ultrasound
A procedure that uses sound waves to create a moving image of internal organs, used to diagnosis infertility as well as other problems. During pregnancy, ultrasound is routinely used to monitor the health and development of the fetus.
umbilical cord
A cord of tissue connecting the fetus to the placenta that carries oxygen and nutrients to the fetus and transports waste products away. At birth, an umbilical cord, which contains two arteries and one large vein, can be as long as 4 feet.
umbilical hernia
A protrusion of part of the intestine through a defect in the abdominal wall around the belly button, usually manifested as a small bulge. Usually not serious and requiring no medical treatment.
undescended testicles
When one or both of the testes don't descend into the scrotum. Many times the condition corrects itself; other cases need to be surgically corrected so as not to lead to infertility or testicular cancer.
universal birth number
An identification number assigned to a newborn by a state's office of vital statistics. Includes the date of birth, the area code of the birth site, and a registration number.
uterus
The hollow, pear-shaped organ in which a baby grows. During pregnancy, the fist-sized uterus goes from weighing about 2 ounces to weighing about 2.5 pounds and holding a baby.
