Genetic Carrier Screening for Cystic Fibrosis, Fragile X Syndrome, Hemoglobinopathies, and Spinal Muscular Atrophy

( Last Updated : June 25, 2021)
Project Line:
Health Technology Review
Project Sub Line:
Rapid Review
Project Number:



1. What are the expectations, experiences, and perspectives on preconception and prenatal genetic carrier testing programs and tests for cystic fibrosis, fragile X syndrome, hemoglobinopathies, and spinal muscular atrophy of adults and their reproductive partners, related family members, and health care providers, in terms of:
• accessing and deciding to undergo or offer testing
• the process of testing, including the communication, interpretation, and use of test results
• affecting people’s reproductive decision-making?

Key Message

• People generally describe wanting access to carrier screening because knowing about the risk of passing along a genetic condition is considered important and supportive of their desires to be prepared. In the context of expanded carrier screening programs, this could mean that an increased number of people would want to access these programs.
• Supporting people who are considering carrier screening can be challenging and is likely to be more involved than simply sharing high-level descriptive information about testing details and potential outcomes. Descriptive information is important to help people understand the screening process and the types of results that could emerge from testing; however, programs might be more supportive of informed decision-making if the providers take a proactive role and are open to facilitating speculative conversations about potential ramifications in people’s actual lives. This is challenging given the expressed desire by health care providers, clinical geneticists in particular, to provide “neutral information” that patients would not experience as prescriptive.
• Given the challenge of supporting people making decisions about whether or not to pursue carrier screening, and the likely increase in people who would consider carrier screening if targeted programs were expanded to population-level screening, it is important to ensure that health care providers are both aware of jurisdictional carrier screening programs and competent in what carrier screening can offer their patients in terms of clinical actionability. Although this is particularly true for general practitioners who are often the primary point of contact with the health care system for their patients, it is also important for people who work in family planning clinics and women’s health clinics.
• Having the option to engage with carrier screening at the preconception stage was universally preferred by participants across the included studies. Compared with prenatal carrier screening, preconception carrier screening was seen as providing prospective parents with more reproductive options. Health care providers were concerned that offering carrier screening during pregnancy might lead pregnant people and their partners to confuse it with other prenatal testing which would limit people’s ability to be truly informed before deciding whether or not to pursue screening. However, if offered as a prenatal option, most people consider it important to do so as early as possible because it could be paired with other prenatal tests. Although not referred to specifically by any of the included studies, we note that offering carrier screening prenatally rather than at preconception, could place the responsibility to make the decision on cisgender women and non-binary or transgender people with uteruses.
• Sequentially designed carrier screening programs were the most common across the included studies; however, people moving through programs with this design found the interim period between receiving their positive carrier results and receiving their partners’ results difficult. This was particularly true for people who were already pregnant because this interim period forced them to reimagine both their relationship with the fetus and the future they had imagined with that child. Of course, this reimagining might be necessary if both partners’ screening results came back positive for the condition in question, but to stagger the return of the results could put undue anxiety on potential parents.
• Carrier screening will not affect everyone in the same way, and reproductive decision-making will still be complex and difficult. As such, the opportunity to engage with genetic counsellors on reproductive options following positive carrier status result is considered valuable.