Table 3.

The preterm infants’ cues during breastfeeding

Author/year	The characteristic of the preterm infants’ cues during breastfeeding
	Category	Behavior/indicator
Lin et al. (2013)	Hunger cues	Suck searching, holding nipple, mouthing, and sucking
	Self-regulation cues	Liquid loss/drooling, closing mouth, tongue extension and spit nipple out, grimace and frown, pause sucking, break/intermittent sucking, and yawning
	Stress cues	Nausea, changing color around mouth and nose/ cyanosis, breathing rapidly and nasal flaring, hiccup, reflux, coughing or choking, fussing, disturbing, consciousness change, back arching, crying/cry-like sound
	Satiation Cues	Falling asleep, turning head, and pushing away
Giannì et al. (2017)	Sucking quality at breast*	Good connection with strong and coordinated latching at first, but developed into signs of fatigue with feeding progression, active sucking between 8 and 15 min (score = 4) Difficult in keeping latching well, active sucking for < 15 min (score = 3) Weak/inconsistent clasp needs frequent re-latch; it is considered a non-nutritive breastfeeding situation (score = 2) Various inability to latch, such as uncoordinated sucks-swallows-breath (score = 1)
Nyqvist et al. (1996)	Cues of approach	Autonomic system Steady heartbeat, functional respiration, good oxygenation, unvaried skin color, normal digestive function, occasional twitches, and startles
		Motor System Controlling strength of muscles, flexing the arm kept; keeping the body and legs pressed against the breast, holding the mother’s body, holding the hand close to the face, or clenching the hand to the mouth, licking, smiling, pressing the breast like a cat, sucking, squeezing, scratching the breast, fitting on the mother’s body, and doing coordinated smooth movements
		Behavioral State Stable moment of wake and sleep; easy to distinguish states; focused look at mother, interested look, deep sleep; smooth state transitions: calm woken, fast asleep; behave to self-calming; quick stop stimulation
		Attention and interaction system Orienting towards mothers’ face, voice, other objects, or events; raising eyebrows, frowns; pursed lips; speech movement, face expression mimicking; making howl sounds
	Cues of avoidance	Autonomic system quick, slow pulse; dynamic breathing, slow-fast or irregular; changing skin color, light color, bluish, reddish, darkish; salivation, grunting sound of the bowel, gags, bowel movement grunting, sighs, puff and pants, hiccough, shiver, tremor
		Motor System Weak hand muscle, upper and lower extremities, body, open mouth, tongue exposed; body extension: flabby
		High muscle tone Body extension: uptight; extent arms, leg movement; moving forward-backward or turned head and body; spread fingers; tightly clenched fist, distorted expression; stretches tongues; overripe flexion; maladjustment to mother trunk; a wriggling movement; jerk and free movements.
		Behavioral State Sleepy, drowsiness, short awake, circling and staring, sensitive, hard to be calmed down, anxious, tempered crying
		Attention and interaction system Distracted view, looking around in many directions, sensible, crying, drowsiness, agitated, yawn, sneezes; cues of avoidance in autonomic/motor/behavior state system
Nyqvist et al. (1999)	Infant’s behavior	Rooting, areolar grasp, latch-on, sucking, longest sucking burst, and swallowing