Pregnancy & Birth

Causes of Childbearing Loss: Miscarriage

An estimated 15 to 20 percent of known pregnancies end in miscarriage, the loss of a pregnancy before the twentieth week.*  Most clinically recognized miscarriages occur between the seventh and twelfth week after a woman’s last menstrual period. The chances of miscarriage decrease significantly once a heartbeat has been detected on ultrasound or by Doppler stethoscope.

The vast majority of miscarriages cannot be prevented. Early losses often occur without a detectable embryo (sometimes there is just an empty sac or a “blighted ovum”). Up to 70 percent of first- trimester miscarriages, and 20 percent of second- trimester miscarriages, are caused by chromosomal anomalies from either the sperm or the egg cell.¹  Other known causes that are more likely to result in later miscarriages include infection, abnormalities of the uterus or cervix, smoking, substance abuse, exposure to environmental or industrial toxins, and autoimmune diseases. A serious physical trauma could cause a miscarriage. In rare cases, women miscarry after certain tests during pregnancy, such as chorionic villus sampling (CVS) or amniocentesis.

Many women learn about a miscarriage at a routine prenatal visit before experiencing any physical symptoms. The first symptoms of miscarriage are usually spotting or bleeding, followed by cramps in your lower back or abdomen. Other signs include fluid or tissue passing from the vagina.

Roughly two out of five pregnant women experience some vaginal bleeding or spotting during pregnancy, and only half of these women will miscarry.²  If you have any vaginal bleeding during pregnancy, your health care provider can help determine if the bleeding is likely to result in miscarriage or if it has another cause that does not threaten the pregnancy. If you are miscarrying, bleeding will become heavier and cramping can be painful as the cervix dilates. A loss after 9 to 10 weeks’ gestation may cause painful contractions.

If a blood test or sonogram indicates that you have had or are about to have a miscarriage, you may have a few options. Some women choose to allow the miscarriage to occur and complete itself naturally. Others find that scheduling a termination provides a sense of control and closure. There are several different ways to end the pregnancy. Medication treatment involves taking a drug, such as misoprostol, that causes uterine contractions and miscarriage, and can be used only early in the pregnancy. Other procedures (suction curettage, also known as dilation and evacuation, or D&E;) use an aspiration technique to remove any remaining tissue. All of these are outpatient procedures. The aspiration technique may be performed on an outpatient basis in a clinic, obstetrical office, hospital, or emergency room.

If you miscarry naturally or with medication, you will probably miscarry at home. The process may be over quickly or may take several days. The fetus, amniotic sac, and placenta, along with a large amount of blood, will be expelled. If you are less than 8 weeks pregnant when the miscarriage occurs, the expelled tissue will look no different from heavy menstrual bleeding. If you have reached 8 to 10 weeks, more tissue will be expelled and miscarrying can be more painful. In this instance, if you have chosen to allow the miscarriage to occur spontaneously, try to arrange for a trusted, knowledgeable person to be with you through the process, throughout the night if needed. Think about where you will be most comfortable and what you will need, such as bed liners and sanitary pads, or hot water bottles and massage to comfort you and help with cramping. You may want to think and talk about what you would like to do with the remains. There will be some blood clots, and you may notice tissue that is firmer or lumpy- looking, which is placental or afterbirth tissue. You may or may not see tissue that looks like an embryo or fetus.

Once everything in your uterus has been expelled, bleeding will continue, lessening over several days. If bleeding increases or stays bright red, or if you have foul- smelling discharge or a fever, contact your health care provider. If fetal tissue remains in your uterus, your provider can perform a D&E; to remove it and thereby prevent infection. A D&E; involves dilating the cervix and using suction (aspiration) and/or a medical instrument to remove remaining fetal and placental tissue.³

Once bleeding has ceased and the cervix is closed, you can have sex (including penetration) without risk of infection. Since it is difficult to know when the cervix has completely closed, most providers recommend waiting two weeks. A repeat pregnancy test after a few weeks is important to make sure your hormone levels are normal. If you feel dizzy or tired, ask to be checked for anemia. If you do not know your blood type, you should have a blood test.

If your blood type is Rh-negative, you will need a shot within seventy- two hours of the miscarriage. (If you are Rh-negative and you were carrying an Rh-positive fetus, there is a small chance that you have been exposed to Rh-positive blood cells from the fetal tissue during the miscarriage. A shot of RhoGAM prevents your body from producing antibodies to Rh-positive blood that could harm a fetus during a future pregnancy. For more information, see “The Rh-Negative Mother,” page 137.)

If you have a second-trimester miscarriage, or have had two or more earlier miscarriages, medical tests to help identify the cause are recommended. If you are at home when you miscarry, you may be able to collect fetal or afterbirth tissue in a clean container for examination at a hospital- based laboratory. Blood tests may identify or rule out hormonal, immunological, or chromosomal abnormalities in the parents or in any fetal tissue. Examinations of the uterus by ultrasound, hysteroscopy, and hysterosalpingography, or an endometrial biopsy, may also provide important information. Ask to see the pathology report, and ask for a full explanation of all terminology. Even if the cause cannot be determined—which is often the case—you will gain knowledge. You may be able to rule out likely causes of a repeat miscarriage and at least know that you have done all you can to get an answer.

Physical recovery from a miscarriage ranges from a few days to a couple of weeks. Your period will return within four to six weeks. Emotional recovery is likely to take longer. Give yourself time to grieve, search for medical explanations if there are any, and seek out other women who have miscarried.

Friends encouraged me to call their friends who had been through similar situations. This helped me tremendously. I loved talking to the woman in Oregon who had had four miscarriages before they discovered she had a blood-clotting disorder, or the woman in Boston who had three miscarriages and now had two small boys. These women became my friends.

End of Excerpt.

FOOTNOTES AND ENDNOTES

* The actual number may be significantly higher because many miscarriages occur very early on, before a woman knows she is pregnant, and may simply seem to be a heavy period on or near schedule.

1. March of Dimes Defects Foundation, Quick Reference and Fact Sheets, “Miscarriage” (2004), accessed at www.marchofdimes.com/professionals/681_1192.asp on July 10, 2006.

2. Mayo Foundation for Medical Education and Research, “Miscarriage” (2004), accessed at www.mayoclinic.com/health/miscarriage/PR00097 on July 10, 2006.

3. Ibid.

Excerpted from Chapter 9: Childbearing Loss in Our Bodies, Ourselves: Pregnancy and Birth  © 2008 Boston Women's Health Book Collective.