Sensory Integration Education

Meg Faure (OTR) is an Occupational Therapist with a special interest in babies and toddlers - specifically irritable infants; sleep problems, emotional engagement difficulties and fussy feeding.

The uterus is undisputedly the ultimate environment for the development and nurturing of a fetus. On a physical level, the intrauterine space is the perfect temperature, nutrients are supplied consistently, and the mother’s hormone system regulates all her baby’s physiological functions. The infant’s organs and systems are ready for the real world after approximately 266 ½ days in the womb. However, while the physiological attributes of the womb are obvious, in general, little thought is given to the sensory world of the womb and how the sensory systems adjust after birth.

The sensory systems develop throughout pregnancy and are the architects of the brain’s structure and function. Just as the womb world is the ideal space for the developing baby on a physiological level, it is also the perfect sensory space for the fetus’s neurological development. It is on a neurological level that even the full-term human infant is born too early, compared to other species. Like marsupials, the human infant could benefit from extra time in the womb’s sensory environment. Parents can facilitate optimal brain and emotional development after birth by considering the sensory milieu of the womb.

Fetal sensory development

The fetus begins to develop on a sensory level from the moment of conception. The first sense to develop is the sense of touch, emerging at 3 weeks gestation – before most mothers know they are pregnant. By the twelfth week, the baby can feel and responds to touch on his entire body, with the exception of the top of his head, which remains insensitive until birth (Eliot, 1999). 

The auditory system is completely intact by 20 weeks’ gestation, but it is a few weeks before the nerves conducting sound are functional. At 23 weeks, fetuses respond to loud noise and may jerk or even begin to hiccup after hearing a loud sound (Eliot, 1999). 

Taste buds emerge at 8 weeks and by 13-15 weeks a fetus has taste buds similar to adults. Tastes ingested by the mother flavour the amniotic fluid (Hopson, 1998). While we are not exactly sure when the baby starts to perceive taste, we do know that a baby born prematurely (33 weeks) sucks harder at sweetened nipples and when saccharine is injected into the amniotic fluid in the third trimester the fetus sucks faster (Meisami 1998; Eliot, 1999). 

Smell develops alongside the sense of taste. Since smells are essentially chemicals that are found to be present in amitotic fluid, it stands to reason that fetuses can smell in utero as the chemicals pass from the amniotic fluid onto the olfactory receptors in the nasal cavity. The nasal cavity is protected by a plug of tissue until 28 weeks, but thereafter the fetus will smell and respond to scents (Eliot, 1999). 

The fetus’s tiny eyelids open at 26 weeks and at 6 months we know that babies are sensitive to light in utero. A bright torch light shone and moved across the mother’s pregnant belly, is tracked by the baby at 32 weeks gestation. 

The sense of movement and gravity from the balance (vestibular) system in the ears develops very early and begins to function at five months gestation. Like the sense of hearing and touch, the sense of movement is relatively advanced at birth. 

The world of the womb

Knowing that the sensory systems perceive the intrauterine world by the second and third trimesters, we may wonder what the womb world is like on a sensory level.

The uterine world is devoid of light touch - the predominating touch stimulation in utero is deep pressure touch and the sense of warmth. By the third trimester, the elastic uterus provides constant, deep pressure, like an all-day hug or massage. This tight hug keeps the baby in a flexed position, with pressure on his back and his hands towards the midline. In this position, the fetus can suck his hands and his immature reflexes which are starting to emerge in utero are contained so that he feels secure. The temperature in the womb is always perfect, a temperature we call neutral warmth. Threatening touch (which travels on the Anterolateral system to the brain), such as pain, high or low temperatures and tickle are completely absent during gestation. 

In utero, the overwhelming sounds (about 85 decibels) are the background sounds of the mother’s body. The baby hears the gushes of amniotic fluid and blood flowing in the veins and of course the maternal heartbeat and digestion. These background noises contribute to the constant white noise he hears. The consistent sound of the heartbeat is a particularly soothing sound and babies who are played a beat at the pace of the average heartbeat (72 beats per minute) fall asleep easier and cry half as much after birth. Sounds from the outside world are subdued (55 decibels) but the clearest sound he hears is his mother’s voice, as it is carried not only outside the body but also through her bones in the form of vibrations. Dad’s voice is the second most familiar sound to the baby and it is nice to know that within hours of birth the baby will recognize his father by his voice.

