What I find interesting is that our first didn't eat for TWO DAYS until we got that piece of silicone. It was recommended by the lactation consultant, but the hospital didn't stock them because they had a policy against assistive devices. It took two days because the lactation consultant didn't work weekends.
The hospital's view was essentially: Breastfeeding had to "just work" or else formula. Nothing in-between. Ultimately our kid was 90% breastfed with minimum supplemental formula, we also were able to move away from the Nipple Shield within a month. But yet things like Nipple Shields get fought even by some lactation consultants and many hospitals.
You can find numerous articles pointing out why they're bad, but in my view "fed is best" and by attacking assisted devices like they do, all they're indirectly doing is hurting mothers trying to breastfeed, many of which will give up, and just use formula (since they're essentially called bad mothers either for using assisted devices OR formula, so may have well lean into it).
When we had our second, he was a larger baby, and while we did need the shield, he only needed it for a week total. The different lactation consultant recommended "trying without" every time we met her even when it was self-evident it was ineffective.
TL;DR: Breastfeeding information, advice, and assistance is shit-tier in the US and is very hit-or-miss.
