Developmental Concerns for Preemies
When babies are born premature (born before 37 weeks,) they spend those last weeks or months of gestation developing outside of the uterine environment where they are subjected to gravity, tons of sensory stimulation, and necessary medical procedures. One concept I talk about all the time when working with a family in the NICU, is how these early experiences shape our long term development. The brain and muscle are wiring together, sensory systems continue to develop, and babies are learning how to interact with the world.
Frist, let’s talk about adjusted age and how we assess development for premature babies. For any baby born before 37 weeks, we correct their age as if they were born on thier due date. This gives them credit for the time they missed developing in the womb.
For example, a baby who is 4 months and 7 days old but was born at 33 weeks and 5 days gestational age is 2 months and 25 days adjusted.
So we look for developmental milestones (motor, communication, feeding, etc.) based on that adjusted age. We stop adjusting the age at 2 years old, and our goal is that at 2 years old their developmental skills are on track for their calendar age. Some babies catch up before the 2 year mark, and some continue to need therapy support after 2 years if they are not yet on track. So next time you catch yourself comparing your preemie to another baby, or are worrying they haven't started rolling, make sure you think about their adjusted age! One of my favorite online adjusted age calculators is here.
Common Developmental Concerns we see in Preemies
Extension Bias
The muscles that run along the front of out body are flexors, and the muscles along the back of our body are extensors.
Preemie babies can start to overuse the extensor muscles, leading to weakness in the flexor muscles.
There are many reasons why we see some preemies develop this bias:
Did not have a chance to develop “physiologic flexion”
Babies are their largest in the last couple weeks of gestation, and since there is less room in utero they get resistance training pushing into mom’s abdominal wall which develop strength in the flexor muscles
When born preemies are more susceptible to gravity which wants to pull their body into extension
If baby has difficulty breathing, reflux, or other medical issues they often arch or try to make space in their chest and abdomen leading to extension
The brain and muscles are wiring together in the first weeks of life, and if baby is spending more time in extension the brain starts to prefer this position
As baby gets older and starts to work on new movements and motor skills, they now have more strength in the extensor muscles and the brain prefers this position. However, almost all of our early motor skills require baby to move into flexion so if baby moves more into extension they might struggle to achieve motor skills.
What to look for at home:
Frequent arching (especially when calm)
When laying on their back baby keeps hands away from the middle of their body
During diaper changes their legs feel really stiff
How to support your baby:
When holding your baby support them in a flexed position (hands together at the middle of the chest, knees and hips flexed, back slightly rounded)
When playing on their back encourage hands coming together at the middle of the body and hands to feet
Side-lying play with hands together at the midline
Tummy time!
Torticollis and Head Shape
Babies who spend time in the NICU are at increased risk for torticollis and abnormal shape of the skull (most commonly Plagiocephaly or Scaphocephaly.) This can be related to:
Increased time sleeping and being in one position
Baby might need to be in one position repeatedly to help them breathe or for other medical concerns
Decreased strength to turn head on their own
NICU set up, many times all of the “exciting” parts of baby’s world is on one side of their isolette or crib (think beeping monitors, parent chairs, when nurses approach, etc) which teaches their brain early on that one side is better then the other
Increased stress in the NICU environment and baby positions head in the same way they were positioned in utero to seek comfort
Any related positioning can contribute to these conditions, we have a whole blog post dedicated to Torticollis and head shape coming soon if you want to learn about these conditions!
What to look for at home:
Baby prefers to turn and/or tilt their head one direction (look at pictures if you are not sure)
Baby cannot turn their head once direction or their neck feels stiff
Breastfed baby has difficulty feeding on one breast
Baby has flattening on one part of their skull or the skull looks long and narrow (best way to assess is a Birds Eye view, after bath if they have hair!)
How to support you baby:
Approach your baby from different sides
Encourage play looking to different sides
Flip their head to the opposite end of their sleep space every other night
Sensory Processing and Overstimulation
Infants who were premature are sometimes easily overstimulated because their sensory systems were not fully developed when they were born.
Tactile system (touch) develops first
Vestibular system (balance and equilibrium) develops next
Gustatory system (taste) develops by around 24 weeks gestational age
Olfactory system (smell) also develops by around 24 weeks gestational age
Auditory system (hearing) develops between 25 and 29 weeks gestational age
Visual system (sight) if the last system to develop when an infant is close to full term. Interestingly, the visual system develops when baby is sleeping!
What to look for at home: You are the expert on your baby, and you have most likely learned how they communicate with you. Babies will demonstrate stress cues such as turning red, averting gaze, grimacing, pursed lips, outstretched hand with fingers open, fussing, etc when they experience too much sensory stimulation.
How to support your baby:
It is beneficial to explore new sensory experiences, while providing breaks when they show you their stress cues.
For babies who are at least 40 weeks by their adjusted age: Exploration can include eye contact of a stationary object, eye tracking of a moving object, gently rubbing a soft toy on their arm or hand, infant massage, bath time, quiet singing or talking, etc.
Some babies can only tolerate one type of sensory input at a time so take care to watch for stress cues and slowly introduce new sensory experiences.
If they demonstrate stress cues they might need support from you to calm such as cradle hold, decreased stimulation or moving to a quiet environment, sucking on a pacifier, etc.
When to seek support from a Pediatric Physical Therapist
Your baby has a preference to turn their head to one side or move one side of their body more
You notice a flat spot on their head or feel their head shape is not normal
Your baby is not hitting milestones as expected
Your baby frequently arches their back
Your baby seems to have a hard time moving their arms or legs
Your baby’s muscles are very loose or very stiff
PT was recommended by another professional who follows your baby
Many baby’s who were in the NICU qualify for developmental follow up programs like a developmental clinic or home visiting nurse. If your preemie does not receive any developmental follow up and you would like support, we also offer Development Support Sessions to screen for common concerns and help you understand how to support your unique baby!
References:
Babik I, Galloway JC, Lobo MA. Infants Born Preterm Demonstrate Impaired Exploration of Their Bodies and Surfaces Throughout the First 2 Years of Life. Phys Ther. 2017 Sep 1;97(9):915-925. doi: 10.1093/ptj/pzx064. PMID: 28605484.
Dusing SC, Kyvelidou A, Mercer VS, Stergiou N. Infants born preterm exhibit different patterns of center-of-pressure movement than infants born at full term. Phys Ther. 2009 Dec;89(12):1354-62. doi: 10.2522/ptj.20080361. Epub 2009 Oct 8. PMID: 19815647; PMCID: PMC2794478.
Dusing SC, Harbourne RT. Variability in postural control during infancy: implications for development, assessment, and intervention. Phys Ther. 2010 Dec;90(12):1838-49. doi: 10.2522/ptj.2010033. Epub 2010 Oct 21. PMID: 20966208; PMCID: PMC2996511.