Cyesis Health Dictionary

n. the period during which a woman carries a developing fetus, normally in the uterus (compare ectopic pregnancy). Pregnancy lasts for approximately 266 days, from *conception until the baby is born, or 280 days from the first day of the last menstrual period (see Naegele rule). During pregnancy menstruation is absent, there may be a great increase in appetite, and the breasts increase in size; the woman may also experience *morning sickness. These and other changes are brought about by a hormone (*progesterone) produced at first by the ovary and later by the *placenta. Definite evidence of pregnancy is provided by various *pregnancy tests, by the detection of the heartbeat of the fetus, and by ultrasound. Medical name: cyesis. See also pseudocyesis. —pregnant adj.... pregnancy