Pregnancy is a condition of female adults in which a fetus or embryo is carried inside the body cavity called a uterus. When a human woman is pregnant, then for a period of time, the embryo or fetus grows to the point where it is born by emerging out of the uterus and becoming a living baby. In humans, the gestation period is roughly nine months, although it can vary depending on circumstances. In most species, pregnancy happens as a result of sexual intercourse between an adult male and adult female, in which a sperm cell and ovum are joined to form a zygote, which may develop into an embryo. Not every act of sexual intercourse results in pregnancy. A normal human pregnancy is approximately 40 weeks and is divided into trimesters.
In Greek mythology
In Greek mythology, gods and goddesses who were immortal could mate with humans; for example, the goddess Athena was born out of the head of Zeus, according to myths as described in works such as the Iliad, Odyssey, and Aeneid. Any sexual relation between a god or goddess with a human always resulted in pregnancy.