Fetal Aneuploidy

Fetal aneuploidy refers to a condition where a developing baby (fetus) has an abnormal number of chromosomes. Chromosomes are tiny, thread-like structures found inside every cell of our body, carrying all of our genetic information (DNA). Humans typically have 46 chromosomes, arranged in 23 pairs. In aneuploidy, there's either an extra copy of a chromosome (called a trisomy, like in Down syndrome, also known as Trisomy 21) or a missing copy of a chromosome (called a monosomy). These chromosomal imbalances can significantly impact a baby's development and health. Most cases of fetal aneuploidy occur due to a random error during the formation of egg or sperm cells, or shortly after conception. This error, known as 'non-disjunction,' means that chromosomes don't separate properly, resulting in an egg or sperm cell with too many or too few chromosomes. When such a cell is involved in fertilization, the resulting embryo will have an abnormal chromosome count. While these errors are largely spontaneous and can happen in any pregnancy, the risk of aneuploidy generally increases with the mother's age. It's important to understand that in most instances, aneuploidy is not inherited from the parents but is a new event in that specific pregnancy. Lab tests, such as non-invasive prenatal testing (NIPT), chorionic villus sampling (CVS), or amniocentesis, are crucial for detecting fetal aneuploidy. These tests help identify the presence of these chromosomal abnormalities, providing you and your healthcare team with vital information about your baby's health status during pregnancy. Receiving these results allows for informed discussions about potential health challenges, preparation for your baby's birth, and decisions regarding your ongoing medical care and support.