Pregnancy and Miscarriage
According to the March of Dimes, as many as 50% of all pregnancies end in miscarriage -- most often before a woman misses a menstrual period or even knows she is pregnant. About 15% of recognized pregnancies will end in a miscarriage.
More than 80% of miscarriages occur within the first three months of pregnancy. They are less likely to occur after 20 weeks' gestation; if they do, they are called late miscarriages.
What Are the Symptoms of Miscarriage?
Symptoms of a miscarriage include:
- Bleeding that progresses from light to heavy
- Abdominal pain
- Passing of tissue
If you're pregnant and experience the symptoms listed above, contact your obstetric health care provider right away. He or she will tell you to come in to the office or go to the emergency room.
What Causes Miscarriage?
The medical term for a miscarriage is spontaneous abortion, but the condition is not an abortion in the common definition of that term.
The causes of miscarriage are not well understood. Most of the miscarriages that occur in the first trimester of pregnancy are caused by chromosomal abnormalities in the baby. Chromosomes are tiny structures inside the cells of the body which carry many genes. Genes determine all of a person's physical attributes, such as sex, hair and eye color, and blood type. Most chromosomal problems occur by chance and are not related to the mother's or father's health.
Miscarriages are also caused by a variety of other factors, including:
- Exposure to environmental and workplace hazards, such as high levels of radiation or toxic agents
- Hormonal problems
- Uterine abnormalities
- Incompetent cervix (the cervix begins to widen and open too early, in the middle of pregnancy, without signs of pain or labor)
- Lifestyle factors, such as smoking, drinking alcohol, or using illegal drugs
- Disorders of the immune system, including lupus
- Severe kidney disease
- Congenital heart disease
- Diabetes that is not controlled
- Thyroid disease
- Certain medications, such as the acne drug Accutane
- Severe malnutrition
In addition, women may be at increased risk for miscarriage as they age. Studies show that the risk of miscarriage is 12% to 15% for women in their 20s, and rises to about 25% for women at age 40. The increased incidence of chromosomal abnormalities contributes to the age-related risk of miscarriage.
Note: There is no proof that stress or physical or sexual activity causes miscarriage.
Sometimes, treatment of a mother's chronic illness can improve the chances for a successful pregnancy.
How Is a Miscarriage Diagnosed and Treated?
Your health care provider will perform a pelvic exam and an ultrasound test to confirm the miscarriage. If the miscarriage is complete and the uterus is clear, then no further treatment is usually required. Occasionally, the uterus is not completely emptied, so a dilation and curettage (D&C) procedure is performed. During this procedure, the cervix is dilated and any remaining fetal or placental tissue is gently removed from the uterus. As an alternative to a D&C, certain medications can be given to cause your body to expel the contents in the uterus. This option may be more ideal in someone who wants to avoid surgery and whose condition is otherwise stable.
If a miscarriage was not confirmed, but you had symptoms of a miscarriage, bed rest is often prescribed for several days, and you may be admitted to the hospital overnight for observation. Blood work to determine the amount of a pregnancy hormone (hCG) may be performed to monitor the pregnancy. When the bleeding stops, usually you will be able to continue with your normal activities. If the cervix is dilated, you may be diagnosed with an incompetent cervix and a procedure to close the cervix (called cerclage) may be performed. If your blood type is Rh negative and your partner is Rh positive, your doctor may give you a blood product called Rh immune globulin (Rhogam). This prevents you from developing antibodies that could harm your baby now or in future pregnancies.
Blood tests, genetic tests, or medication may be necessary if a woman has more than two miscarriages in a row (called repeated miscarriage). Some diagnostic procedures used to evaluate the cause of repeated miscarriage include:
- Endometrial biopsy, a procedure involving the removal of a small amount of tissue from the lining of the uterus for study under a microscope Hysterosalpingogram, an X-ray of the uterus and fallopian tubes
- Hysteroscopy, a test in which the doctor views the inside of the uterus with a thin, telescope-like device inserted through the vagina and cervix
- Laparoscopy, a surgical procedure in which the doctor views the pelvic organs with a lighted device
How Do I Know if I Had a Miscarriage?
Spotting and mild discomfort are common symptoms after a miscarriage. If you have heavy bleeding, fever, chills or pain, contact your health care provider right away. These may be signs of an infection.
Can I Get Pregnant Following a Miscarriage?
Yes. At least 85% of women who have miscarriages have subsequent normal pregnancies and births. Having a miscarriage does not necessarily mean you have a fertility problem. On the other hand, about 1%-2% of women may have repeated miscarriages (three or more). Some researchers believe this is related to an autoimmune response.
If you've had two miscarriages in a row, you should stop trying to conceive, use a form of birth control and ask your health care provider to perform diagnostic tests to determine the cause of the miscarriages.
When Can I Try to Get Pregnant After a Miscarriage?
Discuss the timing of your next pregnancy with your health care provider. Some health care providers recommend waiting a certain amount of time (from one menstrual cycle to 3 months) before trying to conceive again. To prevent another miscarriage, your health care provider may recommend treatment with progesterone, a hormone needed for implantation in the uterus.
Taking time to heal both physically and emotionally after a miscarriage is important. Above all, don't blame yourself for the miscarriage. Counseling is available to help you cope with your loss. Pregnancy loss support groups may also be a valuable resource to you and your partner. Ask your health care provider for more information about these resources.
Can a Miscarriage Be Prevented?
Usually a miscarriage cannot be prevented and often occurs because the pregnancy is not normal. However, if the problem is related to the woman's cervix, such as an incompetent cervix, surgical treatments may help.