A miscarriage is a pregnancy loss before 20 weeks of pregnancy.
Miscarriages are very common, especially early in pregnancy.
Bleeding and cramping may be symptoms of a miscarriage.
Doctors check the fetal status with ultrasonography and do a pelvic examination.
If a miscarriage is confirmed, a woman may wait to pass the pregnancy tissue, or she may take medications or have a procedure to help with this process.
A miscarriage occurs in about 10 to 15% of confirmed pregnancies. Many more miscarriages are unrecognized because they occur before a woman knows she is pregnant. About 85% of miscarriages occur during the first 12 weeks of pregnancy. The remaining 15% of miscarriages occur during weeks 13 to 20. When a woman wants to be pregnant and have a child, a miscarriage is often emotionally difficult for her and her partner, and they may need support from loved ones and health care professionals.
Miscarriages are more common in high-risk pregnancies, particularly when women are not receiving adequate medical care.
Causes of Miscarriage
Most often, the cause of miscarriage is unknown.
Miscarriages that occur during the first 10 to 11 weeks of pregnancy are often caused by a chromosome disorder. This occurs more frequently in women who are younger than 20 years old or are 35 or older.
Anatomic abnormalities in the woman's reproductive tract (for example, a uterus that has fibroids or, rarely, 2 chambers or internal scarring) may also cause pregnancy loss through 20 weeks of pregnancy. A miscarriage may result from certain viral infections, such as a cytomegalovirus infection or rubella. Other causes include medical conditions, such as diabetes or autoimmune disorders.
If women have a disorder that causes blood to clot too easily (such as antiphospholipid syndrome), they may have repeated consecutive miscarriages (called recurrent pregnancy loss) that occur before 10 weeks of pregnancy.
Risk factors (conditions that increase the risk of a disorder) for miscarriage include the following:
Younger or older maternal age (younger than 20 years or age 35 or older)
Miscarriages in previous pregnancies (repeated miscarriages)
Use of substances such as and alcohol
Certain disorders in the mother, such as diabetes, high blood pressure, or severe thyroid disorders, if they are not appropriately treated and controlled during pregnancy
Major physical trauma can cause miscarriage, but it is unlikely to be caused by minor force or injury (such as from slipping and falling or exercise). Sudden emotional shock (for example, from receiving bad news) is not linked with miscarriage.
Understanding the Language of Pregnancy Loss
Doctors may use the term abortion to refer to a miscarriage, because the medical term is spontaneous abortion. The medical term for intentional termination of pregnancy is called induced abortion or voluntary interruption of pregnancy. Terms for abortion include the following:
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Symptoms of Miscarriage
A miscarriage is usually preceded by vaginal bleeding, which may be spotting with bright or dark red blood or heavier bleeding. The uterus is a muscle, and it contracts during miscarriage, causing cramps. This may cause the cervix to open (dilate). However, vaginal bleeding is common in early pregnancy and often there is no problem with the pregnancy. About 25% of pregnant women have some bleeding at least once during the first 12 weeks of pregnancy. Approximately 12% of pregnancies with bleeding during the first 12 weeks result in a miscarriage.
Early in a pregnancy, the only sign of a miscarriage may be a small amount of vaginal bleeding. Later in a pregnancy, a miscarriage may cause profuse bleeding, and the blood may contain mucus or clots. Cramps become more severe until, eventually, the uterus contracts enough to expel the fetus and placenta.
Sometimes a fetus stops developing, but no symptoms of miscarriage occur. This is called a missed abortion. Doctors may suspect a missed abortion if the uterus does not enlarge. Sometimes, doctors detect a missed abortion on a routine prenatal ultrasound.
If any fragments of a fetus or placenta remain in the uterus after a miscarriage, infection may develop. Infection of the uterus that occurs during or shortly before or after a miscarriage or induced abortion is called a septic abortion. This infection can be very serious and even life threatening. A woman should seek medical care if abdominal pain or vaginal bleeding persists or worsens a few days after a miscarriage or if she has a fever.
Did You Know...
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Diagnosis of Miscarriage
A doctor's evaluation
Ultrasonography
Blood tests
If a pregnant woman has bleeding and cramping during the first 20 weeks of pregnancy, a doctor examines her to determine whether a miscarriage is likely. During a pelvic examination, a doctor examines the cervix to determine whether it is dilating. If it is not, the pregnancy may be able to continue. If it is dilating before 20 weeks of pregnancy, a miscarriage is highly likely.
Sometimes a doctor uses a device to listen for the fetal heartbeat. Also, ultrasonography is done using a device inserted into the vagina (called transvaginal ultrasonography). Ultrasonography may be used to determine whether a miscarriage has already occurred or, if not, whether the fetus is still alive. If a miscarriage has occurred, ultrasonography can show whether the fetus and the placenta have been completely expelled.
