The International Council on Infertility Information Dissemination, Inc

Ultrasound -- See Sonogram.

Umbilical Cord -- Two arteries and one vein encased in a gelatinous tube leading from the baby to the placenta. Used to exchange nutrients and oxygen from the mother for waste products from the baby.

Undescended Testicles (Cryptorchidism) -- The failure of the testicles to descend from the abdominal cavity into the scrotum by one year of age. If not repaired by age six, may result in permanent fertility loss.

Unexplained infertility --- Unexplained infertility is a diagnosis of exclusion, once a couple have both been evaluated. The reasons for infertility are unable to be determined. Approximately 10 to 15 percent of couples will receive the diagnosis of unexplained infertility.

Unicornate Uterus -- An abnormality in which the uterus is "one sided" and smaller than usual.

Ureaplasma (similar to Mycoplasma) -- An infection that may cause the formation of sperm antibodies and an inflammation of the uterine lining, either of which may interfere with implantation of the embryo.

Urethra -- The tube that allows urine to pass between the bladder and the outside of the body. In the man this tube also carries semen from the area of the prostate to the outside.

Urinary Tract Infection (UTI) -- Infection of the kidney, ureter, bladder, or urethra. Common symptoms include a frequent urge to urinate and a painful, burning when urinating, but symptoms are not always present.

Urologist -- A physician/surgeon specializing in the urinary tract and male repoductive tract.

Uterus -- The hollow, muscular female reproductive organ that houses and nourishes the fetus during pregnancy. The womb.

UTI -- See Urinary Tract Infection.