fetus in fetu


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fetus

 [fe´tus] (L.)
the developing young in the uterus, specifically the unborn offspring in the postembryonic period, which in humans is from the third month after fertilization until birth. See also embryo. 

The stages of growth of the fetus are fairly well defined. At the end of the first month it has grown beyond microscopic size. After 2 months it is a little over 2.5 cm long, its face is formed, and its limbs are partly formed. By the end of the third month it is 8 cm long and weighs about 30 g; its limbs, fingers, toes, and ears are fully formed, and its sex can be distinguished.

After 4 months the fetus is about 20 cm long and weighs over 200 g. The mother can feel its movements, and usually the health care provider can hear its heartbeat. The eyebrows and eyelashes are formed, and the skin is pink and covered with fine hair called lanugo. By the fifth month the fetus's body is covered with a cheeselike substance (vernix caseosa), which serves to protect it in its watery environment. By the end of the fifth month it is 30 cm long, weighs 450 g, and has hair on its head. At the end of the sixth month it is 35 cm long and weighs 900 g, and its skin is very wrinkled.

After 7 months the fetus is 40 cm long and weighs over 1.3 kg, with more fat under its skin. In the male, the testes have descended into the scrotum. By the end of the eighth month it is 45 cm long, may weigh 2.3 kg, and has a good chance of survival if it is born at that time. At the end of 9 months, the average length of a fetus is 50 cm and the average weight is 3.2 kg. adj., adj fe´tal.
calcified fetus a dead fetus that has become calcified in utero; called also lithopedion.
fetus in fe´tu a small, imperfect fetus, incapable of independent life, contained within the body of another fetus.
harlequin fetus an infant with a severe and dramatic form of congenital ichthyosis, manifested by hyperkeratosis with rigid skin; death usually occurs in the first six weeks of life.
mummified fetus a dead fetus that is dried up and shriveled.
fetus papyra´ceus a dead fetus flattened by being pressed against the uterine wall by a living twin.
parasitic fetus in unequal twins, an incomplete minor fetus attached to a larger, more completely developed fetus (the autosite).

fe·tus in fe·'tu

condition in which a small, imperfectly formed fetus is contained within a fetus.

fetus in fetu

[infē′to̅o̅]
a fetal anomaly in which a small, imperfectly formed twin, incapable of independent existence, is contained within the body of the normal twin, the autosite.

fe·tus in fe·tu

(fe'tŭs fē'tū)
Disorder in which a small, imperfectly formed fetus is contained within another fetus.

fetus

[L.] the developing young in the uterus, specifically the unborn offspring in the postembryonic (see also embryo) period, after major anatomical structures have been outlined.

anomalous fetus
a fetus with one or more congenital defects.
calcified fetus
lithopedion; a fetus that has become calcified.
emphysematous/putrescent fetus
due usually to death of the fetus at parturition; the fetus has been dead for several days, decomposition has occurred and gas has been produced and can be palpated as subcutaneous crepitus; presents a major obstetrical difficulty because of the increased size of the fetus and its extreme dryness due to lack of fetal fluids. The conceptus has a putrid and persistent odor.
fetus in fetu
a small, imperfect fetus, incapable of independent life, contained within the body of another fetus.
mummified fetus
oversized fetus
commonly the result of very good feeding in the last trimester of pregnancy and often the cause of dystocia in beef heifers. See also fetal giantism.
fetus papyraceus
a fetus flattened by being pressed against the uterine wall by a living twin.
parasitic fetus
an incomplete minor fetus attached to a larger, more completely developed fetus, or autosite.