How Newborns Communicate: Understanding Early Hunger, Stress, and Engagement Cues

By Birth & Baby University · Last updated: October 2026 · 8 min read

A newborn cannot tell anyone what they need, but they are not silent. They communicate through movement, mouth and hand behavior, changes in alertness, and eventually crying. Postpartum doulas spend hours watching babies and parents, and one of the most useful things they can offer is a calm way of reading those signals. This article covers three groups of cues that doulas are often asked about: hunger and fullness, stress, and engagement. It also explains what research supports, and where the evidence is thin.

Key takeaways

Quick answer: feeding cues are the best documented in public health guidance, with early signs such as hands to the mouth, turning toward the breast or bottle and lip movements, and crying described as a late sign. Descriptions of stress and engagement cues come mostly from developmental frameworks such as the Newborn Behavioral Observations (NBO) system, whose evidence is encouraging but limited. All cues need to be read in context, and any worry about feeding, breathing or responsiveness is a reason to contact the baby’s provider.

• The CDC lists, for birth to 5 months, hunger signs of putting hands to the mouth, turning the head toward the breast or bottle, puckering, smacking or licking lips, and clenched hands, and fullness signs of closing the mouth, turning the head away and relaxed hands. It says crying is often a late sign of hunger.
• AAP Bright Futures guidance lists hand to mouth, sucking, rooting, pre-cry facial grimaces and fussing as early hunger signs, and says parents can avoid crying by responding to the more subtle cues.
• The NBO system uses 18 observations from birth to the third month to help parents understand a baby’s communication. A 2018 Cochrane review found only very low-quality evidence for its effect on parent-infant interaction, and a large Danish trial of universal NBO found no effect beyond greater parental knowledge.
• Cues are not a guarantee. They vary between babies and shift with age, feeding method and sleepiness.

What the research says

Hunger and fullness. The CDC’s page on signs your child is hungry or full (page dated March 2026) lists these signs for birth to 5 months. Hunger: puts hands to mouth, turns head toward the breast or bottle, puckers, smacks or licks lips, has clenched hands. Fullness: closes mouth, turns head away from the breast or bottle, relaxes hands. It adds that crying is often a late sign of hunger and encourages watching for earlier indicators. AAP’s Bright Futures: Nutrition (third edition) gives a similar list for infants up to about three months, adding sucking, rooting, pre-cry facial grimaces and fussing, says crying is a late sign of hunger that often interferes with good breastfeeding, and notes that a crying infant usually needs calming before breastfeeding can begin. It is an older edition of the guide, so check for current clinical guidance as well.

A review by Hetherington and McNally (2019) describes how infants communicate appetite through a variety of behaviors: in newborns, mouthing and orientation toward odors from breast milk signal preference, infants indicate readiness to eat by sucking their hands and eliciting the hunger cry, and satiation is signaled through subtle facial expressions, shifts in gaze, changes in gesture and bodily movement, including turning the head away. Studies that filmed mealtime interactions showed how dynamic the communication is, and suggested that caregiver responsiveness may be influenced by individual characteristics and by mode of feeding. The authors argue that nutrition education has a role in helping caregivers read and respond to these cues. That is a narrative review of a research program, not a trial of an intervention.

Stress and engagement. The Brazelton Institute’s description of the NBO system organizes what newborns are working on in the first months with the acronym AMOR: autonomic or physiological stability (steadying breathing and temperature, reducing tremors and startles), motor regulation, organization of state (coping with stress and developing predictable sleep-wake patterns), and responsiveness (growing awareness of the environment and the capacity to process visual and social information and engage socially). NBO consists of 18 neurobehavioral observations designed for use from birth through the third month, and doulas are among the professionals named as users. In this framing, signs of strain can appear as difficulty steadying breathing or movement, difficulty settling, or trouble moving between sleep and wakefulness, while signs of engagement include alert attention to faces and voices and social responsiveness. This is a developmental framework, not a diagnostic checklist.

The evidence for teaching parents to read these cues is mixed. A Cochrane review of the Neonatal Behavioral Assessment Scale and NBO (Barlow and colleagues, 2018) included 16 randomized trials with 851 participants, all in the United States and all judged at high risk of bias. Overall, it found only very low-quality evidence for improving parent-infant interaction, with a significant medium-sized effect in a pooled analysis of seven studies and no evidence of an impact on maternal depression, and no adverse effects identified. A cluster randomized trial in Denmark (Kristensen and colleagues, 2020; 1,332 families in the NBO group and 1,234 in usual care) found no effect of universal NBO delivered by health visitors on maternal confidence, mood, infant socio-emotional behavior or the parent-infant relationship, other than higher maternal knowledge about the infant’s communication and how to soothe. A small trial in Iceland among mothers with distress or a history of anxiety or depression (54 women; 2025) found higher maternal confidence and knowledge with NBO, and the authors noted the small sample limits conclusions. Taken together, cue-reading education reliably increases what parents know, and whether it improves relationships or mood remains uncertain.

