Tak Chan presents a hypothetical case where a child affected by trisomy 18 was conceived using in vitro fertilisation , and where the parents requested parentage testing.1 Chan argues that doctors are morally obliged to accede to requests for genetic testing to determine parentage provided that carrying out the test results in a low risk of child abandonment.1Although we also support providing genetic testing to determine parentage in the particular case described by Tak Chan, we are concerned about the implications (...) and practicalities of the proposed ‘risk of abandonment’ test for other parentage determination requests. We offer different arguments for why the parents should be assisted in their request in this particular circumstance.Genetic testing to determine parentage is widely available on a direct-to-consumer basis in many jurisdictions including Australia, and the involvement of a medical practitioner is not necessary to access the test. As Tak Chan points out, ordinarily there are few, if any, medical reasons for determining parentage. In the circumstances where one can envisage a medical reason, for example, to clarify recurrence risk for a genetic disorder in future children, this is generally achievable through specific genetic testing, rather than parentage determination.1 Parentage determination has …. (shrink)