It is generally recommended to spay kittens at around 5-6 months of age, rather than 8 weeks. At 8 weeks, kittens are still very young and their reproductive organs are not fully developed. Spaying at this age carries a higher risk of complications, such as retained ovarian tissue and uterine stump pyometra. Additionally, kittens at this age are more susceptible to anesthesia-related risks. Waiting until kittens are 5-6 months of age allows them to mature physically and reduces the risks associated with spaying.
If the shelter you are adopting from has a policy of spaying kittens at 8 weeks, it is important to discuss the risks and benefits with the shelter veterinarian or adoption counselor. You may want to consider adopting a kitten that is closer to 5-6 months of age to reduce the potential for complications.