Does/should it reassure women that in the beginning when we all are X spermatozoons and Y spermatozoons

I don't know :/ 

Actually it is sort of a level playing field, they have done studies that a sperm have different advantages based on whether they are X or Y. 
Y sperm tend to swim faster than X sperm....so if the egg is in the already released odds are it will be a boy. But the X sperm live longer so if the egg has not been released the odds are it will be a girl. 

My information from maybe thirty years ago is that the playing field is not entirely equal... indeed, there are more baby boys born than girls...I think I recall something like 104 boys to each 100 girls?

But the figures even out quite soon, until old age women outnumber men...