The general public was uninformed about the meanings of the results of the tests, and many perfectly healthy carriers were led to believe that they were sick. In addition to this, many carriers were denied health insurance coverage. In some cases, state legislatures even passed laws mandating the testing of children for the defective gene before school enrollment. Although this does not qualify as an example of preimplantation genetic diagnosis, the results may foreshadow similar consequences that could arise from this procedure. There is a margin of error in preimplantation genetic diagnosis, as exists with all genetic testing.
Excessive testing has the possibility to do harm, causing parents to worry unnecessarily.
One study examined the effects on families whose children initially tested positive for cystic fibrosis and later proved to be healthy. Despite proof of the misdiagnoses, one-fifth of the parents continued to worry that their children had the disease. Even a majority of physicians have displayed a willingness to violate patient confidentiality and inform relatives at risk in the case of genetic diseases such as Huntington's. Insurance companies contend that they need this information to set fair rates for all policyholders. At this point in time, the aims of preimplantation genetic testing remain, for the most part, admirable.