K.M.
I have used the medela bottles for two babies and they are still fine. I did put them in the dishwasher with the second and never had a problem. I also discovered that the medela are a standard size and I got some cheap gerber bottles to use with the pump. The only problem I had is that these bottles don't come with a disk to seal off the hole for the nipple. I got creative to solve this. I used the disks that came with the dr. brown's bottle to seal them. It worked great as long as I made sure that they were on tight. You can even pump directly into the Dr. Brown's Bottles but you have to include the tube thing in it to get it to seal and that made them too big for the medela cooler.