Early Miscarriage

figure 1

An early miscarriage is the spontaneous loss of pregnancy during the first 20 weeks of gestation. It is also called spontaneous abortion. (fig. 1).

Early miscarriage is very common. As many as 30% of women will experience one, usually before they even miss a period, or realize they are pregnant. Most early miscarriages are a result of a developing fetus that is unhealthy and has no chance of surviving to the end of pregnancy.

Some known causes of miscarriage include:

• Chromosomal abnormalities. Studies show that 50% to 60% of all miscarriages are caused by too little or too many chromosomes in the fetus. Of these cases about half are caused by Trisomy 21, also referred to as Down Syndrome.
• Low progesterone levels. The hormone progesterone is necessary for maintaining a healthy pregnancy. Insufficient levels may result in miscarriage. Early in pregnancy the progesterone is made by the small cyst in the ovary called the corpus luteum. After about nine to 10 weeks the placenta should be producing enough progesterone to support the pregnancy. Low level of progesterone that causes miscarriage is usually thought to be from inadequate production from the corpus luteum. Progesterone medication is safe and relatively inexpensive, but studies proving its effectiveness have not been conclusive. If you’ve had a miscarriage in the past, talk with your health care provider about whether progesterone is likely to help with your next pregnancy.
• Infections and diseases. Many bacterial and viral infections can contribute to a miscarriage, including viral infections, such as the cytomegalovirus, bacterial infections such as chlamydia, mycoplasma, ureaplasma, and streptococcus, or in rare cases parasitic infection such as toxoplasmosis. Disease, such as undiagnosed diabetes, may also cause a miscarriage.
• Age of the mother. The rate of miscarriage increases with the age of the mother. Around half of all pregnancies in women over 40 end in miscarriage.
• Other possible causes. Chronic illnesses, exposure to environmental toxins (such as certain metals), and stress. Examples include thyroid abnormalities (either overactive or underactive thyroid), poorly controlled diabetes, or intrauterine adhesions (most commonly caused by previous infections or procedures such as dilation and curettage). High dose radiation and chemotherapy are known toxins that can cause pregnancy loss. Industry employees working with chemicals such as dyes, metals, or solvents are at greater risk. Maternal stresses and heavy use of tobacco, caffeine, alcohol, and drugs can also be factors.
• Autoimmune diseases. The presence of certain complex antibodies such as the lupus anticoagulant and the anticardiolipin antibodies can cause miscarriages. These factors are not well understood, and there is no agreed upon effective treatment.

How Do I Know If I'm Having A Miscarriage?

• Vaginal bleeding. Especially heavy bleeding with passage of blood clots.
• Abdominal pain. Severe or persistent pain in the pelvis or lower back.
• Blood clots. Grayish matter may pass as the miscarriage begins. This is the embryo and placenta. If you do pass tissue at home your health care provider will likely instruct you to collect the tissue and place it in a clean jar or plastic bag to bring in for medical inspection.
• The early ending of morning sickness symptoms and loss of breast tenderness. Many women experience these symptoms in the first trimester, but by the beginning of the fourth month of pregnancy, they commonly subside. When women experience a loss of these symptoms earlier than the second trimester, and if symptoms subside abruptly, miscarriage may have occurred.

How Is It Treated?

• D & E (dilation and evacuation). During the surgery, the cervix is dilated or widened and both a suction curette and a sharp curette are used to empty the remaining tissue from the lining of the uterus.
• Vacuum aspiration. A mechanical pump is used to suction the remaining tissue out of the uterus.
• Medical management. The woman is given a medication that causes uterine contractions. Most women will pass the pregnancy within 24 hours of taking the medication. If miscarriage does not occur, the woman undergoes a surgical treatment (D and C or vacuum aspiration).

How Can I Prevent It?

Frequently Asked Questions

Review Date: 10/22/2008
Reviewed By: Peter J. Chen, MD, Department of Obstetrics & Gynecology, Hospital of the University of Pennsylvania, Philadelphia, PA. Review provided by VeriMed Healthcare Network.

A.D.A.M.'s health encyclopedia is accredited by URAC, also known as the American Accreditation Healthcare Commission (www.urac.org). URAC's accreditation program is the first of its kind, requiring compliance with 53 standards of quality and accountability, verified by independent audit. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial reviewers. A.D.A.M. is also a founding member of Hi-Ethics (www.hiethics.com) and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright 2002 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.