The spontaneous loss of pregnancy during the first 20 weeks of gestation. Also called spontaneous abortion.
Early miscarriage is a very common part of pregnancy. 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 developing fetus that is unhealthy and has little chance of surviving to the end of pregnancy.
Some known causes include:
- Chromosomal abnormalities. Studies show that too little or too many chromosomes in the fetus cause 50% to 60% of all miscarriages. Of these cases about half are caused by Trisomy 21, also referred to as Down’s 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 corpus leteum. After about nine to ten weeks the placenta should be producing enough progesterone to support the pregnancy. Low 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.
- Infections and diseases. Many bacterial and viral infections can contribute to miscarriage, including viral infections such as the cytomegalic virus, bacterial infections such as chlamydia, mycoplsma, urea plasma, and streptococcus, or in rare cases parasitic infections 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 the pregnancies in women over 40 end in miscarriage.
- Other possible causes. Chronic illness, exposure to environmental toxins (such as certain metals0, and stress. Examples include thyroid abnormalities (either overactive or under active thyroid), poorly controlled diabetes mellitus, or intrauterine adhesions (most commonly caused by previous infections or dilation and curettage’s). High dose X-irradiation and chemotherapy re known toxins that can cause pregnancy loss. Industry employees working with chemicals such as dyes, metals, solvents, or chemical production plants 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 anti-bodies such as the lupus anti-coagulant and the anti-cardiopilin anti-bodies can cause miscarriages. These factors are not well understood, and there is no agreed upon effective treatment.
- Women often unnecessarily blame themselves for having a miscarriage. It is important to remember that the fetus probably would not have survived the pregnancy anyway. And keep in mind that having one miscarriage does not necessarily mean having another. The chances are very high that you’ll carry your next baby to full term.
Symptoms & Diagnosis
If you are pregnant and have any of these symptoms, call your health-care provider immediately:
- Vaginal bleeding. Especially heavy bleeding for 24 hours followed by light bleeding that continues for three or more days.
- Abdominal pain. Severe or persistent pain in the lower stomach or back for up to 24 hours.
- 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 t collect the tissue and place it in a clean jar to bring in for medical inspection.
Your health-care provider will listen for a fetal heartbeat and perform a pelvic exam. If a heartbeat is not heard and your cervix is dilated, or widened, or if your membranes have ruptured, then most likely a miscarriage is in progress, or has already happened. This may be termed an inevitable miscarriage. If a fetal heartbeat is detected and your uterus is still enlarged, you may have suffered a threatened miscarriage. In this case, you will have vaginal bleeding but the fetus is still alive. See threatened miscarriage for more information. These may also be symptoms of ectopic pregnancy.
An ultrasound exam may also be administered; those performed transvaginally are the most accurate. This test emits high frequency sound waves that penetrate the uterus to reveal an image of the fetus on a monitor. If no image of the fetus is seen or you can see fetal tissue traveling through the dilated cervix, then you may have had a miscarriage, or are in the process of one. If the fetus looks intact, and your uterus is still enlarged, then you may have suffered threatened miscarriage. Some women do not experience any symptoms. When this happens, the miscarriage may go undetected for several weeks, until the next prenatal visit. If a fetal heartbeat is not heard after eight to ten weeks gestation and there is no sign of uterine growth, then the miscarriage probably took place.
Many miscarriages happen before the woman knows she is pregnant. Miscarriages can be mistaken for periods that are unusually heavy and severe. If you have any concerns about your last period, talk to your health-care provider.
Surgery is not necessary if the fetus placenta are completely expelled from the uterus. Modern management has determined that this may be both a safe and economical approach to a spontaneous miscarriage. But only part of the fetus and placenta are expelled, or none at all, one of two procedures my be suggested:
- D & C (dilation and curettage). The cervix is dilated or widened and a curette is used to scrape 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.
Bleeding may continue for several weeks after miscarriage and change in color from bright red to pink. If you undergo a suction procedure, you may also experience abdominal cramping, nausea, and vomiting.
If the bleeding gets heavier after a few weeks instead of decreasing, contact your health-care provider. If fever develops, or if vaginal discharge has a strange or unpleasant odor, inform your doctor. Avoid intercourse, douching, or using tampons for at least two weeks.
It is difficult to prevent any early miscarriage. If you know you are pregnant, make sure you get proper prenatal care and talk to your health-care provider about such crucial matters like an appropriate diet and the exact nutritional supplements to take.
After a threatened miscarriage, rest in bed for at least a day and avoid intercourse for a few weeks. Most likely you will carry your baby to term. Remember that it’s very normal for women to bleed early pregnancy, and it’s certainly not always an indication that the fetus is unhealthy or you are having a miscarriage. In fact, some women bleed throughout their pregnancy. It should be brought to your health care provider’s attention, as bleeding can be associated with other medical problems such as uterine fibroids, abnormal placenta implantation, and chronic abruptio (relatively rare). Talk to your health care provider about any concerns you have.