Infant Terminology and Reflexes
Introduction[edit | edit source]
Every year there are an estimated 15 million babies born too early. Babies born before 37 weeks are considered preterm. Depending on the gestational age, preterm can be further divided into three sub-categories:
- 32-37 weeks: moderate to late preterm
- 28-32 weeks: very preterm
- less than 28 weeks: extremely preterm
Complications from preterm birth include death, disability, learning disabilities and visual and hearing problems. Half of the babies born at or below 32 weeks die while almost all babies survive in high-income countries. Preterm babies that survive in middle-income countries have an increased burden of disability.
Often times preterm births occur spontaneously. Some of the known causes for preterm birth include:
- infections
- multiple pregnancies
- diabetes
- high blood pressure
- genetics
** Often times there is no reason for preterm birth.[1]
affects reaching milestones when they were born
Birth weight
irth weight is 2,500 to 4,000 grams or five pounds, eight ounces to eight pounds, 13 ounces. Low birth weight is anywhere from 1501 to 2,500 grams. Very low birth weight is 1000 grams to 1500 grams and extremely low birth weight is an infant that weighs less than 1000 grams at time of birth. Now there are a number of
factors affecting birth weight: Such as ethnicity, the maternal age, maternal health, amount of maternal weight gain in pregnancy, birth order, gestational age, and genetics.
Apgar score[edit | edit source]
The apgar score is a quick test performed after birth to report the status of the newborn infant. The test consists of five components:
- heart rate
- respiratory effort
- muscle tone
- reflex irritability
- color
Each factor is given a value from 0-2 with total scores being between 0-10. The apgar score is convenient, accepted and quick and reported at 1 and 5 minutes after birth. [2]
Various ages
- gestationsal
- chronological
- adjusted or corrected age- when they were born vs. when they were supposed to be- use this for milestone for the first two years of life
Primitive Reflexes[edit | edit source]
Primitive reflexes are involuntary survival-oriented motor responses. These reflexes develop in utero and strengthen postnatally. As the nervous system develops, these reflexes become integrated and diminish during the first three years of life. As neonates are not capable of cortically directed movements, primitive reflexes functionally provide the infants to interact within their environment. The absence or persistence of a reflex could indicate a neurological issue.[3][4][5]Delays in primitive reflex integration correlates to reduced sensory processing and delayed milestones. Motor skills, coordination and balance may be affected with persistent reflex activity preventing the child from moving fluidly. Learning difficulties and behavioural problems are also linked to persistent reflex activity.[6] [7]
See below for a list of primitive reflexes:
| Reflex | Description | Initiated | Integrated |
|---|---|---|---|
| Palmer Grasp | stroke palm of hand, grip finger | birth-2 months | 4-11 months |
| Plantar Grasp | stroke sole of foot, toes curl | birth | 9-12 months |
| Rooting | stimulus provided at cheek or lip and infants turns toward it | prenatal | 3 months |
| Sucking | root of mouth touched, baby will suck | prenatal | |
| Galant | strokes along paravetebral line activates trunk flexion toward stimulus | prenatal | 3 months |
| Moro | when startled, arms, legs and neck into extension followed by arms together rapidly | birth | 2 months |
| Babinski | stroke on foot from heel to toes, big toe moves upward-remaining toes fan out | 3-4 months | 12-24 months |
| Parachute | arms move forward if they perceive falling | 5-9 months | persists |
| Stepping | holding baby under arm and feet touch surface, will simulate walking | birth | 2 months |
| Flexor Withdrawl | noxious stimuli to the foot; foot withdraws using hip and knee flexion | prenatal | 1-2 months |
| Crossed Extension | noxious stimuli applied to an extended leg; flexion on stimulus leg and weight shift and extension on contralateral side | prenatal | 1-2 months |
| Proprioceptive Placing | brush the dorsum of the feet against the edge of a surface; will flex up hip and knee and lift foot up to surface then extend leg to accept weight through their leg | prenatal | 2 months |
| Positive support | feet on contact surface in a weight-bearing suspension; infant accept weight through bilateral legs; extension of trunk, hip, knees | prenatal | 1-2 months |
| Landau | prone in air supported; head, hips and back should extend | 3-4 months | 12-24 months |
Tonic reflexes[edit | edit source]
Tonic reflexes elicit a holding response or cessation of movement. Once placed in a particular position the infant's muscles will stay contracted and hold that position.[4]
| Tonic Reflexes | Description | Initiated | Integrated | Purpose |
|---|---|---|---|---|
| Asymmetrical tonic neck reflex (ATNR) | with lateral rotation of the head, extension of the upper and lower extremity on face side, flexion on skull side | birth-2 months | 4-6 months | motion in utero; promote early visual regard for hand; hand-eye coordination; break up symmetrical patterns |
| Tonic labyrinth | in prone, all limbs and head flex- in extension, all limbs and head extend | birth | 6 months | |
| Symmetric tonic labyrinth (STNR) | flexion of the neck causes flexion of the upper extremities and extension of lower extremities; neck extension elicits the opposite | 4-6 months | 8-12 months | assist with disappearance of flexion posture in prone to allow for quadruped; help with creeping |
Righting Reactions[edit | edit source]
Righting reactions are automatic responses to maintain a normal upright posture.[4]
| Righting Reaction | Description |
|---|---|
| Optic Righting | using vision to maintain head in a vertical position |
| Labyrinth | using inner ear to maintain head in a vertical position when vision is obstructed |
| Neck Righting | when body is titled one way, neck maintains head in vertical position |
| Vertical Righting | when body is titled one way, neck and trunk on opposite side of shift will shorten to maintain vertical position |
| Rotational Righting | body on body: flexing either an upper or lower extremity and crossing it over midline to initiate rolling
head on body: as head rotates the body will follow for rolling |
Resources[edit | edit source]
References[edit | edit source]
- ↑ World Health Organization: Preterm Birth. 2022.[1] Available from: https://www.who.int/news-room/fact-sheets/detail/preterm-birth
- ↑ Cnattingius S, Johansson S, Razaz N. Apgar score and risk of neonatal death among preterm infants. New England Journal of Medicine. 2020 Jul 2;383(1):49-57.
- ↑ Modrell AK, Tadi P. Primitive Reflexes. InStatPearls [Internet] 2021 Mar 21. StatPearls Publishing.
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 Eskay, K. Infant Terminology and Reflexes. Plus. 2023
- ↑ Melillo R, Leisman G, Mualem R, Ornai A, Carmeli E. Persistent Childhood Primitive Reflex Reduction Effects on Cognitive, Sensorimotor, and Academic Performance in ADHD. Frontiers in public health. 2020:684.
- ↑ Pecuch A, Gieysztor E, Wolańska E, Telenga M, Paprocka-Borowicz M. Primitive reflex activity in relation to motor skills in healthy preschool children. Brain Sciences. 2021 Jul 23;11(8):967.
- ↑ 7.0 7.1 7.2 Hickey J, Feldhacker DR. Primitive reflex retention and attention among preschool children. Journal of Occupational Therapy, Schools, & Early Intervention. 2021 Apr 4:1-3.
- ↑ 8.0 8.1 Thelen E, Fisher DM, Ridley-Johnson R. The relationship between physical growth and a newborn reflex. Infant behavior and development. 1984 Oct 1;7(4):479-93.