Usually, doctors do blood tests to measure a hormone produced by the placenta early in pregnancy called human chorionic gonadotropin (hCG). Results confirm the pregnancy. Usually, the test is repeated every several days or once a week to determine whether a woman has a mislocated (ectopic) pregnancy, which can also cause bleeding, and also to make sure that the miscarriage process has been completed.
If the uterus does not progressively enlarge, doctors suspect a missed abortion. That is, the fetus has died but has not been expelled from the uterus or caused symptoms (vaginal bleeding or abdominal pain).
If a woman has had 2 or more miscarriages, she may want to see a doctor before trying to become pregnant again. The doctor can check for genetic or structural abnormalities and for other disorders that increase the risk of a miscarriage. For example, doctors may do the following:
An imaging test (such as ultrasonography, hysteroscopy, or hysterosalpingography) to look for structural abnormalities of the female reproductive system
Blood tests to check for certain disorders, such as antiphospholipid syndrome, diabetes, reproductive hormone abnormalities, and thyroid disorders
Genetic tests to check for chromosome abnormalities
If identified, some causes of recurrent miscarriage can be treated, making a successful pregnancy possible in the future.
Treatment of Miscarriage
No treatment, if the pregnancy tissue has completely passed
Observation of symptoms and waiting for the pregnancy tissue to pass on its own
Medications or a procedure to help remove the pregnancy tissue
Pain medication, as needed
Rho(D) immune globulin if the mother has Rh-negative blood
Emotional support
If there is a threatened miscarriage (symptoms are occurring but ultrasonography shows a normal pregnancy), some doctors advise women to avoid strenuous activity and, if possible, to stay off their feet and avoid sexual activity. However, there is no clear evidence that such limitations are helpful.
If a miscarriage is confirmed and the fetus and the placenta have been completely expelled, no further treatment is needed.
If a miscarriage is confirmed, but all or some of the tissue from the fetus or placenta remains in the uterus, there are usually several options for passing or removing the pregnancy tissue.
For an early miscarriage (before 12 weeks of pregnancy), if a woman does not have heavy bleeding or signs of infection, doctors usually explain several options, and a woman may choose to do one of the following:
Closely monitor symptoms and wait for the uterus to expel the tissue on its own: A woman should receive instructions about what to expect, how to manage pain, how to recognize if the pregnancy tissue has passed, and when to call a doctor (if bleeding or pain is different than the usual for a miscarriage or a fever occurs). If the pregnancy tissue does not pass on its own, medication or a procedure is necessary.
Have a procedure to remove the pregnancy tissue from the uterus: Usually, a flexible tube is inserted through the vagina into the uterus and suction is used (dilation and curettage [D & C] with suction).
If a miscarriage has passed on its own, doctors usually do blood tests for the pregnancy hormone hCG once a week until the level is undetectable, to confirm that no tissue from the fetus or placenta remains in the uterus.
For a late miscarriage (between 12 and 20 weeks), doctors usually advise not to wait for the pregnancy to pass on its own, because this may cause serious pain or bleeding, and the pregnancy may not pass completely, causing infection. Late miscarriages are treated with one or more of the following options:
A procedure to remove the pregnancy tissue from the uterus: This is called a dilation and curettage (D & C) or dilation and evacuation (D & E) and is done with suction and/or other surgical instruments that are inserted through the vagina into the uterus.
Pain relievers are given as needed.
All women who have an Rh-negative blood type and have had a miscarriage are given Rho(D) immune globulin to prevent hemolytic disease of the fetus (erythroblastosis fetalis). This disorder is caused by Rh incompatibility (when a pregnant woman has Rh-negative blood and the fetus has Rh-positive blood).
Emotions after miscarriage
After a miscarriage, a woman and her partner may feel grief, sadness, anger, guilt, or anxiety about subsequent pregnancies.
Grief: Grief for a loss is a natural response and should not be suppressed or denied. Talking about their feelings with another person may help women deal with their feelings and gain perspective.
Guilt: Women may think that they did something to cause the miscarriage. Usually, they have not. Women may recall taking a common over-the-counter medication early in pregnancy, drinking a glass of wine before they knew they were pregnant, or doing another everyday thing. These things are almost never the cause of a miscarriage, so women should not feel guilty about them.
Anxiety: Women who have had a miscarriage may wish to talk with their doctor about the likelihood of a miscarriage in subsequent pregnancies and be tested if needed. Although having a miscarriage increases the risk of having another one, most of these women can become pregnant again and carry a healthy baby to term. Additional testing is usually not necessary unless women have had 2 or more miscarriages.
Doctors offer their support and, when appropriate, reassure women that the miscarriage was not their fault. Formal counseling is rarely needed, but doctors make it available for women who want it. Support groups may be helpful.
