I used it for 3 weeks or so. I found that the air return valve worked inconsistently, so the bottle sometimes developed a vacuum which made it harder and harder for DS to suck any milk out. I tried not having the lid on too tight, un'locking' the other tube, having to bottle at different heights compared to my nipple... This was the main reason we stopped - I had to constantly attend to the bottle, which made it hard to relax. And I know (front the weighing) that my milk supply did not change when we stopped using it.

I also found that the micropore tape started to take a few skin cells off every time I removed it, which led to raw skin. I also am struggling with eczematous rash on my breast around my areola, probably from the regular dampness of pumping, and if I used my eczema ointment on it, the tape wouldn't stick! All together too much fuss for too little benefit for us.

When we went back to the bottle, DP's attachment to my breast didn't deteriorate, as it had when we first introduced the calma bottle, so I was happy enough to stick with the bottle at that point.