sounds like the plastic is deteriorating. you can also sterilize using steam or in the dishwasher.
do you boil the pump parts and bottles? it could be because of boiling. happened to me before
Yes, uv sterliizer turns bottle yellow but no harmful effect at all. So don't worry too much.
Does anyone know where to find Spectra pump parts to replace? Current ones need to be replaced.
Don't worry too much. It looks ugly but not harmful to your baby.
It's normal after ppsu bottles can last longer.
♥️
KY