Losing a pregnancy can be heartbreaking. And for many expectant couples, the fear of having a miscarriage can be consuming, even edging out the excitement about being pregnant.
Unfortunately, miscarriages are fairly common. On average, one in five pregnancies will end in a miscarriage - and some research shows that there are up to 800,000 miscarriages a year in the United States.
In most cases, a miscarriage cannot be prevented because it is the result of a random genetic or chromosomal change that occurs during conception or during early fetal development. That said, certain factors - such as age, smoking, drinking, and a history of miscarriage - put a woman at a higher risk for losing a pregnancy. But you can do many things to increase the chances that you and your baby will be healthy throughout the pregnancy.
What Is a Miscarriage?
A miscarriage is the spontaneous abortion of an embryo or fetus before it's developed enough to survive. This can happen even before a woman is aware that she is pregnant.
A miscarriage usually occurs in the first 3 months of pregnancy, before 20 weeks' gestation. A small fraction of miscarriages - less than 1% of them - are called stillbirths, as they occur after 20 weeks of gestation.
Symptoms of a Miscarriage
Many women don't even know that they've had a miscarriage, thinking that it's just a particularly heavy menstrual flow.
Some women experience cramping, spotting, abdominal pain, fever, weakness, vomiting, or back pain. Spotting is not always a sign of a miscarriage; many women normally experience it early on in pregnancy. But just to be safe, if you have spotting or any of these other symptoms anytime during your pregnancy, it's a good idea to talk with your doctor.
If you have had a miscarriage, your doctor may use a number of terms to explain what has happened. Your doctor may say you have a blighted ovum, which is a miscarriage that has occurred so early that no clearly defined fetal tissues have formed. An inevitable miscarriage is bleeding and cramping during the early stages of a pregnancy, signs that the cervix may be opening. An incomplete miscarriage is when the body does not expel all the elements of the pregnancy. A missed miscarriage is when the body does not discharge the fetus, the placenta, or other elements for several weeks - this might occur when the woman has neither menstrual periods nor any signs of pregnancy. A recurrent abortion is when a woman miscarries three or more consecutive times.
A stillbirth, the death of a baby after the 20th week of pregnancy, can occur before delivery or as a result of complications of labor or delivery. It is very rare and occurs in less than 1% of all births. A stillbirth also is sometimes referred to as intrauterine fetal death or antenatal death. There is no way to predict when stillbirth will happen or who will have one, and the cause of about one-third of all stillbirths remains unknown.
The first and most common sign of a stillbirth is lack of movement in the baby as the due date approaches. This might be accompanied by persistent cramping or stabbing pains in the pelvis, back, or lower abdomen, or vaginal bleeding. If you experience any of these symptoms, talk to your doctor.
Your doctor can listen for the fetal heartbeat with a stethoscope, use Doppler ultrasound to detect the heartbeat, or give you an electronic fetal non-stress test, which involves lying on your back with electronic monitors attached to your abdomen. The monitors record the baby's heart rate, movements, and contractions of the uterus.
Why Do Miscarriages and Stillbirths Happen?
The most common cause of pregnancy loss is a random chromosome abnormality that occurs during fertilization. For fertilization to occur, the chromosomes in the nucleus of both the egg and the sperm need to join into 23 pairs (46 total chromosomes). Sometimes this pairing does not happen correctly and that can impede the development of the fetus.
Other factors that could contribute to a miscarriage include:
- fertilization late after ovulation
- low or high levels of the thyroid hormone
- uncontrolled diabetes
- exposure to environmental and workplace hazards, such as radiation or toxic agents
- uterine abnormalities
- incompetent cervix, or when the cervix begins to open (dilate) and thin (efface) before the pregnancy has reached term
- certain medications (mostly prescription), such as the acne drug Accutane
Certain behaviors also increase the risk of a miscarriage. Smoking, for example, puts nicotine and other chemicals into the bloodstream that cause the blood vessels in the placenta to spasm, which decreases the blood flow to the uterus. Smokers also have a lower level of oxygen in their blood, which means the fetus gets less oxygen. Alcohol and illegal drugs have been proved to lead to miscarriages. There is no evidence that stress or sexual activity contributes to miscarriage.
