Health Library

Miscarriage

Definition

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. They often are unexpected and isolated events. About 15%-20% of recognized pregnancies end this way.

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

Causes

Miscarriages often occur for the following reasons:

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

In some cases, the cause is unknown.

Risk Factors

Factors that may increase the risk of miscarriage include:

  • Having an infection
  • Being older (maternal age of 35 years or older)
  • Smoking , drinking alcohol , or using drugs
  • Taking certain prescribed medicines
  • Being exposed to certain environmental toxins
  • Having a long-term condition that affects the immune system (eg, lupus, diabetes)
  • Having 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:

Symptoms

Symptoms include some or all of the following:

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

Recurrent Miscarriage

While miscarriage usually is a one-time occurrence, up to 1 in 20 couples experience two miscarriages in a row, and 1 in 100 have three or more. In some cases, these couples have an underlying problem. Couples who have experienced two or more miscarriages should have a complete medical evaluation to learn the cause and how they can prevent another one from occurring.

Cause of repeat miscarriages may include:

  • Chromosome problem in one member of the couple
  • Uterine abnormalities
  • Hormone problems
  • Immune system problems
  • Unknown causes

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 testing —to assess the health of the fetus
  • 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:

  • 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
  • Imaging tests—(eg, x-rays , ultrasound ) to identify a problem with your uterus
  • Endometrial biopsy —to check the uterine lining to see if it can support a pregnancy
  • Hysteroscopy—to examine the inside of the uterus

Treatment

Immediate care usually involves observation only, especially in early or first trimester miscarriages. Medicine 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.

Support Services

To help you deal with your loss, the doctor can refer you to a mental health therapist. You may also benefit from participating in a support group .

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 medicines 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 medicines 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

Resources

The American College of Obstetricians and Gynecologists
http://www.acog.org/

The International Council on Infertility Information Dissemination
http://www.inciid.org/

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

Canadian Resources

The Society of Obstetricians and Gynaecologists of Canada
http://www.sogc.org/

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

References

Miscarriage. American Pregnancy Association website. Available at: http://www.americanpregnancy.org/pregnancycomplications/miscarriage.html/ . Updated November 2011. Accessed August 10, 2012.

Miscarriage. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed/ . Updated August 3, 2012. Accessed August 10, 2012.

Miscarriage. March of Dimes website. Available at: http://www.marchofdimes.com/baby/loss%5Fmiscarriage.html . Updated October 2008. Accessed August 10, 2012.

12/2/2008 DynaMed's Systematic Literature Surveillance http://www.ebscohost.com/dynamed/what.php : 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/what.php : 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/what.php : Nakhai-Pour HR, Broy P, Bérard A. Use of antidepressants during pregnancy and the risk of spontaneous abortion. CMAJ. 2010 May 31.