The New 'X' Files?

It has apparently proved possible to separate X and Y human sperm on the basis of their differential movement (https://www.theguardian.com/science/2019/aug/13/sperm-separation-method-may-allow-gender-selection-in-ivf). This might well lead to the technique being used to specify sex in in vitro fertilisation programmes. Although favouring one sex is generally a bad idea (particularly seen in some cultures), there are some genetic conditions where specifying the sex could reduce the risk of passing on harmful conditions.