In procedures such as in vitro fertilization (IVF) embryos are created in a laboratory and then transferred to the woman’s uterus. For some couples, especially those at risk for genetic disease, questions arise about the chromosomal make-up of those embryos. A technique called preimplantation genetic diagnosis (PGD) can provide information about some of those abnormalities.
All healthy humans are born with 46 chromosomes that are part of every cell in the body. Chromosomes are divided into 22 matching pairs and one pair of sex chromosomes. These cell structures each carry the genetic material, or DNA, that makes every individual unique. You receive genes from both of your biological parents; half from your mother and half from your father. The genes determine which features you inherit, such as hair and eye color, blood type, and other characteristics — like your father’s nose or your mother’s mouth.
You also inherit, via genes, the risk of developing certain diseases. Hemophilia and Tay-Sachs disease for example, are inherited diseases that can be passed on from parents to children. These diseases are due to defects in the chromosomes.
You may be aware of amniocentesis and chorionic villus sampling (CVS), genetic tests that can be performed while you are pregnant and can determine the baby’s health and sex. If, however, you are having problems getting pregnant or have a history of miscarriages, there is a test you can take before you get pregnant to see if your infertility problems are due to a genetic defect. Genetic problems in the embryo or fetus are responsible for a high percentage of pregnancy losses before 12 weeks