Welcome to our bonus feeding blog post!
In part 3 of our 4 part series on feeding I discussed typical oral motor milestones. I briefly reviewed what reflexes are present at birth and at which ages those reflexes are integrated. I thought it would be beneficial for our understanding of feeding development to discuss reflexes in more depth.
Did you know that swallowing is a reflex? Once a swallow is triggered you can’t stop it. Try it out! In newborn babies, sucking is a reflex too. Reflexes develop in utero, before a baby is born.
Reflexes In Utero
11-13 weeks post conceptual age: non-nutritive sucking movements are noted. This is sucking not related to nutrition – thumb sucking is an example of non-nutritive sucking.
12 weeks post conceptual age: fetal swallowing starts. Babies in utero practice swallow amniotic fluid. They can taste it too – different flavors the mother eats give flavor the amniotic fluid. Be sure to expose your baby to a wide variety of flavors. Studies have shown that babies who experience more flavors while in utero are more likely to eat prefer that flavor when starting solid foods.
28-29 weeks post conceptual age: transverse tongue reflex. Like swallowing, this is a reflex that stays with you throughout your life span. If you either touch the tongue or stimulate the tongue with taste on either side, the tongue will move toward that side. Try it! Movement of the tongue from side to side helps us manage food so that we can swallow it.
34-36 weeks post conceptual age: nutritive sucking begins. Nutritive sucking is related to nutrition. This pattern of sucking is different than non-nutritive sucking. When a baby is taking milk from a breast or a bottle is an example of nutritive sucking.
37 weeks post conceptual age: coordination of the suck – swallow – breathe pattern. That is the pattern babies use when activating the nutritive suck reflex. They suck, then swallow, then breathe. You can’t breathe while you swallow. Try it! That’s an easy way to tell if a baby is using the nutritive suck: check for the suck – swallow – breathe pattern.
Reflexes Present at Birth
38-40 weeks post conceptual age:
Phasic bite reflex – this is not a functional bite, but simply up and down movement of the jaw.
Palmomental reflex – this is when a twitch of the chin is noted when touching a specific part of the palm. Have a look at this video to see what it’s like. We lose this reflex between 2 – 6 months of age, but it can reappear with trauma to certain areas of the brain.
Rooting reflex – this is when you stroke a baby on the lips or cheek and they turn in that direction and make sucking motions. Click here to see a video of the rooting reflex.
Central Pattern Generator
The central pattern generator sounds like some kind of machine, but really, it’s circuits of neurons that generate rhythmic motor movements like walking, breathing, swimming, or sucking. Sucking is controlled by the central pattern generator at birth.
Loss of Reflexes
A baby begins to lose the rooting, palmomental, and phasic bite reflexes between 2 -6 moths of age. It is also sometime during this age range that the babies lose the central pattern generator that supports sucking rhythms.
With the exception of the palmomental reflex, each of these reflexes helps baby get the nutrition they need to grow and eventually eat solid foods. The reason for the palmomental reflex is a mystery.
Keep in mind that this is just a guideline, and every baby develops at a different pace. Babies who are born prematurely might follow a different timeline.
If you ever have concerns about your child’s feeding, speech, or language development, the therapists at Speech & Health are here to help. Please call us at 720-696-2317 or email info@speechandhealth.com to schedule your free consultation.
Resources
American Academy of Pediatrics – Non-Nutritive Sucking
What To Expect – Fetal Swallowing
Medical Dictionary – Phasic Bite
PubMed – Central Pattern Generator
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