Appeals to the moral authority of nature play an important role in ethical discussions about the acceptability of prenatal testing. While opponents consider testing a dangerous violation of the moral inviolable course of nature, defenders see testing as a new step in improving dominion over nature. In this study we explored the meaning of appeals to nature among pregnant women to whom a prenatal screening test was offered and the impact of these appeals on their choices regarding the acceptance of screening. Contrary to theoretical debates we found that appeals to the moral authority of nature do not prevent women from welcoming the possibilities of controlling the outcomes of pregnancy, neither do they provide prima facie justification for (not) intervening in the natural course of events. Both acceptors and decliners believed in an inherent morality in nature that must be respected. They welcome the possibility of knowing more about the health of the fetus and to make their own reproductive decisions. Concerns for the quality of their child's life and for their capacity to assure a good life for their family and disabled child appear to play a central role in the decision regarding the use of screening. Appeals to nature can be interpreted as an attempt to justify beliefs regarding suffering that must be avoided and the impact that family interests may have on the decision. These findings have significant implications for ethical guidance in debates about the acceptability and boundaries of control of offspring characteristics by prenatal testing.