You should wash your breast pump parts and bottles after each use, and sanitize once a day after they've been washed.

Do you have to sanitize breast pump after each use?

All breast pump parts that come in contact with breast milk, such as bottles, valves and breast shields, should be cleaned after each use. It is not possible to completely sterilize breast pump parts at home, even if you boil them. However, sterilization is not necessary to keep these parts safe and sanitary.

Can I reuse breast pump without washing?

Keep a second set of breast pump parts on hand so you don't have to clean them every time you want to pump. Simply clean your parts (soap and warm water) after each use. And until your baby is 3 months old, you should sanitize them daily.