A stillbirth is the death of a baby after the 20th week of pregnancy but prior to delivery. If the fetus dies before 20 weeks, it's considered a miscarriage. Stillbirth and miscarriage have different causes and therefore require different methods to evaluate the cause.

Having a stillbirth is obviously a very stressful event, and unfortunately not that rare. About one in 150 births is a stillbirth, accounting for around 20,000 babies per year in the United States. Most stillbirths are detected before labor; it's rare for one to be diagnosed after a baby is born.

Because many stillbirths occur in what appear to be normal pregnancies, the parents are rarely prepared for this devastating outcome, and they commonly ask, "Why did my baby die?" Sometimes the answer is obvious, but often it isn't. But even if no specific cause is found for the baby's death, it's rarely related to anything the parents did.

"Will it happen again?" is another frequent question, and the answer is important because it may help parents deal emotionally with their loss. Knowledge can be empowering, and can provide comfort by helping to alleviate uncertainty or guilt. (Most hospitals have bereavement counselors who can help you sort out some of the questions, and many can refer you to support groups).

After a stillbirth, the first step is to carefully and thoroughly examine the baby and placenta. The doctors will check to see whether there are any malformations, and parents may be asked to consent to an autopsy and other studies. Sometimes it takes several months to get the results of these exams, and the wait can be frustrating. In addition, the doctor will review medical records and the circumstances surrounding the stillbirth for possible causes. During which week of the pregnancy did it happen? Were there other medical problems? What was the baby's weight and was it appropriate for age?
      
After all of the medical information is compiled, you should meet with your doctor and discuss what happened. The best time to do this is two or three months after the delivery, because by that time most of the test results will be in. It's normal to feel uncomfortable discussing a stillbirth with your doctor, and even some doctors may feel uncomfortable because this is such a painful event.
      
Some couples choose to meet with another doctor, too, for an objective assessment of what happened. For this second opinion, I usually suggest that they see an obstetrician who specializes in high-risk pregnancies (a maternal-fetal medicine specialist). Make sure to take your chart and any other information you have so you can answer all of the doctor's questions.
      
In 50 percent of stillbirth cases, a cause, or at least a contributing factor, is identified once all of the test results are in.

The three major causes of stillbirths are:

1. Problems with the placenta and/or umbilical cord:
   The fetus gets its blood, oxygen and nutrients through the placenta and umbilical cord. Because both are lifelines, problems in either one will interfere with fetal development. When the fetus doesn't get enough nutrients, it can develop a form of malnutrition. In a condition called placental insufficiency, this happens over a period of time; in the case of abruptio placentae, it happens suddenly when the placenta detaches from the uterus.
2. Maternal medical conditions and lifestyle choices:
   Certain illnesses in the mother, or their treatments, sometimes cause stillbirths. They include, but aren't limited to, high blood pressure, preeclampsia, diabetes, lupus and heart or thyroid disease. Older mothers are usually at increased risk for these conditions, as well as for stillbirths. Smoking, drinking alcohol and using certain recreational drugs, particularly cocaine, are also associated with higher rates of stillbirth.
3. Birth defects:
   Birth defects are a common but often overlooked cause. In about one-fourth of stillborn babies, one or more birth defects are responsible for the death. Such defects are not always easily found, and often surface only after a thorough examination of the baby and an autopsy.

If the stillbirth was caused by a malformation such as a chromosomal problem or it was due to an umbilical-cord problem, the chances of recurrence are minimal. If the cause was a chronic maternal illness or a genetic disorder, the risk is somewhat higher. On average, the chance that a woman's next pregnancy will result in stillbirth is about 3 percent, which means that the vast majority of post-stillbirth pregnancies are successful.

Once you've determined the cause of the stillbirth, if possible, how long should you wait to get pregnant again?
First, it's important that you grieve your baby's loss. You may feel a strong sense of sadness, anger or bitterness at the unfairness of this tragedy. Although there's generally nothing you could have done to prevent a stillbirth, you may still feel guilt and blame yourself for the death of your baby. You may also have feelings of loneliness and helplessness, or, because of the intensity of your emotions, confusion.
      
Grieving is a process of finding meaning in the loss of your baby. It's a long, unpredictable process and requires a lot of energy. You and other family members need time to grieve, because it's necessary to work through the pain toward healing.
      
How long you wait to have another child depends on your physical and emotional condition. Some couples need more time for mourning, while others may want to try getting pregnant right away. Consult with your doctor before trying again. Some studies have shown that women who choose to conceive sooner may be intrinsically more vulnerable to depression and anxiety than those who wait for at least one year. But keep in mind that despite the emotional and physical trauma of stillbirth, most women who get pregnant again have healthy babies the next time around.