What made you want to look up low-pressure? Please tell us where you read or heard it (including the quote, if possible).
While spaying is traditionally recommended for kitties between 4 and 6 months of age, spaying as young as 8 weeks old is considered safe, according to Cat Channel. Many animal shelters actually spay kitties prior to adopting them out at this age.
This can be difficult to stop, and it is highly recommended that such cats are spayed as part of the treatment. Early spaying In the United States, most cats are spayed between 5 and 8 months of age. Many animal shelters and veterinarians are starting to spay female animals at a younger age, even at 2 months. This early neutering does not affect the growth rate, and there are no appreciable differences in skeletal, physical, or behavioral development between those animals neutered early than those neutered at a more traditional age.