DMD and congenital adrenal hyperplasia: Determination of fetal sex using non-invasive methods reduces unnecessary further testing or treatment, such as in the instance of a female pregnancy in families at risk of X-linked disorders (e.g. BMD/DMD [30]) (Figure 2), and in cases of congenital adrenal hyperplasia (CAH) where treatment with dexamethasone can be restricted to female fetuses [46,47].