Re: Help from moms who use the Medela PIS Advanced!
Change the membranes, yes, but also consider that you breast may have changed over the last few months and your shield size may need to be adjusted, too.
I don't think there is a set time to change out membranes, it really depends on how long and often you pump. I only went through 3 sets in my 9+ months of pumping but some moms change them out way more often than that. Sometimes they will get small tears around the edges, but that isn't always the case.
My little man was born 12/17/2010.
Baby girl was born 4/30/2014.