Miscarriage refers to the premature end of a pregnancy before the developing baby is able to survive outside the womb. Miscarriage can occur during the first or second trimester, before 20 weeks. Most occur in the first 12 weeks of pregnancy and most miscarriages are unexpected and isolated events. About 15%-20% of recognized pregnancies end this way.
Some miscarriages cannot be explained. Miscarriages often occur for the following reasons:
- Chromosomal abnormality (advancing maternal age)
- Uterine defects
- Scar tissue from a past surgery
- Insufficient progesterone (a female hormone needed to support pregnancy)
- Infection in the genital tract
- Immunologic factors that may cause blood-clotting problems or rejection of the fetus
A risk factor is something that increases your chance of getting a disease or condition. Risk factors include:
- Advancing maternal age
- Drinking alcohol at a level beyond two drinks per day
- Using illicit drugs (street drugs)
- Exposure to certain environmental toxins
- Infection, such as cytomegalovirus (CMV) and HIV
- Chronic maternal illness, eg, autoimmune diseases, such as lupus and insulin-dependent diabetes with uncontrolled blood sugar
After one miscarriage early in the pregnancy, you are not at increased risk for subsequent miscarriages. If you've had multiple miscarriages (at least three), you may benefit from a medical evaluation to determine the cause.
While miscarriage usually is a one-time occurrence, up to one in twenty couples experience two miscarriages in a row, and one in one hundred have three or more. In some cases, these couples have an underlying problem that is causing the losses. Couples who have experienced two or more miscarriages should have a complete medical evaluation to learn the cause of the miscarriages, and how they can prevent another one. Testing can reveal the cause of repeat miscarriages in at least 75 percent of couples.
- Chromosome problem in one member of the couple in 5 %
- Uterine abnormalities in 10%-15%
- Hormone problems in 5%-40%
- Immune system problems in 5&-10%
- Unknown causes in 25%
Symptoms include some or all of the following:
- Vaginal bleeding
- Pink or brown discharge
- Discharge of the products of conception
You will be asked about your symptoms, the length of your pregnancy, and when you first noticed a change in your condition. The doctor will perform physical and pelvic exams.
Tests may include:
Ultrasound Testing–to assess the health of the fetus or detect an ectopic pregnancy (a pregnancy in which development occurs outside the uterus)
Tissue Examination–to examine tissue that has been expelled and check for chromosome defects
Other tests check the degree of blood loss and for fetal and maternal blood types:
Blood Tests–to check for a chromosomal error in the man or the woman or to check hormone and antibody levels; and to check the exact amount of the pregnancy hormone (quantitative beta-HCG).
Imaging Tests–x-rays or an ultrasound to identify a problem with your uterus
Endometrial Biopsy–reveals the suitability of your uterine lining to accept and sustain an embryo
Hysteroscopy–looking inside your uterus, using a thin, lighted fiberoptic instrument. The hysteroscope is inserted in your vagina and passed through your cervix. The doctor can check for problems with the shape or size of your uterus, and examine and sample the endometrial lining. During the procedure, the doctor also may be able to correct a uterine problem.
Immediate care usually involves observation only, especially in early or first trimester miscarriages. Medication may be indicated in the event of heavy bleeding or cramping. A dilation and evacuation (D&E) may be needed if all uterine contents are not spontaneously expelled. During a D&E, the doctor dilates the cervix, inserts a tool into the uterus, and suctions out remaining material. Women may need professional counseling to recover emotionally from the loss.
The goal of long-term treatment is to prevent future miscarriages. This is geared toward whatever caused past losses.
Medications to decrease the chance of miscarriage may include:
- Antibiotics for infection
- Progesterone supplements (if this hormone is believed to be suboptimal)
- Aspirin and other medications to treat blood-clotting problems caused by immunologic disorders
Many physical abnormalities can be corrected to decrease the chance of another miscarriage. If the cervix is weak, the doctor can place a stitch ('cerclage'), usually at the beginning of the second trimester of the next pregnancy, to keep it closed until you are ready to deliver. If fibroids are a contributing factor, removing them may prevent another loss.
Talking with a professional counselor often helps women deal with their loss. Some people benefit from participating in a support group.
Before you start to plan your next pregnancy consider the following regarding your health:
- Is your diet ready to support another pregnancy?
- Are there habits you should change prior to another pregnancy?
- What medications are you taking and will they affect a pregnancy?
- How is your health?
- Are there issues you should resolve before trying another pregnancy?
- Seek help to learn about your risks and what you can do to minimize them.