Miscarriage — the loss of a pregnancy before the twentieth week — is a common experience. An estimated twenty percent of known pregnancies end in miscarriage. The actual number of losses is 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. The chances of miscarriage decrease significantly once a fetal heartbeat has been detected on ultrasound or by Doppler stethoscope, and continue to decrease with each passing week during the first trimester.
The vast majority of miscarriages cannot be prevented; they are random events that are unlikely to recur. Most miscarriages are caused by chromosomal abnormalities. Other known (but much rarer) causes include infection, abnormalities of the uterus or cervix, smoking, substance abuse, physical trauma, exposure to environmental or industrial toxins, diabetes, thyroid disease, and autoimmune disease. In rare cases, women miscarry after diagnostic tests, such as chorionic villus sampling (CVS) or amniocentesis. Women over thirty are more likely than younger women to have a miscarriage.
About one in four women experience some vaginal bleeding or spotting during their first trimester. If the bleeding is light and lasts only one to two days, it isn’t associated with a greater risk of miscarriage. However, heavy bleeding is associated with miscarriage; about one in four women who experience heavy bleeding will go on to miscarry. If you have any vaginal bleeding during pregnancy, your health care provider can help determine if the bleeding is likely to result in miscarriage.
What to Expect in a Miscarriage
Many women learn about a miscarriage at a routine prenatal visit before experiencing any physical symptoms. Sometimes no embryo is seen on ultrasound, or the embryo may be much smaller than expected, or without a heartbeat. If you know that a miscarriage is inevitable, you may have a few options. You may be able to wait for the miscarriage to occur and complete itself naturally. This usually happens within two weeks. You may be able to take a drug, such as misoprostol, that causes uterine contractions and miscarriage within several days. Or you can schedule a minor surgical procedure known as a D&C (dilation and curettage), which involves dilating the cervix and using suction and/or a medical instrument called a curette to remove remaining pregnancy tissue. A D&C can be done in a clinic or doctor’s office, as an outpatient, or in a hospital or emergency room, with or without anesthesia. Some women feel like a D&C will provide a sense of control and closure; it also decreases the risk of infection and excessive bleeding.
For other women, the first signs of miscarriage are spotting or bleeding, followed by cramps in the lower back or abdomen. Other signs include fluid or tissue passing from the vagina. If you miscarry naturally or with medication, you will probably complete the miscarriage at home. The process may be over quickly or may take several days. Try to arrange for a trusted person to be with you through the process, throughout the night if needed. Think about where you will be most comfortable. Gather supplies such as bed liners, sanitary pads, and a hot water bottle. Some women find that massage is comforting and can help with the cramping. Your health care provider can prescribe pain medication to help you get through.
The bleeding will become heavier and cramping can be painful as the cervix dilates. If you are less than eight weeks pregnant when the miscarriage occurs, the expelled tissue will look no different from heavy menstrual bleeding. If you are further along in the pregnancy, you may see some blood clots and tissue that is firmer or lumpy-looking, which is placental or afterbirth tissue. The further along you are, the heavier the bleeding and more severe the cramps. Strong, painful cramps are normal, but if you have severe pain, seek medical care right away. In rare instances, a pregnancy can implant outside of your uterus (ectopic pregnancy), most often in one of the fallopian tubes. This is a medical emergency because an ectopic pregnancy can rupture and cause internal bleeding.
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 or persistent cramping, contact your health care provider. If pregnancy tissue remains in your uterus, your provider can perform a D&C to remove it and thereby prevent infection.
Physical recovery from a miscarriage ranges from a few days to a couple of weeks. Your period will return within four to eight weeks. Once bleeding has ceased and the cervix is closed, you can have insertive sex without being more at risk of getting an infection. Since it is difficult to know when the cervix has completely closed, most providers recommend waiting at least two weeks. A repeat pregnancy test after a few weeks is important to make sure your pregnancy hormone levels have returned to normal. If you feel dizzy or tired, tell your healthcare provider so you can be checked for anemia.
Emotional recovery may take longer. It is common to feel a range of emotions: sad, shocked, angry, out of control. Give yourself time. You may want to seek out others who have had miscarriages, either in person or online. Know that as difficult as they can be, miscarriages are a common part of the childbearing experience. The vast majority of women who miscarry go on to have healthy pregnancies.
First-trimester miscarriages are usually random events, unlikely to recur. However, a small number of women experience two or more miscarriages in a row, which is considered recurrent miscarriage. If this has happened to you and you want to get pregnant again, you may want to have medical tests to help identify the cause and see if anything can be done to prevent future miscarriages.
Your provider, an ob/gyn, or a fertility specialist can do blood tests on you and the father or donor to try to identify or rule out hormonal, immunological, or chromosomal abnormalities. Examinations of the uterus by ultrasound, hysteroscopy, hysterosalpingography, and/or an endometrial biopsy may also provide important information. The only definitive way to learn what caused a miscarriage is to have the fetal tissue from the miscarriage sent to a pathologist for genetic tests and a detailed microscopic examination.
If you have a D&C, the provider can save the fetal and afterbirth tissue for testing. If you are at home when you miscarry, you may be able to collect the tissue in a clean container. If you do, refrigerate the tissue until you can bring it to your care provider.
Once the testing has been done, ask to see all the pathology reports, and ask for a full explanation of all terminology. Most miscarriages are caused by a genetic issue. A small number of losses are caused by blood clots or immunologic abnormalities. About ten percent of the time, no specific cause can be found. If you are not satisfied with the explanation that is given to you, you can request that the loss tissue be examined by someone who specializes in analyzing pregnancy loss tissues.
Even if the cause cannot be determined after testing, you may be able to rule out likely causes of a repeat miscarriage, and you will know that you have done all you can to get an answer.