Pregnant women's perspectives on expanded carrier screening
Propst L, Connor G, Hinton M, Poorvu T, Dungan J. Pregnant women's perspectives on expanded carrier screening [published online February 23, 2018]. J Genet Couns. doi:10.1007/s10897-018-0232-x.
Although several authors have discussed ECS detection rates, less has been reported on how women perceive ECS or how they elect or decline screening. Studies have found that the decision to undergo screening for cystic fibrosis is influenced by factors that include age, sex, ethnicity, socioeconomic status, lack of family history, cost, fear of a blood test, lack of knowledge about the condition, already having children, wanting to avoid having a disabled child, abortion preferences, and feeling pressured by health care providers.6,7 Propst and colleagues asked women for their perspectives on ECS, on electing or declining screening, and on any anxiety associated with their decision.
Details of the study
Women who declined ECS said they did so because they:
- had no family history
- knew there was a very small chance their partner carried the same condition
- would not change the course of their pregnancy on the basis of the test results.
Women who elected ECS said they did so because they wanted to:
- know their risk of having a child with a genetic condition
- have all available information about their genetic risks
- be able to make decisions about continuing or terminating their pregnancy.
Women also were asked what they would do if they discovered their fetus had a genetic disorder. About 42% said they were unsure what they would do, 34% said they would continue their pregnancy and prepare for the birth of an affected child, and 24% said they likely would terminate their pregnancy.
The most common reason women gave for declining ECS was that they had no family history. However, ECS is not a good option for women with a positive family history, as they need genetic counseling and specific consideration of their own risks and what testing should be done. The majority of couples who have a child with a genetic disease have no other family history of the disorder. In a study of reproductive carrier screening in Australia, 88% of carriers had no family history.1 Careful pretest counseling is needed to explain the distinction between, on one hand, genetic counseling and testing for those with a family history of genetic disease and, on the other hand, population screening performed to identify unsuspecting individuals who are healthy carriers of genetic disorders.
Another crucial point about carrier screening is the need to consider how its results will be used, and what options the carrier couple will have. For women who are pregnant when a risk is identified, options include expectant management, with diagnosis after birth, or prenatal diagnosis with termination of an affected fetus, out-adoption of an affected fetus, or expectant management with preparation for caring for an affected child. For women who are not pregnant when they have ECS, additional options include use of a gamete (ovum or sperm) donor to achieve pregnancy, or preimplantation genetic diagnosis with implantation of only unaffected embryos.
WHAT THIS EVIDENCE MEANS FOR PRACTICE
Different pregnant women may have very different preferences regarding genetic testing. Although many are unsure how they would proceed following the diagnosis of a fetal genetic disorder, it is important to carefully explain their options before any testing is done.