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Why is carrier testing offered to some couples with a family history of cystic fibrosis?

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Carrier testing is offered to couples with a family history of cystic fibrosis to determine with greater accuracy whether one or both prospective parents are carriers of the recessive trait. Because cystic fibrosis is not expressed unless both members of a homologous chromosome pair carry the mutation, identifying carrier status is essential for assessing the risk of having an affected child.1234

This testing provides prospective parents with accurate information to make informed family-planning decisions. When a family history suggests an increased risk, such as having a sibling with the disorder, molecular testing allows couples to understand their options, which may include:2

Accepting the risks and proceeding with natural reproduction.1
Utilizing donor sperm or eggs.1
Pursuing in vitro fertilization with preimplantation diagnostics to select unaffected embryos.1
Pursuing prenatal diagnosis with the option of selective termination.1
Deciding against biological reproduction.1

Genetic counselors play a vital role in this process, helping couples interpret these risks and navigate the available choices.124