NaturalWave™ nipple was specially designed to allow the baby to mimic the same tongue movements used during breastfeeding. This makes it easier to transition between breastfeeding and bottle feeding. Like all our products, Lansinoh NaturalWave nipple was created to enable mothers to breastfeed longer with the option of pumping and feeding the baby breast milk with reduced risk of nipple confusion.Clinically proven, Lansinoh NaturalWave nipple supports the baby's natural way of sucking. Extensive research has shown that infant sucking is very different from adult sucking and involves three key steps.These include initial latch, peristaltic tongue movement (your baby's tongue moves in a wavelike motion), and swallowing.It is crucial for the baby to be able to perform peristaltic tongue movement as it supports natural oral development and jaw development.RECOMMENDATION: We recommend exclusively breastfeeding for 6-8 weeks before introducing the bottle to allow the baby to develop proper sucking habits.