Great point. The low oxygen levels of the mother from wearing masks must be taken into account.
Also, the distress, and perhaps nutrition deficiencies the mother may have encountered through the past year too.
High CO2 is probably worse than low O2 ... but a mask gives you both so...
After reading the comments here I retract my remark on social interactions. Newborns probably do get a lot, normally, with all the fuss from family and friends.
And in that respect lockdowns and face masks would create a big deficit. Especially if mommy and daddy won’t even show their faces.
Twilight Zone for your first three months could really do a number on you.