How the contractualist account of preconception negligence undermines prenatal reproductive autonomy

Suppose a physician advises a woman to delay her planned pregnancy for a few months in order to significantly reduce the likelihood that her baby will suffer with Spina Bifida. If the woman chooses to ignore this advice and conceives soon after, I believe most people would consider it a matter of common sense that the child thus born is a victim of this woman's negligence, even if it is fortunate enough to not be burdened with Spina Bifida. This common sense judgement appeared to have been done in by the fact that the timing of conception can be identity-influencing, and so the child that is born only exists because of its mother's decision to ignore her physician's advice. However, recently, contemporary contractualist theories have been used to make sense of preconception negligence towards persons whose existence is a result of that same negligence. I will briefly discuss this interesting development and then show how this retrieval of the common sense judgement comes at a great cost to prenatal reproductive autonomy.