amniocentesis (ăm'nēō'sĕntē`sĭs), diagnostic procedure in which a sample of the amniotic fluid surrounding a fetus is removed from the uterus by means of a fine needle inserted through the abdomen of the pregnant woman (see pregnancy pregnancy, period of time between fertilization of the ovum (conception) and birth , during which mammals carry their developing young in the uterus (see embryo ). The duration of pregnancy in humans is about 280 days, equal to 9 calendar months.
..... Click the link for more information. ). The procedure can be done in a hospital or in a doctor's office. Ultrasound ultrasound or sonography, in medicine, technique that uses sound waves to study and treat hard-to-reach body areas. In scanning with ultrasound, high-frequency sound waves are transmitted to the area of interest and the returning echoes recorded
..... Click the link for more information. is used to determine the location of the fetus during the procedure. Fetal cells in the fluid can be grown in the laboratory and studied to detect the presence of certain genetic disorders (e.g., Down syndrome Down syndrome, congenital disorder characterized by mild to severe mental retardation , slow physical development, and characteristic physical features. Down syndrome affects about 1 in every 730 live births and occurs in all populations equally.
..... Click the link for more information. , Tay-Sachs disease Tay-Sachs disease (tā`-săks`)
..... Click the link for more information. ) or physical abnormalities (e.g., anencephaly, or incomplete development of the brain). The sample also can be examined to determine the gender of the fetus and has been used to preselect the sex of the baby, a practice that, although controversial, is much used in some parts of the world. Amniocentesis cannot be used to detect such defects as congenital heart disease or cleft palate cleft palate, incomplete fusion of bones of the palate. The cleft may be confined to the soft palate at the back of the mouth; it may include the hard palate, or roof of the mouth; or it may extend through the gum and lip, producing a gap in the teeth and a cleft
..... Click the link for more information. .

Amniocentesis is generally recommended when there is a family history of genetic disorders or when the woman is over age 35 and therefore at a higher risk of having a baby with a chromosomal abnormality. The procedure is usually carried out around the 14th or 15th week of pregnancy, when there is sufficient amniotic fluid and abortion abortion, expulsion of the products of conception before the embryo or fetus is viable. Any interruption of human pregnancy prior to the 28th week is known as abortion.
..... Click the link for more information. is still an option. It can also be used in the third trimester (after 30 weeks) when Rh incompatibility (see erythroblastosis fetalis erythroblastosis fetalis (ərĭth'rəblăstō`sĭs)
..... Click the link for more information. ) is suspected, or to determine the status of the fetus in early or late delivery or when there are signs of fetal distress.

See also birth defects birth defects, abnormalities in physical or mental structure or function that are present at birth. They range from minor to seriously deforming or life-threatening. A major defect of some type occurs in approximately 3% of all births.
..... Click the link for more information. ; chorionic villus sampling chorionic villus sampling (CVS) or chorionic villus biopsy (CVB) (kōr'ē-ŏn`ĭk, kôr'–)
..... Click the link for more information. ; embryo biopsy embryo biopsy or preimplantation genetic diagnosis (PGD), diagnostic procedure, used in genetic screening , in which a single cell is removed from an embryo two or three days after it has been conceived through in vitro fertilization .
..... Click the link for more information. .

amniocentesis

Surgical insertion of a hollow needle through the abdominal wall into the uterus of a pregnant female to extract fluid from the amniotic sac for analysis of fluid and fetal cells. This can reveal the fetus's sex (important when sex-linked genetic disease is possible), chromosomal disorders, and other problems. First performed in the 1930s, amniocentesis is generally done under local anesthesia in the 15th–17th week of gestation.

amniocentesis [¦am·nē·ō‚sen′tē·səs]

(medicine)

A procedure during pregnancy by which the abdominal wall and fetal membranes are punctured with a cannula to withdraw amniotic fluid.

amniocentesis (redirected from Amniocentesis-indications for)

amniocentesis

amniocentesis
(redirected from Amniocentesis-indications for)