Problem Area / intra oral vacuum strength of the infant with significance for breastfeeding The period from birth to the premature infant feed exclusively at the breast without supplementary tube feeding varies from weeks to months, depending on how early the infant is born. The premature infant is characterized as being immature and with low muscle tone and therefore, a decreased ability to breastfeed the first time. The transfer of milk from mother to infant is an interaction between the mother and her milk ejection reflex creates a positive pressure on the milk and the infant creates a vacuum. If the infant not create a vacuum at the back of the mouth, the nipple of the mother is just pushed together and the infant is not transferred milk from the breast to the oral cavity. The amount of milk is regulated in relation to demand and a weak or shortage of vacuum will cause a shortage of milk transfer, which in turn physiologically will lead to less milk production and thereby decreasing amount. Studies that investigates this process and measured intra oral vacuum, shows all the importance of the infant's contribution by milk transfer, but does not answer to the extent the premature infants ability to create vacuum importance of breastfeeding establishment and maintaining. The question is whether the premature infants sucking strength is too weak to establish sufficient intraoral vacuum to ensure milk transfer from the breast to the infant and it can be related to a fewer number of days where the infant is exclusively breastfed.