Baby bottle
A baby bottle is a bottle with a nipple to drink directly from. It is typically used if someone can not (as conveniently) drink from a cup, for feeding oneself or being fed.
In particular it is used to feed an infant infant formula, expressed breast milk or pediatric electrolyte solution.
A large-sized bottle typically holds 270 mL; the small size 150 mL. It is composed of a bottle itself, a nipple, a ring to seal the nipple to the bottle, a cap to cover the nipple and optionally a disposable liner.
The height-to-width ratio of bottles is high (relative to adult cups) because it is needed to ensure the contents flood the nipple when used at normal angles; otherwise the baby will drink air. However, if the bottle is too tall, it easily tips. There are asymmetric bottles that ensure the contents flood the nipple if the bottle is held at a certain direction.
"Vented" bottles allow air to enter the bottle while the baby is drinking without the need to break the baby's suction during feeding. Alternatively a bottle liner can be used to enclose the formula instead of directly in the bottle. The liner collapses as the formula is drained.
Vented bottles work by allowing air to enter while preventing the liquid inside from escaping. pores that allow the entry of air without the escape of liquids. This avoids the caregiver having to get the sealing ring tension just right. It remains to be seen whether these materials can withstand the rigours of daily cleaning and sterilization. Another competitor, plastic. Since bottles have to be sterilized the plastic are automatically dishwasher-safe.
The nipple itself is typically slimmer and more flexible than the mother's real nipple. Babies usually find feeding from the bottle easier than breastfeeding. Specialized nipples that mimic the shape of the breast exist to allow babies to switch back and forth between bottle feeding and breast feeding for cases where "nipple confusion" occurs. Nipples come in a selection of flow rates. Different flow rate nipples either have more holes or larger holes. The correct flow rate needs to selected based on the age of the infant. Variable flow rate nipples are available for older infants. The hole is asymmetric so that by turning the bottle/nipple, different flows can occur. Specialized nipples are available for infants with cleft palate.
While infant formula is highly regulated, baby bottles are not. Only the materials of the nipple and bottle itself are specifically regulated in some countries (e.g. British Standards BS 7368:1990 "Specification for babies' elastomeric feeding bottle teats" ). In the USA, the FDA also regulates nipples and the bottle materials. In 1985 it tightened allowable levels of Consumer Reports study suggesting that plastic bottles release unsafe amounts of bisphenol A was denounced as sensationalism because of the unreasonable conditions the bottles were subject to.
Bottles may be designed to attach directly to a breast pump for a complete "feeding system" that maximizes the reuse of the components. Such systems include a variety of drinking spouts for when the child is older. This converts the bottle into a rubber provided a material that was soft and could withstand the heat of sterilization. Elijah Pratt of New York patented the first rubber nipple in 1845 . It took until the 1900s before the technology was perfected for a pratical soft nipple such that the baby bottle could become a practical and safe alternative to breastfeeding.
