Miscarriage is the spontaneous loss of a pregnancy before the 20th week. About 10 to 20 percent of known pregnancies end in miscarriage. But the true number is probably higher since many miscarriages occur so early in pregnancy that a woman does not know she was pregnant.
The term miscarriage is insidious because it possibly suggests that something was done wrong while you were pregnant. This is true only rarely. Most miscarriages occur because the fetus is not developing normally.
Miscarriage is a relatively frequent experience, but that doesn’t make it any easier to cope. To take a step toward emotional healing, learn about the causes of miscarriage, what the reasons are that increase the risks, and what medical attention you may need.
Most miscarriages occur before the 12th week of pregnancy.
Symptoms and signs of miscarriage include the following:
- Vaginal spotting or bleeding
- Pain or cramping in the abdomen or lower back
- Fluids or tissues coming out of the vagina
If fetal tissue has come out of the vagina, place it in a clean container and take it to your health care provider’s office or hospital for testing.
Remember that most women who have vaginal spotting or bleeding during the first trimester continue to have successful pregnancies.
Abnormal genes or chromosomes
Most miscarriages occur because the fetus is not developing normally. About 50% of miscarriages are associated with more or fewer chromosomes. More often, chromosome problems are the result of errors that occur by chance when the embryo divides and grows, not problems that are inherited from the parents.
Chromosomal abnormalities may result in the following:
- An embryonic pregnancy. Embryonic pregnancy occurs when no embryo is formed.
Intrauterine fetal death. In this situation, an embryo forms, but stops developing and dies days before any symptoms of pregnancy loss occur.
- Molar pregnancy and partial molar pregnancy. In the case of molar pregnancy, both groups of chromosomes come from the father. Molar pregnancy is associated with abnormal growth of the placenta. Normally, there is no fetal development.
A partial molar pregnancy occurs when the mother’s chromosomes remain, but the father provides two sets of chromosomes. Generally, a partial molar pregnancy is associated with abnormalities of the placenta and an abnormal fetus.
Molar pregnancy and partial molar pregnancy are not viable pregnancies. Sometimes, they can be associated with cancerous changes in the placenta.
Mother’s Health Conditions
In a few cases, the health condition of the mother could result in a miscarriage. For example:
- Uncontrolled diabetes
- Hormonal problems
- Problems of the uterus or cervix
- Thyroid disease
What DOES NOT cause miscarriages
Routine activities such as those presented below do not cause miscarriages:
- Engage in physical activity, including high-intensity activities such as jogging and bicycling.
- Having sex.
- Work, as long as you are not exposed to harmful chemicals or radiation. Talk to your doctor if you are concerned about work-related risks.
Several factors increase your risk of miscarriage, including the following:
- Women over age 35 have a higher risk of miscarriage than younger women. At age 35, you are about 20% at risk. At age 40, the risk is about 40%. And, at age 45, it’s about 80%.
- Previous miscarriages. Women who have had two or more consecutive miscarriages are at greater risk of miscarriage.
Chronic conditions. Women with a chronic condition, such as uncontrolled diabetes, have a higher risk of miscarriage.
- Problems of the uterus or cervix. Certain abnormalities in the uterus or weak tissues in the cervix (cervix failure) may increase the risk of miscarriage.
- Smoking and using alcohol and illegal drugs. Women who smoke during pregnancy have a higher risk of miscarriage than women who do not smoke. Alcohol abuse and illegal drug use also increase the risk of miscarriage.
- The weight. Being underweight or overweight are also factors that have been linked to an increased risk of miscarriage.
Invasive prenatal studies. Some invasive prenatal genetic studies, such as chorionic villus analysis and amniocentesis, carry a small risk of miscarriage.
Some women who have a miscarriage have a uterine infection, also called a septic abortion. The signs and symptoms of this infection include the following:
- Tenderness in the lower abdomen
- Foul-smelling vaginal discharge
Often, there is nothing you can do to prevent a miscarriage. Just focus on the proper care of yourself and your baby:
- Attend regular prenatal care visits.
- Avoid known risk factors for miscarriage such as smoking, drinking alcohol, and using illegal drugs.
Take a daily multivitamin.
- Limits caffeine intake. A recent study found that drinking more than two caffeinated drinks per day seemed to be associated with an increased risk of miscarriage.
If you have a chronic condition, work with your health care team to manage it.