Miscarriage refers to the premature end of a pregnancy before the developing baby is able to survive outside the womb. Miscarriage can occur during the first or second trimester, before 20 weeks. Most occur in the first 12 weeks of pregnancy, and most miscarriages are unexpected and isolated events. About 15%-20% of recognized pregnancies end this way.

Some miscarriages cannot be explained. Miscarriages often occur for the following reasons:

• Chromosomal abnormality (most common cause)
• Advanced maternal age
• Uterine defects
• Fibroids
• Scar tissue from a past surgery
• Insufficient progesterone (a female hormone needed to support pregnancy)
• Infection in the genital tract
• Immunologic factors that may cause blood-clotting problems or rejection of the fetus

These factors increase your chance of having a miscarriage. Tell your doctor if you have any of these risk factors:

• Advancing maternal age
• Smoking
• Drinking alcohol at a level beyond two drinks per day
• Using illicit drugs (street drugs)
• Exposure to certain environmental toxins
• Infection, such as cytomegalovirus (CMV) and HIV
• Chronic maternal illness, eg, autoimmune diseases, such as lupus and insulin-dependent diabetes with uncontrolled blood sugar
• High-dose radiation therapy on the ovary and uterus or the pituitary gland during treatment for childhood cancer

Having a miscarriage during your first pregnancy may place you at a higher risk for complications during your next pregnancy. These complications may include:

• Pre-eclampsia
• Threatened miscarriage
• Induced labor
• Preterm delivery
• Low birth weight
• Postpartum hemorrhage

Symptoms include some or all of the following:

• Vaginal bleeding
• Pink or brown discharge
• Cramping
• Discharge of the products of conception (fetus, placenta, and surrounding membranes)
• Fever

You will be asked about your symptoms, the length of your pregnancy, and when you first noticed a change in your condition. The doctor will perform physical and pelvic exams.

Prior to miscarriage, tests may include:

• Ultrasound testing —to assess the health of the fetus or detect an ectopic pregnancy (a pregnancy in which development occurs outside the uterus)
• Blood test—to check the exact amount of the hormone (called human chorionic gonadotropin or hCG) important to sustain an early pregnancy

After miscarriage, tests may include:

• Tissue examination—to examine tissue that has been expelled and check for chromosome defects
• Blood tests—to check for a chromosomal error in the man or the woman or to check hormone and antibody levels
• Imaging tests—( x-rays or an ultrasound ) to identify a problem with your uterus
• Endometrial biopsy —reveals the suitability of your uterine lining to accept and sustain an embryo
• Hysteroscopy—to look inside the uterus. The hysteroscope, a thin, lighted fiberoptic instrument, is inserted in your vagina and passed through your cervix. The doctor can check for problems with the shape or size of your uterus, as well as examine and sample the endometrial lining. During the procedure, the doctor also may be able to correct a uterine problem.

Immediate care usually involves observation only, especially in early or first trimester miscarriages. Medication may be indicated in the event of heavy bleeding or cramping. A dilation and evacuation (D&E) may be needed if all uterine contents are not spontaneously expelled. During a D&E, the doctor dilates the cervix, inserts a tool into the uterus, and suctions out remaining material.

You may need professional counseling to recover emotionally from the loss.

The goal of long-term treatment is to prevent future miscarriages. This is geared toward whatever caused past losses.

Medications to decrease the chance of miscarriage may include:

• Antibiotics for infection
• Progesterone supplements (if this hormone is below normal levels)
• Aspirin and other medications to treat blood-clotting problems

Many uterine physical abnormalities can be corrected to decrease the chance of another miscarriage. If the cervix is weak, the doctor can place a stitch (called a cerclage), usually at the beginning of the second trimester of the next pregnancy, to keep it closed until you are ready to deliver. If fibroids are a contributing factor, removing them may prevent another loss.

Talking with a professional counselor often helps women deal with their loss. Some people benefit from participating in a support group.

If you are diagnosed with a miscarriage, follow your doctor's instructions .