aneuploidy
Pronunciation: an-YOO-ploy-dee
Chromosomal abnormality involving an incorrect number of chromosomes in an embryo or gamete.
Full Definition
Aneuploidy refers to the presence of an abnormal number of chromosomes in a cell, typically resulting from errors during meiosis. In reproductive endocrinology, aneuploidy is a major cause of implantation failure, miscarriage, and birth defects. The incidence of aneuploidy increases significantly with maternal age, particularly after age 35. Common aneuploidies include trisomy 21 (Down syndrome), monosomy X (Turner syndrome), and various autosomal trisomies. Preimplantation genetic testing can screen embryos for aneuploidies before transfer, helping to improve pregnancy outcomes in assisted reproductive technology cycles.
Usage
Usage note: Distinguish from other chromosomal abnormalities; specify type when known.
In Context
- "The embryo was diagnosed with aneuploidy following preimplantation genetic screening." — Laboratory report
- "Maternal age significantly increases the risk of aneuploidy in oocytes." — Patient counseling material