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Understanding Miscarriage

Losing a pregnancy can be heartbreaking. And for some expectant couples, the fear of having a miscarriage can be consuming, even edging out the excitement about being pregnant.

Unfortunately, miscarriages are fairly common. On average, 1 in 5 pregnancies will end in a miscarriage — most of which occur in the first trimester.

In most cases, a miscarriage cannot be prevented because it is the result of a chromosomal change or problem with the fetus that occurs during conception or during early fetal development. That said, certain factors — such as age, smoking, drinking, and a history of miscarriage — put a woman at a higher risk for losing a pregnancy.

But you can do many things to 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 can happen 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, 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 not always 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 opening cervix.
  • An incomplete miscarriage is when a miscarriage has occurred, but the body does not expel all the elements of the pregnancy.
  • A missed miscarriage is when the body does not discharge the fetus, the placenta, or other elements for several weeks — this might occur when the woman has neither menstrual periods nor any signs of pregnancy.
  • A recurrent miscarriage is when a woman miscarries three or more consecutive pregnancies.

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, high blood pressure, and diabetes), 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 and Stillbirths Happen?

The most common cause of pregnancy loss is a random chromosome abnormality that occurs during fertilization. For fertilization to occur, the chromosomes in the nucleus of both the egg and the sperm need to join into 23 pairs (46 total chromosomes). Sometimes this pairing does not happen correctly and that can impede the development of the fetus.

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.

Some Causes of Stillbirth

  • pre-eclampsia and eclampsia, disorders of late pregnancy that involve high blood pressure, fluid retention, and protein in the urine
  • uncontrolled diabetes
  • infectious diseases — such as syphilis, toxoplasmosis, herpes, rubella, influenza, malaria, or listeriosis
  • severe birth defects (responsible for about 20% of stillbirths), including defects such as spina bifida
  • postmaturity — there is a small increase in the number of stillbirths when a pregnancy has lasted 42 weeks or longer
  • chronic high blood pressure, lupus, heart or thyroid disease

Sometimes doctors do not know what caused a stillbirth.

After a Miscarriage or Stillbirth

If you have miscarried, your doctor will do a pelvic exam and an ultrasound test 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 portions of the fetus, 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 (D&C, a scraping of the uterine lining) or a dilation and extraction (D&E, a suction of the uterus to remove fetal or placental tissue). You may have spotting or mild cramping after these procedures, which are done under local or general anesthesia so there is no immediate pain.

If it is determined that your baby has died in utero 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 or Stillbirths Be Prevented?

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

  • Maintain a proper diet loaded with folic acid and calcium.
  • Exercise after you've gotten your doctor's OK.
  • Maintain a healthy weight (women who are overweight or too thin are more likely to have miscarriages).
  • Avoid drugs and alcohol.
  • Avoid deli meats and soft cheeses such as feta and other foods that could carry listeriosis.
  • Limit caffeine drinks to no more than 1 to 2 cups a day.
  • 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 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 or stillbirth, it's important to take time to grieve. The loss of a baby during or shortly after 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 3 months (three menstrual cycles) 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 made it through a subsequent 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 focused on your goal. You may feel like you've been pregnant forever, but it helps to 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: June 2008

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