In addition to the premature infants muscle tone has its immaturity also affect the organization and quality of body movements. Organization and quality in the movements may be referred to neuro motor processes and form among others the oral motor base supporting the movements involving the infant's ability to create vacuum. The processes preceding the creation of vacuum and studies have shown that by early intervention with oral stimulation in the form of stimulation of the nerves and muscles in and around the mouth, it can be oral motor basis strengthened. Studies where the infant carefully is stimulated with a finger, showing that the premature infant's muscles and sucking reflex can be influenced so that it is able to suck a larger volume in a shorter time in the bottle compared to the infant that is not stimulated orally. This presents an opportunity to influence the premature infant´s strength and maybe increase the ability to create intra oral vacuum affected by oral stimulation as a skill the infant preserves. The question is whether oral stimulation can increase the premature infant's ability to create vacuum and thus increase the power to transfer milk from the breast and thereby extending the number of days when with exclusively breastfed? The 3 studies are based on the same cohort. The cohort is identified and recruited at the Neonatal Intensive Care Unit at Hvidovre Hospital and relevant families where the mother delivers prematurely are included consecutively in accordance to the inclusion and exclusion criteria. The cohort will be demographically representative of everyday life in clinical practice with various family formation, education levels and socio-economic background conditions.