Infant Terminology and Reflexes

Intro

early term 37-38 weeks

late term 41 weeks

post term 42 weeks

affects reaching milestones when they were born

28 weeks-life is viable; very extremely

preterm

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:

1. The Apgar score consists of five components (heart rate, respiratory effort, muscle tone, reflex irritability, and color), each given a value from 0 to 2. Thus, total scores range from 0 to 10, with higher scores indicating a better physical condition. e. The Apgar score provides an accepted and convenient method for reporting the status of the newborn infant immediatelypgar is a quick test performed on a baby at 1 and 5 minutes after birth. after birth
3. grimace
4. appearance
5. respiration

Various ages

1. gestationsal
2. chronological
3. 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

Primitive reflexes are involuntary motor responses originating in the brainstem present after birth in early child development that facilitate survival.

rimitive reflexes are adaptive reactions in the neonate and diminish as the brain and nervous system mature. Most of these reflexes can be present in normal individuals, even in young adults.

The delay of integrating these reflexes at a typical developmental correlates with delays or deficiencies in reaching milestones and a reduced ability to process sensory information [1,12,15].Persistent reflex activity can influence the quality of a child’s motor skills, especially coordination and balance. They may be linked to learning difficulties and behavioral problems [9,10]. Incomplete integration of primitive reflexes may cause an involuntary motor response in a reflex pattern. The reflex tensions and uncontrolled movements require conscious and increased control over the child’s motor activities. Their activeness prevents the child from moving fluidly. Non-integrated primary reflexes are described in the literature among the factors that contribute to disorders in the harmonious motor development of the child—they are manifested by clumsiness and frequent learning difficulties

Primitive reflexes are stereotypic, automatic, survival-oriented movements (Taylor, Houghton, & Chapman, 2004). The emergence of these brainstem-mediated primitive reflexes often begins in utero, and they then strengthen postnatally; gradually, these integrate during the first three years of life.Functionally, these reflexes allow neonates and infants to interact with their environments through reflexive movements before they are capable of cortically directed actions. However, with ongoing development it is important that children gain volitional control over these reflexive responses, engaging voluntarily in cortically directed, meaningful occupations such as play, self-care, education, and social participation. Failure to integrate these reflexes in the typical developmental stage has been shown to correlate with developmental delays, including interruptions to milestone achievement and decreased ability to process sensory information

Reflex	Function	Initiated	Integrated
Palmer	stroke palm of hand, grip finger	birth-2 months	4-11 months
Plantar	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 started, will bring arms and legs and neck into extension followed by rapidly bringing arms together	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 and the foot withdraws using hip and knee flexion	prenatal	1-2 months
Crossed Extension	noxious stimuli applied to an extended leg- flexion on that 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

develop in utero

as nervous system develops, they begin to disappear/integrated

absensce of it or persistance of one could indicate a neurological issue

Tonic reflexes

Tonic Reflexes
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
Tonic labyrinth
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 quadraped

Righting reactions

Neck righting
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

Modrell AK, Tadi P. Primitive Reflexes. InStatPearls [Internet] 2021 Mar 21. StatPearls Publishing.