Pseudocyesis

Pseudocyesis, sometimes called false pregnancy, is a rare condition in which a person who is not actually pregnant nonetheless develops many of the recognizable physical signs and symptoms of pregnancy, including abdominal swelling and enlargement, cessation of menstrual periods, breast changes, perceived fetal movement, and in some documented cases even labor-like pains at the expected time of delivery, together with a firm and sincerely held belief on the person's part that they are pregnant. Cases resembling pseudocyesis have been documented since antiquity, with early descriptions attributed even to the ancient physician Hippocrates, and the condition, or presentations very similar to it, has also been observed in some other mammal species. Modern medical understanding holds that pseudocyesis is not simply a delusion invented from nothing, since genuine neuroendocrine and hormonal changes appear to occur in the body, likely triggered by an intense psychological desire for pregnancy or, in some cases, an intense fear of it, producing physical symptoms that can closely mimic true pregnancy. This distinguishes pseudocyesis from a pure delusion of pregnancy, since an affected person will typically accept that they are not pregnant once shown clear objective medical evidence, such as an ultrasound scan, whereas a true delusional belief would tend to persist regardless of such disconfirming evidence.