amniocentesis

/am'nee oh sen tee"sis/, n., pl. amniocenteses /-seez/.

a surgical procedure for obtaining a sample of amniotic fluid from the amniotic sac in the uterus of a pregnant woman by inserting a hollow needle through the abdominal wall, used in diagnosing certain genetic defects or possible obstetric complications.

[1955-60; amnio- (as comb. form of AMNION) + CENTESIS]

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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.

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▪ medicine

      the surgical insertion of a hollow needle through the abdominal wall and into the uterus of a pregnant female and the aspiration of fluid from the amniotic sac for analysis. Examination of the amniotic fluid itself as well as the fetal cells found in the fluid can reveal such things as fetal sex (the significant factor in inherited diseases that are sex-linked), chromosomal abnormality, and other types of potential problems. The procedure, generally carried out in the 15th to 17th week of gestation, is relatively painless and can be carried out under local anesthesia.

      Once used only in medical management of erythroblastosis fetalis (a blood disorder of the fetus and newborn that is caused by antibodies in the mother's blood), amniocentesis was first performed in the 1930s. More than 50 metabolic diseases can now be diagnosed by use of the procedure, but it is used most often for the identification of chromosomal anomalies and neural tube defects. It is also often recommended for women 35 years or older and for women who have experienced three or more spontaneous abortions.

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