A new technique called non-invasive prenatal testing (NIPT) has been developed, which can detect a range of genetic and chromosomal diseases, as well as fetal sex earlier, more easily and more reliably. NIPT, therefore, potentially expands the market for sex determination and sex selective abortion. This paper argues that both practices should be prevented by not including fetal sex in prenatal test reports. This is because there is a discrepancy between what parents are concerned with (gender) and what the prenatal test can provide (sex). The paper first presents arguments, which indicate a difference between sex and gender before presenting parental motivations for sex selection and sex determination to show that parents are not concerned with their child's sex chromosomes, or even their genitalia, but the gender role that their child will espouse. That, however, is not something that a prenatal test can provide. We are thus left with a situation in which what parents are told, and what they think they are being told, are two different things. In other words, as the conflation of sex with gender is implicit in the disclosure of fetal sex, it may be more accurate to refer to it as misinformation. This misinformation promotes sexism via gender essentialism, which is neither in the interests of the future child nor society.