Definition

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

Causes

Miscarriages often occur for the following reasons:

• Chromosomal abnormalities (common cause)
• Abnormalities in the uterine tract, such as fibroids
• Hormonal problems, such as not having enough progesterone, a female hormone needed to support pregnancy
• Factors related to the immune system, such as blood-clotting problems or rejection of the fetus
• Trauma

In some cases, the cause of miscarriage is unknown.

Risk Factors

Miscarriages are more common in women 35 years and older. Other factors that may increase your chance of having a miscarriage include:

• Infection
• Smoking, drinking alcohol, or using drugs during pregnancy
• Certain medications
• 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

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

• High blood pressure during pregnancy— pre-eclampsia
• Threatened miscarriage
• Induced labor
• Preterm delivery
• Low birth weight
• Postpartum hemorrhage

Symptoms

Miscarriage may cause:

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

Diagnosis

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 —to assess the health of the fetus
• Blood tests—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:

• Examination of the tissue that has passed through the vagina
• Blood tests—to check for a chromosomal error in the man or the woman or to check hormone and antibody levels
• Endometrial biopsy —to check the uterine lining to see if it can support a pregnancy

Imaging tests may be used to evaluate the uterus and surrounding structures. These may include:

• X-rays
• Ultrasound
• Hysteroscopy —to examine the inside of the uterus

Treatment

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 uterine contents are not spontaneously passed through the vagina. During a D&E, the doctor dilates the cervix, inserts a tool into the uterus, and suctions out remaining material.

Prevention

Before you start to plan your next pregnancy consider the following regarding your health:

• Is your diet ready to support another pregnancy?
• Are there habits you should change prior to another pregnancy?
• What medications are you taking and will they affect a pregnancy?
• How is your health?
• Are there issues you should resolve before trying another pregnancy?

If a specific cause of the miscarriage was found, certain treatments may help prevent future miscarriages. Treatments may include:

• Medications such as
  • Antibiotics to treat related infections
  • Hormone (progesterone) supplements
  • Aspirin and other medications to treat blood-clotting problems
• Surgery for uterine problems such as:
  • Uterine fibroids
  • Septate uterus (tissue in the center of the uterus)
  • Incompetent (weakened) cervix

March of Dimes http://www.marchofdimes.com/

Women’s Health Matters http://www.womenshealthmatters.ca/

Miscarriage. American Pregnancy Association website. Available at:
http://americanpregnancy.org/pregnancycomplications/miscarriage.html
Updated June 2014. Accessed August 19, 2014.

Miscarriage. March of Dimes website. Available at:
http://www.marchofdimes.com/loss/miscarriage.aspx
Updated July 2012. Accessed August 19, 2014.

Second trimester pregnancy loss. EBSCO DynaMed website. Available at:
http://www.ebscohost.com/dynamed
Updated February 28, 2014. Accessed August 19, 2014.

Recurrent pregnancy loss. EBSCO DynaMed website. Available at:
http://www.ebscohost.com/dynamed
Updated August 11, 2014. Accessed August 19, 2014.

12/2/2008 DynaMed’s Systematic Literature Surveillance
http://www.ebscohost.com/dynamed:
Winther JF, Boice JD Jr, Svendsen AL, Frederiksen K, Stovall M, Olsen JH. Spontaneous abortion in a Danish population-based cohort of childhood cancer survivors. J Clin Oncol. 2008;26:4340-4346.

4/16/2009 DynaMed’s Systematic Literature Surveillance
http://www.ebscohost.com/dynamed:
Bhattacharya S, Townend J, Shetty A, Campbell D, Bhattacharya S. Does miscarriage in an initial pregnancy lead to adverse obstetric and perinatal outcomes in the next continuing pregnancy? BJOG. 2008;115:1623-1629.

6/25/2010 DynaMed’s Systematic Literature Surveillance
http://www.ebscohost.com/dynamed:
Nakhai-Pour HR, Broy P, Bérard A. Use of antidepressants during pregnancy and the risk of spontaneous abortion. CMAJ. 2010 May 31.