Understanding the Sucking Reflex in Newborns

This involuntary movement is crucial for eating and self-soothing

Mother with baby
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The sucking reflex is probably one of the most important reflexes your newborn has, especially when you pair it with the rooting reflex. Find out why. 

Test Out the Sucking Reflex

If you touch the roof of your baby’s mouth with your finger, a pacifier or a nipple, he will instinctively begin sucking. Around two to three months of age, your baby’s sucking will be a result of conscious effort and no longer a reflex.

Be aware that every time your baby exhibits this reflex, it doesn’t necessarily mean that he’s hungry. Sucking is a soothing, enjoyable activity for your baby all by itself. Babies also have a hand-to-mouth reflex that goes with rooting and sucking and may suck on fingers or hands. 

The Sucking Reflex and Breastfeeding

One reason some mothers may get a slow start breastfeeding has to do with this reflex. It’s not just the nipple that needs to go into your baby’s mouth, but a fair amount of your areola as well. If you just have the tip of your nipple in his mouth, it may not be far enough back to stimulate this sucking reflex. In addition, the milk sinuses won’t be properly compressed by your baby’s tongue and jaw.

Premature Babies and Sucking Problems

The sucking reflex is not fully developed until about 36 weeks of pregnancy, which means that premature babies may have a weak or immature sucking ability.

If your baby is premature, you may notice a combination of sucking issues, including: 

  • Disorganized or inefficient sucking patterns
  • Weakened lip seal
  • Impaired tongue shaping or movement
  • Weakened stability of the inner cheek
  • Trouble synchronizing the suck and swallow with breathing

Another complication that can impact preemies is Infant Respiratory Distress Syndrome (RDS).

Babies with RDS have difficulty synchronizing their sucking, swallowing and breathing — and this can have a negative impact on feeding as they can't withstand long feeds and tire easily. As a result, the newborn could be at risk of poor nutrition.

Other Newborn Reflexes to Try

The sucking reflex is just one of many involuntary movements newborns make as part of healthy development. If your baby is not exhibiting these reflexes, make an appointment with your health care provider.

  • Moro reflex (or startle reflex): Create a loud noise and your newborn will react by arching and extending his arms, legs, and fingers.
  • Rooting reflexStroke his cheek and your newborn will open his mouth, turning his head toward the side that was stroked in search of the breast or bottle to begin feeding. 
  • Tonic neck reflex (or fencing reflex): Place your infant on his back and his head will automatically turn with the arm and leg of one side extended (the pair on the side he’s turned toward) and his other arm and leg will be flexed. 
  • Palmar grasp: Stroke his palm with your finger and your little one will hold on tight, curling his fingers around yours.

  • Plantar grasp (or Babinski reflex): Stoke the sole of his foot and your little one will spread open his toes and turn his foot inward after you stroke the sole of his foot.

  • Stepping reflexPlace his feet on a flat surface and your newborn will look like he's "walking."