Understanding Miscarriage

Losing a pregnancy can be heartbreaking. And unfortunately, miscarriages are fairly common. On average, about 1 in 5 pregnancies will end in a miscarriage — usually in the first trimester.

In most cases, a miscarriage cannot be prevented because it is the result of a chromosomal abnormality or problem with the development of the fetus. Still, certain factors — such as age, smoking, drinking, and a history of miscarriage — put a woman at a higher risk for losing a pregnancy.

While miscarriages usually cannot be prevented, by taking care of yourself and following your health care provider's recommendations, you can increase the chances that you and your baby will be healthy throughout the pregnancy.

What Is a Miscarriage?

A miscarriage is the spontaneous abortion of an embryo or fetus before it's developed enough to survive. This often happens even before a woman is aware that she is pregnant.

A miscarriage usually occurs in the first 3 months of pregnancy, before 12 weeks' gestation. A small fraction of miscarriages — less than 1% of them — are called stillbirths, as they occur after 20 weeks of gestation.

Symptoms of a Miscarriage

Many women don't even know that they've had a miscarriage (since they hadn’t known they were pregnant), thinking that it's just a particularly heavy menstrual flow.

Some women experience cramping, spotting, heavier bleeding, abdominal pain, pelvic pain, weakness, or back pain. Spotting is often not a sign of a miscarriage; many women experience it early on in pregnancy. But just to be safe, if you have spotting or any of these other symptoms anytime during your pregnancy, talk with your doctor.

Types of Miscarriage

If you think you may have had a miscarriage, your doctor may use a number of terms to explain what has happened:

• If a pregnant woman has bleeding, little or no pain, a closed cervix, and is found to still have a fetus with a heartbeat in her uterus, she may have had a threatened abortion. Most pregnancies with early bleeding but with a detectable heartbeat turn out fine.
• If you have miscarried, your doctor may say you have a blighted ovum, which is a miscarriage that has occurred so early that no clearly defined fetal tissues have formed.
• An inevitable miscarriage is when bleeding and cramping occur during pregnancy, with an open cervix.
• An incomplete miscarriage is when a miscarriage has occurred, but the body does not expel all the tissue from the pregnancy.
• A complete miscarriage is when all of the tissue from the pregnancy is expelled by the body.
• A missed miscarriage is when the fetus has died or has not developed, but the body does not discharge the fetus or tissues from the pregnancy. Sometimes women with missed miscarriages notice that they no longer "feel pregnant."

Stillbirths

A stillbirth, which many experts define as the death of a baby after the 20th week of pregnancy, can occur before delivery or during labor or delivery. It is rare and occurs in less than 1% of all births. A stillbirth also is sometimes referred to as intrauterine fetal death or antenatal death.

While there are some known risk factors for stillbirth (such as smoking, problems with the placenta, a pregnancy lasting longer than 42 weeks, and some infections), there is no way to predict when stillbirth will happen or who will have one, and the cause of many stillbirths remains unknown.

The first and most common sign of a stillbirth is decreased movement in the baby. Other possible signs include persistent cramping or stabbing pains in the pelvis, back, or lower abdomen, or vaginal bleeding. If you experience any of these symptoms, call your doctor immediately.

Your doctor can use an ultrasound to detect the heartbeat or give you an electronic fetal non-stress test, which involves lying on your back with electronic monitors attached to your abdomen. The monitors record the baby's heart rate, movements, and contractions of the uterus.

Why Do Miscarriages Happen?

The most common cause of pregnancy loss is a problem with the chromosomes that would make it impossible for the fetus to develop normally.

Other factors that could contribute to a miscarriage include:

• abnormal hormone levels in the mother, such as thyroid hormone
• uncontrolled diabetes
• exposure to environmental and workplace hazards, such as radiation or toxic agents
• certain infections
• uterine abnormalities
• incompetent cervix, or when the cervix begins to open (dilate) and thin (efface) before the pregnancy has reached term
• certain medications, such as the acne drug Accutane

Certain behaviors also increase the risk of a miscarriage. Smoking, for example, puts nicotine and other chemicals into the bloodstream, causes the fetus to get less oxygen, and increases the chance of losing a pregnancy. Alcohol and illegal drugs can also lead to miscarriages.

