DEAR MAYO CLINIC: I recently had a miscarriage at 14 weeks of pregnancy. I'm a healthy 30-year-old and I don't have any chronic medical problems. I didn't smoke or drink while I was pregnant. I'd like to get pregnant again, but I'm afraid of another miscarriage. Is there any way to tell what caused the first one, and if I'm high-risk for it happening again?

ANSWER: Miscarriages are very difficult, and the emotional impact of having a miscarriage can be significant. Although determining the cause of a miscarriage can be hard, it's very unlikely that it resulted from anything you did. Fortunately, because you are young and healthy, there's no increased risk that you'll have another miscarriage. But give yourself some time to recover. I generally suggest that women wait several months after a miscarriage before attempting to become pregnant again.

In medical terms, a miscarriage is the spontaneous loss of a pregnancy before 20 weeks. Miscarriages are much more common than many people realize. About 10 to 20 percent of known pregnancies end in miscarriage. But the actual number is probably much higher, because many miscarriages occur so early in pregnancy that a woman may not know she's pregnant.

Making a definitive diagnosis of what caused a miscarriage is often difficult. Most miscarriages occur because the fetus isn't developing normally. Problems with the baby's genes or chromosomes are typically the result of errors that occur by chance as the embryo divides and grows, not problems inherited from the parents.

In rare cases, a health condition in the mother may lead to miscarriage. Some disorders that can result in miscarriage include uncontrolled diabetes, thyroid disease, infections, hormonal problems, and problems with the uterus or cervix. But these situations are uncommon. None of the following activities cause miscarriage: lifting, straining, having sex, being in stressful situations or exercising. Be assured that in the vast majority of cases, miscarriages are beyond a mother's control.

Because determining a specific cause can be hard, generally when a woman has one miscarriage, the cause isn't investigated. The good news is that after one miscarriage, your risk of miscarriage is the same as that of a woman who's never had a miscarriage. Only after more than two previous miscarriages does your risk increase. And, although the risk of miscarriage rises as you get older, at age 30 you aren't at increased risk due to age.

That you did nothing to cause the miscarriage and that you're not likely to have another may not do much to ease the emotional impact right now. Miscarriage can be a heart-wrenching loss. Take time to grieve the loss of your pregnancy, and seek help from those who love you. You'll likely never forget your hopes and dreams surrounding this pregnancy but, in time, acceptance may ease your pain.

Give yourself at least three months after this miscarriage before you try to become pregnant again. Talk to your doctor if you have questions or if you feel you're having difficulty coping, particularly if you're feeling profound sadness or depression.

Talking to other women who've experienced pregnancy loss because of a miscarriage can be helpful. Although you may not have heard about many others who had a miscarriage, once you open up to those around you about your situation, you may be surprised to learn how many other people also have gone through it. Talking with them about what you're feeling and hearing their stories may ease some of your grief. Many hospitals and medical centers host support groups for people who've experienced pregnancy loss. If you're interested, talk to your doctor about groups what are available in your area.

Bruce Johnston, M.D., Obstetrics and Gynecology, Mayo Clinic, Rochester, Minn.

Medical Edge from Mayo Clinic is an educational resource and doesn't replace regular medical care.

(c) 2009 Mayo Clinic