False pregnancy
False pregnancy, phantom pregnancy, or hysterical pregnancy— officially called pseudocyesis in humans and pseudopregnancy in other mammals—is the appearance of clinical or subclinical signs and symptoms associated with pregnancy when the organism is not actually pregnant. Clinically, false pregnancy is most common in veterinary medicine (particularly in dogs and mice). False pregnancy in humans is less common, and may sometimes be purely psychological. It is generally believed that false pregnancy is caused by changes in the endocrine system of the body, leading to the secretion of hormones that cause physical changes similar to those during pregnancy. Some men experience the same illnesses as a woman would experience while pregnant when their partner is pregnant (see Couvade syndrome), possibly caused by pheromones that increase estrogen, prolactin, and cortisol levels.
Signs and symptoms
The symptom of pseudocyesis are similar to the symptoms of true pregnancy and are often hard to distinguish from it. Such natural signs as amenorrhoea, morning sickness, tender breasts, and weight gain may all be present. Many health care professionals can be deceived by the symptoms associated with pseudocyesis. Research shows that 18% of women with pseudocyesis were at one time diagnosed as pregnant by medical professionals.