After a Miscarriage

If you have miscarried, your doctor will do a pelvic exam and an ultrasound to confirm the miscarriage. If the uterus is clear of any fetal tissue, or it is very early in the pregnancy, then there often won't be any more treatment.

But if the uterus still contains the fetus or other tissues from the pregnancy, this will need to be removed. The doctor may give you medicine to help pass the tissue or may need to dilate the cervix to perform a dilation and curettage (or D&C, which is a scraping of the uterine lining) or a dilation and extraction (or D&E, which is a suction of the uterus to remove fetal or placental tissue). You may have bleeding or cramping after these procedures, which are done with anesthesia.

If it is determined that your baby has died later in pregnancy, the doctor might decide to induce labor and delivery. After the delivery, the doctor will have the baby and the placenta examined to help determine the cause of death if it's still unknown.

If you've had several miscarriages, you may want to be evaluated to see if any anatomic, genetic, or hormonal abnormalities are contributing to the miscarriages.

Can Miscarriages Be Prevented?

Although miscarriages usually can't be prevented, you can take precautions to increase your chances of having a healthy pregnancy:

• Maintain a proper diet with plenty of folic acid and calcium.
• Take prenatal vitamins daily.
• Exercise regularly after you've gotten your doctor's OK.
• Maintain a healthy weight (women who are overweight or too thin may be more likely to have miscarriages).
• Avoid drugs and alcohol.
• Avoid deli meats and unpasteurized soft cheeses such as feta and other foods that could carry listeriosis.
• Limit caffeine intake.
• If you smoke, quit.
• Talk to your doctor about all medications you're currently taking. Unless your doctor indicates otherwise, many prescription and over-the-counter medicines should be avoided during pregnancy.
• Avoid activities that could cause abdominal trauma.
• Get immunized against communicable diseases and know your family medical and genetic history.
• Go to all of your scheduled prenatal appointments and discuss any concerns with your doctor.
• Call your doctor right away if you have fever, feel ill, notice decreased fetal movements, or are having bleeding, spotting, or cramping.

Trying Again

If you've had a miscarriage, it's important to take time to grieve. The loss of a baby during pregnancy is like the loss of any loved one. Give yourself time to heal emotionally and physically. Some health care providers recommend that women wait one menstrual cycle or more before trying to get pregnant again to give their bodies and psyches time to heal.

Some other things that can help you get through this difficult time:

• Attend a support group. Ask your doctor about local support groups for women who are trying again after a loss.
• Find success stories. Other women who have had a successful pregnancy after having a miscarriage can be a great source of encouragement to you. Your doctor may be able to give you the name of someone to talk with.
• Request frequent prenatal visits. Even if you aren't medically high-risk, when you do get pregnant, ask your doctor if you could schedule prenatal appointments more often for your own peace of mind.
• Be proactive. The more you know about the medical aspects of your pregnancy, the better you'll be able to discuss treatment options and outcomes with your doctor.
• Monitor the baby's movements. If you're far enough along — usually between 18 and 22 weeks — to feel kicks and jabs, keep a log of the baby's activities each morning and night and report any abnormalities or lack of movement to your doctor. If your baby isn't moving, eat or drink something sugary and lie down on your side. You should feel at least 10 movements in a 2-hour period. If you don't, call your doctor immediately.
• Try not to compare. No two pregnancies are exactly alike, so try not to dwell on any similarities between this pregnancy and the one that ended in a loss.
• Stay positive. Remember that before long, the pregnancy will be a distant memory and that there is a good end in sight.

Reviewed by: Larissa Hirsch, MD
Date reviewed: January 2012