Definition

Noun: 1. A medical procedure during pregnancy: A diagnostic test in which a small amount of amniotic fluid is extracted from the amniotic sac surrounding a developing fetus. This fluid contains fetal cells and chemicals that can be analyzed to detect certain genetic, chromosomal, and developmental abnormalities.

Usage

• Primary Context: The term is used almost exclusively in medical and prenatal care contexts to refer to the specific diagnostic procedure.
• Typical Use: It is discussed as an option for pregnant individuals, often following other screening tests that indicate a potential risk.

Examples

• Noun:
  • The doctor recommended amniocentesis to check for Down syndrome.
  • Amniocentesis is usually performed between the 15th and 20th weeks of pregnancy.
  • The results of the amniocentesis provided reassurance about the baby's health.

Advanced Usage

• "to have an amniocentesis" / "to undergo amniocentesis": These are the standard verb collocations for describing the experience of the procedure from the patient's perspective.
  • She decided to have an amniocentesis after her first-trimester screening showed an increased risk.
  • The patient underwent amniocentesis last Thursday.

Variants and Related Words

• Amniotic fluid (n): The protective liquid contained within the amniotic sac.
• Centesis (n, medical): A general term for a surgical puncture or aspiration of fluid.
• Chorionic villus sampling (CVS) (n): A different prenatal diagnostic procedure that samples tissue from the placenta, often performed earlier in pregnancy than amniocentesis.

Synonyms

• Amnio (n, informal): A common colloquial shortening of the term.
  • She's getting an amnio next week.
• Prenatal diagnostic test: A broader descriptive term.

Notes on Meaning

• Diagnostic vs. Screening: It is critical to distinguish amniocentesis (a test that provides a definitive diagnosis for specific conditions) from tests (like blood tests or ultrasounds, which only assess risk).
• Procedure Focus: The core meaning of the word is the procedure itself. While the goal is to obtain information, the word does not refer to the results or the analysis of the fluid.

Noun

1. (pregnancy) extraction by centesis of amniotic fluid from a pregnant woman (after the 15th week of pregnancy) to aid in the diagnosis of fetal abnormalities