Everyday stress in babies: What research suggests about keeping babies calm and happy

© 2009 Gwen Dewar, Ph.D., all rights reserved

We know that neglect and abuse are terrible stressors.

And we also know that the babies with the healthiest stress response systems have parents who are sensitive and responsive (Blair et al 2006).

But let’s assume a baby has loving, sensitive parents. There are still questions about everyday stress:

• Should you pick the baby up and rock her, talk to her, gaze into her eyes? Or is that too disruptive?

• Should I dress the baby up? Or are fewer clothes better, so he can experience skin-to-skin contact with his caregivers? What about baby massage?

• Is it better to change that diaper now—even though your newborn is asleep?

Of course, there isn’t any one answer to these questions. Each baby—and each situation—is different. But experimental research helps us understand the big picture about babies in stress.

Multi-sensory stimulation

But studies suggest that multi-sensory stimulation--touching, gazing, talking, and rocking babies all at once--can reduce stress in babies.

One recent study presented newborns with one of three treatments (White-Traut et al 2009). Half an hour before feeding, each baby was given either

• 15 minutes of tactile-only stimulation (in which the baby was stroked without being picked up, gazed at, and talked to)

• 15 minutes of multisensory stimulation (in which the baby was touched, talked to, gazed at, and rocked)

OR

• No stimulation (the control group)

Researchers also tested the infants’ levels of cortisol—a stress hormone—both before and after the intervention. Guess who experienced the largest rise in cortisol? It was the babies in the tactile-only group. The babies in the control group experienced an intermediate rise of cortisol.

And the least-stressed babies--as measured by their cortisol reactivity--were those who’d been given the multi-sensory stimulation.

Touch and skin-to-skin contact

But normal, affectionate touching--which is accompanied by other modes of communication--is a different thing entirely. A large body of experiments on humans and other animals show that infants benefit from frequent, affectionate handling and skin-to-skin contact.

Stroke a baby rat, and it produces endogenous opiods--natural pain-relievers and sedatives (Roth and Sullivan 2006). It also produces more oxytocin, a hormone that counteracts the effects of stress (Stock and Uvnas-Moberg 1988).

The effects might last a lifetime, too. One recent study reports that rats who received less physical contact from their mothers went on to develop fewer oxytocin neurons in the hypothalamus (Todeschin et al 2009).

Nobody is going to perform a similar experiment on humans. But there are studies suggesting that touch--including skin-to-skin contact--is an important way to reduce stress in babies.

When newborns were subjected to a painful medical procedure--a heel prick—they showed fewer signs of distress if they were held naked against their mothers’ bare skin (Gray et al 2000). And other studies suggest that infant massage can reduce stress hormone levels (Underdown et al 2006).

Letting babies sleep (even with a wet diaper)

Experimental studies suggest that newborns respond to diaper changes as if they are painful (Mörelius et al 2006). And if you worry he’ll wake up anyway, it’s not especially likely: In another experiment, researchers injected the diapers of sleeping babies with water to see if the intervention would make babies awaken. It didn’t (Zotter et al 2007).

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References: Stress in babies

Mörelius E, Hellström-Westas L, Carlén C, Norman E, and Nelson N. 2006. Is a nappy change stressful to neonates? Early Hum Dev. 82(10):669-76.

Roth TL and Sullivan RM. 2006. Examining the role of endogenous opioids in learned odor-stroke associations in infant rats. Dev Psychobiol. 48(1):71-8

Stock S and Uvnäs-Moberg K. 1998. Increased plasma levels of oxytocin in response to afferent electrical stimulation of the sciatic and vagal nerves and in response to touch and pinch in anaesthetized rats. Acta Physiol Scand.132(1):29-34.

Todeschin AS, Winkelmann-Duarte EC, Jacob MH, Aranda BC, Jacobs S, Fernandes MC, Ribeiro MF, Sanvitto GL, and Lucion AB. 2009. Effects of neonatal handling on social memory, social interaction, and number of oxytocin and vasopressin neurons in rats. Horm Behav. 2009 Mar 24. [Epub ahead of print]

Underdown A, Barlow J, Chung V, and Stewart-Brown S. 2006. Massage intervention for promoting mental and physical health in infants aged under six months. Cochrane Database Syst Rev. 18;(4):CD005038.

White-Traut RC, Schwertz D, McFarlin B, and Kogan J. 2009. Salivary cortisol and behavioral state responses of healthy newborn infants to tactile-only and multisensory interventions. J Obstet Gynecol Neonatal Nurs. 38(1):22-34.

Zotter H, Urlesberger B, Pichler G, Mueller W, and Kerbl R. 2007. Do wet diapers induce arousals in sleeping infants? Acta Paediatr. 96(3):452-3.

Content last modified 5/09