The first 3 days of our test were miserable. She seemed more agitated than normal, the feedings were longer as she struggled to take the formula down. She was still spitting up massive amounts of chunky fluid during and after each feeding - so much so that I was worried she wasn't keeping anything down.
And then one night my husband went to prepare a bottle in the kitchen. "When you put the water in here do you measure it on the side of the liner? Or the side of the bottle?" he asked.
(Now since day one we have been using Playtex drop-ins, per the advice our our lactation consultant. We have also used the Playtex Vent-Air bottles because I thought they looked cool, and happen to get a free one somewhere. Since we started using the formula though we have used the Drop-Ins solely as they are 8 ounces to the Vent-Airs 6, and were easy to mix the powder formula in. As for the actual liners, we have used Playtex brand, Target and most recent the generic brand at Rite-Aid that specifically say on the box "Use with Playtex Drop-In Bottles") Cut back to the conversation the other night...
"I use the numbers on the side of the bottle...and fill it up to the 6 with 3 scoops of formula...why do you ask?" I enquired.
"Because there are measurements on the side of the liners too, and they don't match up to the ones on the bottle," he said.
I rushed in to the kitchen (because I was baffled) and we did an experiment. We poured 6 ounces of bottled water into the Vent-Air bottles and then poured it back into the Drop-In bottles. What was 6 ounces of water in the Vent-Air was actually at the 8 ounce mark on the side of the Drop-In Bottle!!! The markings of the liners were actually correct, and the 6 ounces of water lined up with the 6 ounce mark...so it is the liner bottles that are incorrect. We then got out my liquid measuring cup in the kitchen and confirmed that the measurements on the outside of the bottle are indeed wrong.
So this entire time we had been giving her 3 scoops of formula with only 4 ounces of water, a concentrated mix of liquid, which was making her terribly uncomfortable. Ever since this revelation feedings have been significantly easier...I wouldn't say like night and day, but she does not struggle to take down the formula like she had those few days on the concentrated mix. She still spits up, but we have just come to grips with the fact she is a happy spitter.
So the moral of this tale is that if you are using Playtex Drop-In Bottle System, please do yourself a favor and measure the water outside the bottle to make sure you are using the correct water to powder ratio!!