|
28 weeks |
32 weeks |
36 weeks |
40 weeks |
Ear cartilage |
Pinna soft,
remains folded |
Pinna slightly
harder, but remains folded |
Pinna harder,
springs back |
Pinna firm,
stands erect from head |
Breast tissue |
None |
None |
1-2mm nodule |
6-7mm nodule |
External genitalia – male |
Testes undescended, smooth
scrotum |
Testes in inguinal canal, few rugae |
Testes high in scrodum, more rugae |
Testes descended, pendulous scrotum covered with rugae |
External genitalia – female |
Prominent clitoris, small, widely separated labia |
Prominent clitoris, larger separated labia |
Clitoris less prominent, labia majora
cover labia minora |
Clitoris covered by labia majora |
Plantar surface |
Smooth |
1-2 anterior creases |
2-3 anterior creases |
Creases over sole |
28 weeks |
32 weeks |
36 weeks |
40 weeks |
<28 wks – persistent
stimulation leads to eye opening and alerting for seconds
>28 weeks – gentle stimulus can arouse baby and for
several minutes |
Spontaneous arousal Eyes remain open with roving movements Sleep-wake alternation |
Increased alertness
Vigorous crying when awake |
Distinct periods of attention to
visual and auditory stimuli
|
|
28 weeks |
32 weeks |
36 weeks |
40 weeks |
Passive Tone |
Minimal resistance to manipulation in all limbs |
Flexor tone in lower extremities |
Prominent flexor tone in LE palpable in UE |
Strong flexor tone in all extremities |
Pull to sit |
|
Complete head lag |
|
Head held in same plane as body for several seconds |
|
28 weeks |
32 weeks |
36 weeks |
40 weeks |
Extinguished |
Moro |
Hand opening |
Extension and abduction, Audible cry |
Mature response by 37 weeks: extension and anterior
flexion of upper extremities followed by audible cry |
6 months |
|
Palmar grasp |
Present |
Strong |
Mature response by 37 weeks: infant can be lifted from bed |
Voluntary grasp 2 mo |
|
Tonic neck response |
Absent |
Absent |
Mature response by 35 weeks: “fencing posture,” strongest
at 1 mo postnatal |
6-7 months |
|
28 weeks |
32 weeks |
36 weeks |
40 weeks |
I olfaction |
Absent |
Mature response: arousal, sucking |
||
II vision |
Blink to light (26 wks) |
Eye closure to light Visual fixation |
Tracks (34 wks) Turns to soft light (37 wks) |
Consistent fix and follow VA 20/150 |
II, III Pupils |
|
Consistent reaction to light (32-35 wks) Increases in amplitude with gestational age |
||
III, IV, VI oculomotor, trochlear, abducens |
Oculocephalic present
(25 wks) |
Spontaneous roving Calorics
(>30wk) |
Fix and follow Initially jerky Smooth and accurate by 3mo |
|
VIII audition |
Startle/blink to loud noise |
|
|
Baby alerts, eyes widen, turns to sound |
V, VII, IX, X, XII suck and swallow |
Suck and swallow Not synchronized with breathing |
Better synchrony of breathing with suck and swallow |
Mature response at 37 weeks: fully synchronized and coordinated suck and swallow, best
after 48 hours Gag reflex |
Source: Courtesy of
Dr. Hannah C. Glass