drug called Rh(D) immune globulin (sample brand name: RhoGAM). This medicine helps protect future fetuses against problems that can occur if your baby is Rh-positive.

Pain management — People experience different levels of pain with pregnancy loss. This depends on the person as well as the type of management (eg, observation, medication, or surgery) as well as how far along the pregnancy was. Some people have significant uterine cramping.

Nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen (sample brand names: Advil, Motrin) can help reduce pain from cramping. If you are in a lot of pain and over-the-counter medications are not helping, talk with your health care provider.

Future pregnancy — While people who have had a pregnancy loss may be more likely to have another loss, it's important to remember that most people are able to go on to have a healthy pregnancy.

If you want to get pregnant again, you can start trying as soon as you feel ready, unless your health care provider has suggested waiting for medical reasons. For most people, there is no good evidence that waiting a certain amount of time will lower the risk of having another pregnancy loss.

While there is no way to ensure that you will not have another pregnancy loss, there may be some things you can do to lower your risk. For example, you can avoid smoking, alcohol, cocaine, and other substances. (See 'Risk factors' above.)

WHERE TO GET MORE INFORMATION — Your health care provider is the best source of information for questions and concerns related to your medical problem.

This article will be updated as needed on our website (www.uptodate.com/patients). Related topics for patients, as well as selected articles written for health care professionals, are also available. Some of the most relevant are listed below.

Patient level information — UpToDate offers two types of patient education materials.

The Basics — The Basics patient education pieces answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials.

Patient education: Pregnancy loss (The Basics)
Patient education: Coping after pregnancy loss (The Basics)
Patient education: Repeat pregnancy loss (The Basics)
Patient education: Dilation and curettage (D&C) (The Basics)
Patient education: Bleeding in early pregnancy (The Basics)
Patient education: Cervical insufficiency (The Basics)
Patient education: Hyperthyroidism (overactive thyroid) and pregnancy (The Basics)
Patient education: Pregnancy in Rh-negative people (The Basics)

Beyond the Basics — Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are best for patients who want in-depth information and are comfortable with some medical jargon.

Patient education: Care during pregnancy for patients with type 1 or 2 diabetes (Beyond the Basics)
Patient education: Uterine fibroids (Beyond the Basics)
Patient education: Amniocentesis (Beyond the Basics)
Patient education: Chorionic villus sampling (Beyond the Basics)
Patient education: Dilation and curettage (D&C) (Beyond the Basics)
Patient education: Birth control; which method is right for me? (Beyond the Basics)
Patient education: Depression in adults (Beyond the Basics)

Professional level information — Professional level articles are designed to keep doctors and other health professionals up-to-date on the latest medical findings. These articles are thorough, long, and complex, and they contain multiple references to the research on which they are based. Professional level articles are best for people who are comfortable with a lot of medical terminology and who want to read the same materials their doctors are reading.

Recurrent pregnancy loss: Definition and etiology
Effects of advanced maternal age on pregnancy
Recurrent pregnancy loss: Evaluation
Recurrent pregnancy loss: Management
Pregnancy loss (miscarriage): Clinical presentations, diagnosis, and initial evaluation
Pregnancy loss (miscarriage): Terminology, risk factors, and etiology
Antiphospholipid syndrome: Obstetric implications and management in pregnancy

The following organizations also provide reliable health information.

●National Library of Medicine

(www.medlineplus.gov/miscarriage.html, available in Spanish)

●The March of Dimes

(www.www.marchofdimes.org)