NEW YORK (GenomeWeb) – Most parents who discover that their child is a recessive disease allele carrier through newborn screening do not use this information to make future reproductive decisions, a new study suggests.
As reported in Genetics in Medicine this week, Canadian researchers surveyed hundreds of women whose infants had undergone carrier screening for cystic fibrosis. Results from dozens of mothers to carriers after testing and again a year later suggested that parents appreciated having information on their child's carrier status, with more than 90 percent of respondents sharing the information with family members.
Even so, the team noted that most parents — around 65 percent — did not plan to alter their family planning strategies based on the test results. In some cases, the parents shared carrier status information with both the affected and unaffected sides of the family.
"Our results suggest that the reproductive benefits of [cystic fibrosis] carrier infants are not uniform or consistent," corresponding author Fiona Miller, a researcher with the University of Toronto's Institute of Health Policy, Management, and Evaluation, and her co-authors wrote, noting that "carrier results were sometimes used in unintended ways: some parents tested their other children and non-carriers informed their relatives that they may be carriers of [cystic fibrosis]."
After reviewing questionnaires from 134 women whose infants had carrier screening for cystic fibrosis, the team focused on 131 women, including 77 who were mothers to cystic fibrosis carriers. In surveys done a year later, 74 women responded, including 57 mothers of carriers.
Some 92 percent of mothers to carriers conveyed this information to family members, and more than half of those women had themselves undergone carrier testing. But at least some of the mothers did not know which family members it was most important to share the test results with, even when their own carrier status was known.
"[S]ome of the mothers 'told everyone' in their families that they may be [cystic fibrosis] carriers without confirming which side was at risk," the study's authors explained. "This may create more carrier testing and use of counseling services than would otherwise be necessary."
Likewise, some were uncertain about whether to share the information with carrier children when they reached adulthood and the majority of parents to carriers did not think the test results would inform their family planning or influence their decision to have more children.
In the small group of mothers of non-carriers, the team found that more than 10 percent still planned to pursue their own carrier testing or had mistakenly told relatives that they could be cystic fibrosis carriers.
Based on findings from that study, the authors suggested that "carrier results should be considered a secondary benefit and thus support previous calls to consider them 'additional' or 'limited secondary' benefits."