According to the December 1999 news release from the U.S. government's National Center for Health Statistics, about 16% of recognized pregnancies end in miscarriage (i.e., prior to 20 weeks' gestation) or stillbirth (after 20 weeks' gestation). The medical term used for a miscarriage is spontaneous abortion, or early pregnancy loss. Most miscarriages occur during the first trimester of pregnancy. However, the statistics are unclear for the total number of recognized and unrecognized miscarriages in the United States. This is because a number of recognized miscarriages go undetected. When the pregnancy loss occurs early, the woman may not have missed her period yet. In this instance, she would not be aware of the pregnancy loss. Medical attention would not have been sought, and no statistic would have been generated.
Causes and symptoms
Causes of miscarriage may be genetic, anatomic, endocrinologic, infectious, immunologic, or exposure to a toxin. About 50–60% of first-trimester miscarriages occur as a result of a chromosomal abnormality, which renders the fetus non-viable. A definitive cause for the loss of a pregnancy cannot always be determined, as the products of conception (POC) are often passed by the woman at home or at work; they have not been collected for pathologic examination. The chromosomal abnormality is usually of spontaneous origin, a mutation that is not repeated in a subsequent pregnancy that continues to term.
A woman with a malformed uterus (e.g., bicornate) or cervix is also at increased risk for miscarriage. Women whose mothers took the medication diethylstilbestrol (DES) while they were in utero are especially likely to have suffered reproductive tract anomalies. The presence of fibroids can compete with the fetus for space and blood supply, and may result in miscarriage.
In about 17% of cases, a miscarriage is hormonal in nature, such as with insufficient secretion of progesterone, which results in a luteal phase insufficiency. Polycystic ovarian syndrome (PCOS), thyroid dysfunction, and poorly controlled diabetes mellitus are other hormonal causes of miscarriage.
Bacterial vaginosis, which may be present in as many as 31% of pregnant women, has been shown to increase the risk of miscarriage two fold, although it does not appear to affect a woman's ability to conceive. Individuals with a compromised immune system, causing them to be more susceptible to infectious organisms, are at increased risk of miscarriage. Toxoplasmosis can
Toxins and other workplace hazards that may increase the risk of miscarriage include:
- smoking, where the risk increases with each 10 cigarettes smoked daily
- caffeine, as in coffee, when four or more cups are consumed daily
- exposure to arsenic, lead, formaldehyde, benzene, and ethylene oxide
- multiple pregnancy, as in the case of carrying twins
- treatment with anticancer drugs, such as methotrexate
- exposure to ionizing radiation
The most common sign that a pregnancy is in danger is vaginal bleeding. The amount can vary from very light to heavy. The color of the blood varies as well, from brown to bright red. However, bleeding in early pregnancy is relatively common, and does not necessarily indicate impending miscarriage. One in four or five pregnant women experience bleeding in early pregnancy. Many women have some bleeding at the time of implantation, which occurs seven to 10 days after conception. Because of the possibility of pregnancy loss, any bleeding during pregnancy should be immediately reported to a woman's health care provider. The blood may be clotted, containing visible pieces of tissue. Bleeding may also be a sign of ectopic pregnancy, where the egg implants in a location other than the uterus, 95% of the time in a fallopian tube. Growth of the fertilized egg can lead to rupture of the tube, and can be life-threatening to the mother if untreated.
Cramping is another sign of a possible miscarriage. Cramping occurs as the uterus tries to expel the POC. The woman may also experience pain, dull and unrelenting, or sharp and intermittent, in the lower abdomen or back. When pain and bleeding persist, miscarriage is most likely to occur.
If a woman experiences any sign of potential miscarriage, she should be examined by her health care provider. The physician, nurse midwife or nurse practitioner will usually perform a pelvic examination to check whether the cervix is closed or open. The cervix should remain closed throughout the pregnancy, opening only at the time of labor and delivery. If the cervix is open, the miscarriage has either already taken place or is inevitable. The size, firmness, and tenderness of the uterus will be checked by the practitioner. Blood tests may be ordered to determine if the level of beta-hCG, which should have been rising as the pregnancy continued, has begun to decline. If bleeding has been heavy, blood work may be ordered to check the woman's hemoglobin (oxygen-carrying red blood cells; how much hemoglobin is in the blood) and hematocrit (volume of packed blood cells) levels. An ultrasound may also be conducted to see if miscarriage has already occurred, if the fetus is alive or dead, and to check for intrauterine versus extrauterine implantation. An ultrasound can also detect the presence of any uterine abnormalities.
The further into the gestation period, the more likely it is that the fetus and placenta may be expelled separately. If some of the POC has been retained, the miscarriage is referred to as an incomplete abortion. An incomplete abortion presents the risk of infection, which, left untreated and unpassed, can lead to a potential life-threatening sepsis. A missed abortion is defined by the death of the fetus that has remained in utero for several weeks. Most missed abortions terminate spontaneously.
Most miscarriages require no treatment. However, if infection has set in (i.e., indicated by fever and/or chills), or the POC have been retained, a D & C (i.e., prior to 16 weeks) or a D & E (i.e., after 16 weeks) may be required to remove any remaining tissue or blood clots from inside the uterus. An IV solution containing oxytocin may be used to induce uterine contractions to assist in complete expulsion of the POC, although this is not done in some practices. In early gestation (prior to six weeks), oral mifepristone (antiprogesterone RU 486) may be used to effect abortion. Two clinical studies, one in 1992 and another in 1993, demonstrated that the drug was effective as an abortifacient. In the earlier investigation, RU 486 administration to pregnant women was followed by a prostaglandin analogue; the success rate was 95%. In 1993, when a single 600-mg dose of RU 486 was given to women prior to six weeks' gestation, an 85% abortion rate was achieved.
