False pregnancy False pregnancy False pregnancy, also known as phantom, hysterical pregnancy, pregnancy scares or pseudocyesis, is the appearance of clinical or subclinical signs and symptoms associated with pregnancy when the person is not actually pregnant. False pregnancy 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
Pregnancy in fish Pregnancy in fish Pregnancy has been traditionally defined as the period during which developing embryos are incubated in the body after egg-sperm union. Although the term often refers to placental mammals, it has also been used in the titles of many international, peer-reviewed, scientific articles on fish, e.g. Consistent with this definition, there are several modes of reproduction in fish, providing different amounts of parental care. In ovoviviparity, there is internal fertilization and the young are born live but there is no placental connection or significant trophic (feeding) interaction; the mother's body maintains gas exchange but the unborn young are