Babies Breastfeeding As Baby Grows Nutritive and Non-Nutritive Sucking and Breastfeeding By Melissa Kotlen Melissa Kotlen Melissa Kotlen is an International Board-Certified Lactation Consultant and Registered Lactation Consultant. Learn about our editorial process Updated on November 21, 2022 Medically reviewed by Rebecca Agi, MS, IBCLC Medically reviewed by Rebecca Agi, MS, IBCLC Rebecca Agi, MS, IBCLC is a board-certified lactation consultant and founder of Best Milk LA, a lactation consulting service. She is a nationally recognized lactation expert, who's been featured in several media outlets. Learn about our Medical Review Board Print MNPhotoStudios / Getty Images Table of Contents View All Table of Contents The Sucking Reflex Sucking and Breastfeeding Comfort Nursing Flow Rate Newborn babies spend much of their waking hours nursing or bottle-feeding. In the exhaustion of new parenthood, it's easy to dismiss how remarkable it is that babies come into the world already knowing how to eat. In fact, rooting (looking for the breast) and sucking are natural reflexes that get newborns off to a good start on mastering the art of breastfeeding or bottle-feeding. The primary purpose of sucking is feeding. When babies are sucking and swallowing breast milk or formula, they are gaining needed calories for growth and development. Sometimes, though, infants suck for non-nutritive purposes, using the breast or a pacifier simply for comfort. Learn more about why and when babies might use nutritive or non-nutritive sucking. The Sucking Reflex Rooting and sucking are primal reflexes. Fetuses practice sucking in the womb by swallowing amniotic. You can stimulate the instinctive process of feeding by touching the roof of a baby's mouth. For both breastfeeding and bottle-feeding, this happens when the nipple of the breast or bottle enters the baby's mouth. Pressure from the nipple on the roof of the mouth prompts the baby's sucking action. Sucking, along with simultaneous movements of the tongue, draws out the milk. Swallowing begins when a force of fluid reaches the back of the throat. As the baby swallows, the part of the throat connected to the nasal passages closes off. This process briefly suppresses the baby's breathing, an action that helps the baby drink without choking on the milk. What Is the Sucking Reflex? Sucking and Breastfeeding When a baby latches on to the breast and begins to suck, this prompts a milk ejection (let-down reflex) from the milk ducts in the breasts. This action makes a sufficient amount of breast milk available in the area just under the areola. As the baby sucks and moves their tongue from the areola to the nipple, the breastmilk drains out through the nipple. Each suck is followed by a swallow. This pattern repeats quickly and continuously as long as milk is immediately available and the baby is hungry—about one suck per second. We call this "nutritive sucking." There is high milk flow during this period of frequent swallowing. You'll see the baby's jaw moving as they swallow the milk. They may start out sucking quickly and then move toward a slower sucking-swallowing pattern as they get to the hindmilk (the higher fat content milk that comes at the end of a feeding). With bottle-feeding, the baby does a similar sucking action with the nipple of the bottle. Overview of Breastfeeding and Foremilk Comfort Nursing Non-nutritive sucking, also called comfort nursing, is when a baby is going through the motions of nursing but not drinking milk. Alternatively, babies may use a pacifier or their fingers for this type of sucking. Generally, babies seek non-nutritive sucking for relaxation and comfort. It often helps them fall asleep. When they are distressed or uncomfortable, non-nutritive sucking often provides relief. Non-nutritive sucking may occur in a few different instances: At the end of a feedingBetween nutritive sucksWhen the baby is at the breast and the lactiferous sinuses (the spaces inside the breast near the nipple that hold milk) aren't full With non-nutritive sucking, the pattern does not repeat quickly and continuously, but rather slowly and with longer periods of rest. Small amounts of milk may be entering the baby's mouth. During this period, the baby needs many sucks to collect an adequate amount of milk to activate a swallow. What Is Comfort Nursing? Flow Rate Another important variable is flow rate, or how quickly milk comes out. This affects how fast the baby will suck and swallow. The quicker the milk flows, the faster the baby will suck and swallow. In bottle feeding, flow rates are generally very consistent; in breastfeeding, they are extremely inconsistent. Before and between milk ejections, and at the end of feedings, the flow rate is very low, which is when non-nutritive sucking occurs. However, during the first and subsequent milk ejections, the flow rates are very high—this is when nutritive sucking happens. So, babies who are breastfeeding will typically experience both nutritive and non-nutritive sucking, sometimes in the same nursing session. Breastfeeding Questions and Answers A Word From Verywell Nutritive sucking nourishes, while non-nutritive sucking provides comfort. If you are breastfeeding, you can choose whether or not and how much to allow your baby to comfort nurse. A pacifier or their fingers can also offer similar relaxation. However, don't let your baby suck on an empty bottle, as this can introduce excess air into the baby's tummy. If you have any questions about your baby's sucking, their fussy periods, their sleep, or their feeding, consult a healthcare provider. Common Breastfeeding Questions and Challenges 9 Sources Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. American Academy of Pediatrics. Baby's first month: feeding and nutrition. U.S. National Library of Medicine. Amniotic fluid. American Academy of Pediatrics. Newborn reflexes. World Health Organization. Infant and young child feeding: model chapter for textbooks for medical students and allied health professionals: The physiological basis of breastfeeding. La Leche League International. Positioning. Lau C. Development of suck and swallow mechanisms in infants. Ann Nutr Metab. 2015;66 Suppl 5:7-14. doi:10.1159/000381361 Feştilă D, Ghergie M, Muntean A, Matiz D, Şerb Nescu A. Suckling and non-nutritive sucking habit: what should we know?. Clujul Med. 2014;87(1):11-14. doi:10.15386/cjm.2014.8872.871.df1mg2 Geddes DT, Chooi K, Nancarrow K, Hepworth AR, Gardner H, Simmer K. Characterisation of sucking dynamics of breastfeeding preterm infants: a cross sectional study. BMC Pregnancy Childbirth. 2017;17(1):386. doi:10.1186/s12884-017-1574-3 American Academy of Pediatrics. Bottle feeding basics. Additional Reading Riordan J, Auerbach KG. Breastfeeding and Human Lactation. Jones and Bartlett. By Melissa Kotlen Melissa Kotlen is an International Board-Certified Lactation Consultant and Registered Lactation Consultant. See Our Editorial Process Meet Our Review Board Share Feedback Was this page helpful? Thanks for your feedback! What is your feedback? Other Helpful Report an Error Submit Featured Video