Miscarriage

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What is a miscarriage?

A miscarriage is the spontaneous loss of a pregnancy from conception to 20 weeks' gestation. The term stillbirth refers to the death of a fetus after 20 weeks' gestation. Miscarriage is sometimes referred to as spontaneous abortion, because the medical term abortion means the ending of a pregnancy, whether intentional or unintentional. Most miscarriages occur in the first trimester of pregnancy, between the 7th and 12th weeks of pregnancy.

How common is miscarriage?

Miscarriage is very common. Because many or even most miscarriages occur so early in pregnancy that a woman might not have known that she was pregnant, it is difficult to estimate how many miscarriages occur. Some experts believe that about half of all fertilized eggs die before implantation or are miscarried. Of known pregnancies (in which a woman misses a period or has a positive pregnancy test), about 10% to 20% end in miscarriage.

What causes miscarriage?

The majority of miscarriages are believed to be caused by genetic problems in the embryo that would prevent a baby from developing normally and surviving. These fatal genetic errors typically are not related to genetic problems in the mother.

In other cases, certain illnesses or medical conditions can cause miscarriage and may increase the risk of miscarriage. Mothers who have diabetes or thyroid disease are at increased risk of miscarriage. Infections that spread to the placenta, including some viral infections, can also increase the risk of miscarriage.

In general, risk factors for miscarriage include the following:

  • Older maternal age
  • Cigarette smoking (>10 cigarettes/day)
  • Moderate to high alcohol consumption
  • Trauma to the uterus
  • Radiation exposure
  • Previous miscarriage
  • Maternal weight extremes (BMI either below 18.5 or above 25 kg/m2)
  • Anatomical abnormalities of the uterus
  • Illicit drug use
  • Use of nonsteroidal anti-inflammatory drugs (NSAIDs) around the time of conception may increase the risk of miscarriage

Women who had one miscarriage have an incidence of miscarriage of about 20%, whereas women who have three or more consecutive miscarriages may have a risk as high as 43%.

Medically Reviewed by a Doctor on 6/30/2014

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Miscarriage - Causes Question: Please share your experience if you've had a miscarriage.
Miscarriage - Symptoms Question: What symptoms did you experience leading up to your miscarriage?
Miscarriage - Treatment Question: What treatments did your doctor administer after your miscarriage?
Miscarriage - Recurrent Miscarriages Question: Are you suffering from recurrent miscarriages? What is the underlying cause? Please share your experience.

Pregnancy After Miscarriage

Most women who miscarry later go on to have a healthy pregnancy and birth if no serious risk factors are present. Many women wonder about the right time to try to conceive again after miscarriage. From a purely physical point of view, the body heals rapidly from a miscarriage, and menstrual periods usually return within 4 to 6 weeks, meaning that it is possible for many women to become pregnant right away if they choose.


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