What this means for doulas

• Teach early cues, not just crying. Help parents notice hands to mouth, rooting, mouth movements and pre-cry grimaces, so feeding can start while the baby is calm.
• Describe cues as tendencies. Babies differ. Sucking on fingers can be comfort as well as hunger. Context, the time since the last feed and the baby’s overall pattern matter.
• Use “watch and wonder” language. “I notice she is turning away and her hands are relaxed. What do you think she is telling us?” invites the parent’s own observation, consistent with the parent-led premise of NBO.
• Link engagement to timing. A baby who is alert and looking at a face is ready to interact. A baby who is looking away, tense or unsettled may need less stimulation, a break or a feed. This is a reasonable practical reading of the AMOR framework, not a research finding about particular behaviors.
• Stay in scope. Do not interpret cues as signs of illness or a feeding disorder. Do not diagnose or recommend medical action.

Putting the evidence into practice

1. Show the CDC cue lists to parents and talk about which ones they have already noticed in their own baby.
2. Practice early responses. Offer a feed or a cuddle at the first signs, and if the baby is already crying, calm them first, as Bright Futures describes.
3. Notice fullness as well as hunger. Closing the mouth, turning the head away and relaxed hands are signs to pause or stop, according to the CDC.
4. Know when to refer. Encourage a call to the pediatric provider or lactation professional if the baby is hard to wake for feeds, is not showing hunger cues, has trouble latching or taking milk, or the parent is worried about weight, wet diapers, breathing or color. Bright Futures advises that in the first 2 weeks infants who sleep more than 4 hours at a time be awakened for feeding, and that infants typically need to be fed 10 to 12 times in 24 hours in the early weeks of lactation. Follow the baby’s provider’s specific advice, which may differ for a baby who is premature or has a medical condition.
5. Keep a log if the parent wants one. A simple feed and diaper log helps conversations with the provider.

Limits and uncertainty

The public health cue lists are consensus-based descriptions, not validated tests, and I did not find trials showing that teaching them improves feeding outcomes. Stress and engagement cues are described in developmental frameworks whose evidence is of low quality or mixed. Cues differ by gestational age, feeding method, culture and individual temperament. Premature or medically fragile infants may show cues differently and need individualized guidance from their care team.

The bottom line

Newborns communicate all the time, and a parent who learns to notice early signs of hunger, fullness, stress and readiness for connection can respond sooner and more calmly. A doula can make those signals visible and then step back, leaving the parent as the expert on their own baby, and calling in the right professional whenever feeding, breathing or responsiveness raises a concern.

Birth & Baby University’s For Doulas page brings together its postpartum doula training, recertification and mentorship for professionals who support families in the newborn weeks. Check that any program meets your certifier’s, employer’s or state’s requirements before you enroll.

This article is for professional education. It is not medical, legal or tax advice. Check the standards of your certifying organization and the rules where you work. For concerns about a baby’s health, contact a pediatric provider or emergency services.

Sources and further reading

• Centers for Disease Control and Prevention. Signs your child is hungry or full (March 2026). Read the source
• American Academy of Pediatrics. Bright Futures: Nutrition, third edition. Read the source
• Hetherington MM, McNally J. Reading appetite cues in infancy: a role for nutrition education. Nestle Nutrition Institute Workshop Series (2019). Read the source
• Brazelton Institute. Newborn Behavioral Observations (NBO) system. Read the source (read October 2026)
• Barlow J, et al. The Neonatal Behavioral Assessment Scale (NBAS) and Newborn Behavioral Observations (NBO) system for supporting caregivers and improving outcomes. Cochrane Database of Systematic Reviews (2018). Read the source
• Kristensen IH, et al. What are the effects of supporting early parenting by newborn behavioral observations (NBO)? A cluster randomised trial. BMC Psychology (2020). Read the source
• The newborn behavioural observations (NBO) system embedded in routine postpartum care in at-risk families in Iceland: a randomised controlled trial. BMC Pregnancy and Childbirth (2025). Read the source

More for professionals: the Professionals Blog.