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 (mammals) dogs there's a positive correlation between a longer gestation time and a small litter size. Pregnancy (mammals) In mammals, pregnancy is the period of reproduction during which a female carries one or more live offspring from implantation in the uterus through gestation. It begins when a fertilized zygote implants in the female's uterus, and ends once it leaves the uterus. During copulation, the male inseminates the female. The spermatozoon fertilizes an ovum or various ova in the uterus or fallopian tubes, and this results in one or multiple zygotes. Sometimes, a zygote can be created by humans outside of the