6/11/09

Thalassemia and Pregnancy

There is a connection between thalassemia and pregnancy in that the disease is an inherited condition. Parents who either have the disease or are carriers for it can pass thalassemia onto their child. Couples who are concerned about thalassemia and pregnancy can undergo genetic testing or use in vitro fertilization to minimize the chances of having a baby with thalassemia.

Is There a Link Between Thalassemia and Pregnancy?
Thalassemia is a type of inherited blood disorder that can cause anemia. It affects a person's ability to produce hemoglobin, which is the protein in red blood cells that delivers oxygen to all parts of the body.

Approximately 100,000 babies worldwide are born with severe forms of thalassemia each year. However, the condition occurs more frequently in people of Italian, Greek, Middle Eastern, Southern Asian, and African ancestry.

The Thalassemia Gene and Pregnancy
Parents who carry the mutated thalassemia gene can pass the gene on to their children. A child who inherits one mutated gene is considered to be a carrier, also known as thalassemia trait. Most people who have thalassemia trait lead completely normal, healthy lives.

Thalassemia and Pregnancy: What's the Risk?
If two people with beta thalassemia trait (carriers) have a baby, one of three things can happen:

•The baby could receive two normal genes (one from each parent) and have normal blood (1 in 4 chance)
•The baby could receive one normal gene from one parent and one variant gene from the other parent, and have thalassemia trait (2 in 4 chance)
•The baby could receive two thalassemia genes (one from each parent) and have a moderate to severe form of the disease (1 in 4 chance).

Thalassemia and Pregnancy: Genetic Tests
If a women or her spouse has a family history of thalassemia, they may want to consider genetic testing before becoming pregnant. Blood tests and family genetic studies can show whether an individual has thalassemia or is a carrier of thalassemia trait. If both parents are carriers, they may want to consult with a genetic counselor for help in deciding whether to conceive or whether to have a fetus that has tested positive for thalassemia.

Thalassemia and Pregnancy: Prenatal Testing
Prenatal testing for thalassemia can be done when a woman is 11 weeks pregnent using chorionic villi sampling (CVS). CVS involves the removal of a tiny piece of the placenta, which will then be tested. Prenatal testing can also be done with an amniocentesis when a woman is 16 weeks pregnant. In this procedure, a needle is used to take a sample of the fluid surrounding the baby, which will then be tested.

Thalassemia and Pregnancy: Assisted Reproductive Therapy
Assisted reproductive therapy is an option for people who are carriers and who don't want to risk giving birth to a child with thalassemia.

A new technique, pre-implantation genetic diagnosis (PGD), used in conjunction with in vitro fertilization, may enable parents who have thalassemia or who carry the trait to give birth to healthy babies. Embryos created in vitro are tested for the thalassemia gene before being implanted into the mother, allowing only healthy embryos to be selected.