If either you or your partner has a high risk indicator such as having a family member who is a carrier or has an inherited genetic disorder like Huntington's chorea, Haemophilia, or Sickle-cell anaemia, you will be asked if you wish to undergo tests such as an ultrasound (usually part of routine prenatal care), chorionic villus sampling, or amniocentesis. While the process of chromosomal disorder testing can cause a lot of anxiety, some couples find that the benefits of early detection outweigh the cons. Whether or not you decide to be tested is absolutely your choice.
Your obstetrician should give you the opportunity to discuss the pros and cons of the testing before you decide. It helps to make a list of all the questions you want to ask. It is easy to forget them once arrive for the testing.