Pregnancy is usually an exciting time for expectant parents. But pregnancy doesn't always end with the anticipated baby. In rare cases, a woman (or even a man) believes she is pregnant, only to find out that her symptoms were caused not by pregnancy, but by something else entirely. False pregnancy, clinically termed pseudocyesis, is the belief that you are expecting a baby when you are not really carrying a child. People with pseudocyesis have many, if not all, symptoms of pregnancy -- with the exception of an actual fetus. Some men experience a related phenomenon known as couvade, or sympathetic pregnancy. They will develop many of the same symptoms as their pregnant partners, including weight gain, nausea, and backache.

What Causes False Pregnancy? Only recently have doctors begun to understand the psychological and physical issues that are at the root of pseudocyesis. Although the exact causes still aren't known, doctors suspect that psychological factors may trick the body into "thinking" that it's pregnant. When a woman feels an intense desire to get pregnant, which may be because of infertility, repeat miscarriages, impending menopause, or a desire to get married, her body may produce some pregnancy signs (such as a swollen belly, enlarged breasts, and even the sensation of fetal movement). The woman's brain then misinterprets those signals as pregnancy, and triggers the release of hormones (such as estrogen and prolactin) that lead to actual pregnancy symptoms. Some researchers have suggested that poverty, a lack of education, childhood sexual abuse, or relationship problems might play a role in triggering false pregnancy. Having a false pregnancy is not the same as claiming to be pregnant for a benefit (for example, to profit financially), or having delusions of pregnancy (such as in patients with schizophrenia).