amniocentesis
Pronunciation: am-nee-oh-sen-TEE-sis
Diagnostic procedure involving needle aspiration of amniotic fluid to test for fetal genetic abnormalities, typically performed between 15-20 weeks of pregnancy.
Full Definition
Amniocentesis is an invasive prenatal diagnostic test where a thin needle is inserted through the maternal abdomen and uterus to extract a small amount of amniotic fluid surrounding the fetus. The fluid contains fetal cells that can be analyzed for chromosomal abnormalities, neural tube defects, and genetic disorders. The procedure carries a small risk of miscarriage but provides definitive diagnostic information about fetal genetic status, unlike screening tests which only assess risk.
Usage
Usage note: Always lowercase unless beginning a sentence; not abbreviated in formal medical writing.
In Context
- "Amniocentesis confirmed the presence of trisomy 21 in the fetus." — Genetic counseling report
- "The patient declined amniocentesis after weighing the risks and benefits." — Clinical documentation