Question
What is a Down syndrome baby? How is it caused?
Answer
A Down syndrome baby, also known as trisomy 21, is a congenital disease caused by an extra chromosome in the 21st pair of chromosomes in a fetus. This condition leads to severe intellectual disabilities and various physical abnormalities, including cardiovascular diseases and growth and development delays. The occurrence of Down syndrome is random, and women without a family history can also give birth to Down syndrome babies. The risk of Down syndrome increases with the age of the mother, particularly in women over 35 years old. Therefore, it is very important for pregnant women to undergo Down syndrome screening. Down syndrome screening is a method that involves taking a pregnant woman’s serum to detect the concentration of alpha-fetoprotein (AFP) and chorionic gonadotropin (hCG), combined with the expected delivery date, age, weight, and gestational age to calculate the risk of the fetus having Down syndrome. It is usually performed between the 15th and 20th week of pregnancy, with results typically available within one week. If the risk assessment shows a high risk, further procedures such as amniocentesis or chorionic villus sampling may be needed for confirmation.