Reducing babies oxygen intake
This is an interesting study where 34 babies were given reduced oxygen for an average of 6.9 hours by only giving them 15% oxygen in the air they breathe rather than the normal 20%.In 4 infants exposure to hypoxic conditions was ended early because of prolonged and severe falls in oxygen saturation.
Now this is what is called a "non-theraputic" intervention. That is something is done to the babies which is not to improve their health. That something is to reduce the amount of oxygen they breathe.
This sounds a very odd thing for anyone to agree to for their 3 month old child.
In particular (see above italics) it caused material problems for about 10% of the babies.