I have heard that using precared breastpump is like inviting infection! Is this true? Is it safe to use a precared breastpump?

I haven't really come across anyone yet who has used a precared breastpump. In fact, a lot of my friends have used one, but never a pre-used one. I suggest it better to go for a new one, no matter how well cared for the used one is. With something as precious as your baby and your milk, why to take a risk?