Antibiotics will be prescribed in the event of infection, and may be ordered prophylactically. The woman is usually told to avoid the use of tampons and to abstain from sexual intercourse until the cervix has had a chance to close and heal. Rh-negative women will be given an injection of RhoGAM by the nurse. The purpose of this is to prevent Rh incompatibility between the mother and her baby in a future pregnancy.
Abortifacient—An agent that induces abortion.
Diethylstilbestrol (DES)—A synthetic estrogen drug used to treat several hormonal conditions. DES was used from 1938 until 1971, when it was found to cause reproductive tract defects in the children of women who took the drug while pregnant.
Dilation and curettage (D & C)—An obstetrical or gynecologic procedure in which the cervix is dilated and the contents of the uterus scraped and suctioned out. During pregnancy it is the term used until 16 weeks gestation.
Dilatation and evacuation (D & E)—An obstetrical procedure performed after 16 weeks gestation in which the cervix is dilated and the contents evacuated.
Embryo—The unborn child in the first eight weeks after conception. After the eighth week, the unborn child is called a fetus.
Mifepristone—A drug used to induce abortion. Also called RU-486.
Prostaglandin analogue—Any of a group of naturally occurring, chemically related hydroxy fatty acids that stimulate contractility of the uterine and other smooth muscle. These compounds have structures similar to those of others, but they differ in terms of a particular component.
Most miscarriages are uncomplicated and do not affect the woman's future ability to carry to term. About 90% of women who had one miscarriage have a successful pregnancy in the future. About 75% of women experiencing two miscarriages will carry to term in the future. Even women who have three consecutive miscarriages have a 50% chance of a successful fourth pregnancy. However, women who have had three or more miscarriages (repeated pregnancy loss [RPL]) may pursue further medical evaluation—earlier, if the woman is 35 or older. Following a miscarriage a woman should wait at least until she has had her next period before attempting to become pregnant again.
While the woman is able to recover physically from a miscarriage from within a few days to a couple of months, an emotional recovery may take much longer. Grieving the loss of the pregnancy may take some time for the woman, her partner, other family members, and even close friends. Some women may develop major depression, acute stress disorder, or even post-traumatic stress disorder (PTSD). Feelings of loss, of self-blame, of anger at a body that has "failed" them are all common.
Health care team roles
A nurse may be the first contact for the woman experiencing a miscarriage, either by telephone, at the clinic or doctor's office, or in the emergency department. The nurse's ability to create a calm environment, and to be supportive of the woman's grieving can enable the woman to move forward after the experience. The nurse should be able to supply the woman with information about miscarriage and community resources, such as support groups.
The ultrasound technologist may perform the ultrasound on the woman undergoing a miscarriage. Usually the technologist will give the report of the findings to the woman's practitioner, not to the woman directly. However, anxiety and fear can affect how information is heard and processed. The technologist's use of a soft, soothing voice can help calm the woman, better enabling her to hear the outcome of the ultrasound from her practitioner.
Because the majority of miscarriages are spontaneous chromosomal abnormalities, little prevention is available. However, regular screening for sexually transmitted diseases (STDs) and bacterial vaginosis can decrease the risks to a future pregnancy. If the miscarriage was due to a luteal phase deficiency, supplemental progesterone may be prescribed for future pregnancies.
If the nurse has telephone contact with the woman during the miscarriage, the nurse should request that the woman collect any tissue that is expelled—and collected, perhaps, on a sanitary pad. The nurse should ask the patient to bring it along with her to her next examination, so that it may be analyzed. While this may place an emotional burden on the woman, it can allow for the possible determination of the cause of the miscarriage. This information can help the woman and her practitioner prepare for a subsequent pregnancy. In addition, studies have shown that determining the cause can often assist the woman in overcoming her feelings of self-blame.
Creasy, Robert K., and Robert Resnik. Maternal-Fetal Medicine. Philadelphia: W.B. Saunders Company, 1999.
Fumia, Molly. A Piece of My Heart. Berkeley, CA: Conari, 2000.
Hinton, Clara H. Silent Grief; Miscarriage—Finding Your Way Through the Darkness. Green Forest, AK: New Leaf Press, 1998.
Kohn, Ingrid, and Perry-Lynn Moffitt. A Silent Sorrow. Pregnancy Loss: Guidance and Support for You and Your Family. New York: Routledge, 2000.
Pasquariello, Patrick S. Children's Hospital of Philadelphia: Book of Pregnancy and Child Care. New York: John Wiley & Sons, 1999.
Scott, James R., Philip J. Di Saia, Charles B. Hammond, and William N. Spellacy, eds. Danforth's Obstetrics and Gynecology. Philadelphia: Lippincott Williams & Wilkins, 1999.
"The Effects of Workplace Hazards on Female Reproductive Health." <http://www.cdc.gov/niosh>.
March of Dimes Birth Defects Foundation. 1275 Mamaroneck Avenue, White Plains, NY 10605. (888) 663-4637. <http://www.modimes.org>.
Resolve: The National Infertility Association.1310 Broadway, Somerville, MA 02144. (617) 623-0744. firstname.lastname@example.org. <http://www.resolve.org>.
Esther Csapo Rastegari, R.N., B.S.N., Ed.M.