Some of the common causes of a stillbirth include:
- pre-eclampsia and eclampsia, disorders of late pregnancy that involve high blood pressure, fluid retention, and protein in the urine
- uncontrolled diabetes
- abnormalities in the fetus caused by infectious diseases - such as syphilis, toxoplasmosis, German measles, rubella, and influenza - or by bacterial infections like listeriosis
- severe birth defects (responsible for about 20% of stillbirths), including spina bifida
- postmaturity - a condition in which the pregnancy has lasted 41 weeks or longer
- chronic high blood pressure, lupus, heart or thyroid disease
What Will Happen After a Miscarriage or Stillbirth?
If you have miscarried, your doctor will do a pelvic exam and an ultrasound test to confirm the miscarriage. If the uterus is clear of any fetal tissue, then there won't be any more treatment. But if the uterus still contains the fetus or portions of the fetus, the doctor will dilate the cervix to perform a dilation and curettage (D&C) - a scraping of the uterine lining - or a dilation and extraction (D&E) - a suction of the uterus to remove fetal or placental tissue. You may have spotting or mild cramping after these procedures, which are done under local or general anesthesia so there is no immediate pain.
If it is determined that your baby has died in utero after the 20th week, the doctor might decide to induce labor and delivery. After the delivery, the doctor will examine the baby and the placenta to help determine the cause of death if it's still unknown.
If you've had several miscarriages, you may want to be evaluated to see if any anatomic, genetic, or hormonal abnormalities are contributing to the miscarriages.
Can Miscarriages or Stillbirths Be Prevented?
Although miscarriage and stillbirths usually can't be prevented, there are precautions you can take to increase your chances of having a healthy pregnancy:
- Maintain a proper diet loaded with folic acid and calcium.
- Exercise after you've gotten your doctor's OK.
- Avoid drugs and alcohol.
- Avoid deli meats and soft cheeses such as feta and other foods that could carry listeriosis.
- Limit caffeine drinks to no more than 1 to 2 cups a day.
- Stop smoking.
- Talk to your doctor about all medications you're currently taking. Unless your doctor indicates otherwise, many prescription and over-the-counter medicines should be avoided during pregnancy.
- Avoid abdominal trauma.
- Get immunized against communicable disease and know your family medical and genetic history.
If you've had a miscarriage or stillbirth, it's important to take time to grieve. The loss of a baby during or shortly after pregnancy is like the loss of any loved one. Give yourself time to heal emotionally and physically. Some health care providers recommend that women wait 3 months (three menstrual cycles) or more before trying to get pregnant again to give their bodies and psyches time to heal.
Here are some other things that you can do to help get through this difficult time.
- Attend a support group. Ask your doctor about local support groups for women who are expecting again after a loss.
- Find success stories. Other women who have made it through a subsequent pregnancy after having a miscarriage can be a great source of encouragement to you. Your doctor may be able to give you the name of someone to talk with.
- Request frequent prenatal visits. Even if you aren't medically high-risk, ask your doctor if you could schedule prenatal appointments more often for your own peace of mind.
- Be proactive. The more you know about the medical aspects of your pregnancy, the better you'll be able to discuss treatment options and outcomes with your doctor.
- Monitor the baby's movements. If you're far enough along - usually between 18 and 22 weeks, but sometimes not until 28 weeks - to feel kicks and jabs, keep a log of the baby's activities each morning and night and report any abnormalities or lack of movement to your doctor. If your baby isn't moving, eat or drink something sugary and lie down on your side. If you don't feel kicks about 45 minutes after you've consumed the sugary substance, call your doctor immediately.
- Try not to compare. No two pregnancies are exactly alike, so try not to dwell on any similarities between this pregnancy and the one that ended in a loss.
- Stay focused on your goal. You may feel like you've been pregnant forever, but it helps to remember that before long, the pregnancy will be a distant memory. If you didn't believe a good outcome was possible, you wouldn't have made the decision to try again.
Reviewed by: Barbara P. Homeier, MD
Date reviewed: August 2005