Definition

Miscarriage is the end of a pregnancy before the baby is able to survive outside the uterus. Miscarriage can occur during the first or second trimester, before 20 weeks. Most happen in the first 12 weeks of pregnancy. They often are unexpected and isolated events.

Fetus in First Trimester Copyright © Nucleus Medical Media, Inc.

Causes

For some, the cause of miscarriage is unknown. Miscarriages can also occur for the following reasons:

• Problems in the chromosomes (common cause)
• Abnormal structure or issues in the uterine tract, such as fibroids
• Problem with hormones, such as not having enough hormone (progesterone) to support pregnancy
• Immune system-related problems, such as blood-clotting problems or rejection of the fetus
• Trauma

Risk Factors

Miscarriages are more common in women 35 years and older. Other things that may increase the chance of a miscarriage are:

• Infection
• Smoking, drinking alcohol, or using drugs during pregnancy
• Certain medicine
• Exposure to certain environmental toxins
• Autoimmune disorders, such as systemic lupus erythematosus
• High-dose radiation therapy on the ovaries, uterus, or the pituitary gland during treatment of childhood cancers

Symptoms

Miscarriage may cause:

• Vaginal bleeding
• Pink or brown discharge
• Cramping
• Passing the fetus, placenta, and surrounding membranes through the vagina
• Fever

Diagnosis

The doctor will ask about symptoms, length of pregnancy, and when changes happened. Physical and pelvic exams will be done. Passed tissue may be examined. The uterus may also be examined with:

• Ultrasound
• Hysteroscopy—to examine the inside of the uterus

Treatment

Early or first trimester miscarriages may only need observation. Medicine may be needed if there is heavy bleeding or cramping.

A dilation and evacuation (D&E) may be needed if all tissue does not pass through the vagina. The doctor will remove remaining tissue.

Prevention

Treatment may help prevent future miscarriages if a specific cause was found.