Because all tastes the mother experiences pass into the amniotic fluid, the baby is prepared for the flavours his family eats even while in utero. The preference for sweet tastes is hardwired and babies prefer sweet flavours, swallowing amniotic more vigorously after mum eats something sweet. 

Even though the fetus is interested in and tracks a bright light, the reality is that he is rarely exposed to bright lights and there is very little visual stimulation in utero. In general, the womb world is visually muted and often it’s quite dark. There are no bright colours or contrasting shapes in utero on which the baby can hone his developing visual skills. For this reason, the visual system is relatively immature at birth.

In utero, the baby is buoyed by amniotic fluid and whirls freely in a contained liquid bubble. Since water decreases the weight of an object by 50 times, the fetus has the wonderful sensation of being 1/50th lighter than on earth.  He is lulled by the constant rocking and swaying motion of this gravity-reduced world, gently rocked to sleep. When the lulling movement stops – such as when the mother rests or lies down, babies may become wakeful and busy. During the third trimester, the baby’s vestibular system has matured sufficiently to sense gravity and to turn to the appropriate ‘head down’ position in preparation for birth. 

The fourth trimester

In the last trimester of pregnancy, the baby’s sensory systems are starting to make neural connections and learning begins. However, unlike other mammals, our human infants are born relatively immature. Consider the newborn gazelle, springing across the African veld after the rest of the herd only hours after birth. Her ability to keep up with her mother as the herd moves on is essential for the survival of the species but it is also made possible because of her relative maturity at birth. The human babies like marsupials are born way less mature, with limited ability to act on their world. 

In the last trimester, human babies grow significantly and have a large head compared to other species. This combined with the fact that we walk upright means that our babies have to be born too early (Trevathan, 1987).  The newborn baby is required to begin to regulate four areas: his autonomic system (heartbeat, breathing, colour and digestion), his mood and state (sleep states as well as cry), his motor system (movements), and eventually his attention (The Synactive Theory of Development: Dr Heidelise Als and Dr T. Berry Brazelton). Being immature, it will be some time before the little baby can self-regulate these areas and it becomes the primary role of the parents to regulate these areas. 

The ability to self-regulate, results in a balanced, stable integration of the four subsystems. The synactive theory suggests that parents and caregivers must assist infants to meet self-regulatory goals by regulating the sensory world and assisting the baby to develop the skill of self soothing. This is particularly important during the fourth trimester (the first three months of the newborn’s life). The easiest way to do this is to mimic the womb world.

Creating a gentle womb experience in the first three months (fourth trimester)

During the fourth trimester, encourage parents to reflect on the womb world as the foundation for providing soothing, regulating care to the new baby. Each sensory system provides the opportunity for smoothing the transition from womb to world and assists the baby to maintain homeostasis in the autonomic state, motor and attention systems.

Touch - For nine months the only form of touch the baby has experienced is skin to skin – his naked skin against the uterine walls, the feel of the cord and the sensation of his own touch. In the labour ward, place the baby naked: skin-to-skin on the mother’s chest. Cover both with a blanket or towel to keep the newborn warm. Miraculously, a mother’s chest can increase or decrease by 2 degrees to regulate her baby’s body temperature.  This perfectly natural position is commonly called Kangaroo Mother Care and the mother should aim to ‘kangaroo’ her baby for as many hours as possible in the early days. It is important to know that even babies delivered by caesarean section can be warmed up on their mother’s chest instead of being removed to a clinical incubator. 

Swaddling is very important in the early days as it’s the best way to imitate the tight hug of the womb environment. Swaddling provides deep-touch pressure and also stops little limbs from shooting out due to the startle and moro reflexes (involuntary, jerky movements of the arms and legs away from the middle of the body) which are a common cause of night waking’s in the young baby. A swaddled newborn is a more settled baby and will sleep for longer stretches. For the first nine to twelve weeks, swaddle the baby for all sleeps and when unsettled or colicky. Ensure the baby has some time to kick free of the swaddle when awake. 

It is important to swaddle the baby with his hands near to his face so he can suck on them to self soothe and regulate his body temperature if becoming warm. Swaddling with the hands by the sides is not a good option as your baby will not be able to self soothe or to regulate his temperature. 

Smells - A newborn’s sense of smell is finely tuned at birth. The smells he loves best are the familiar smell of the womb and the sweet smell of breast milk. Do not wash the baby immediately after birth. Wipe him down if he is a little bloody but do not wash off the vernix. There is evidence that unwashed babies bring their hands to their mouths sooner after birth than washed babies. Sucking on his hands is one of the first, really clever and important strategies a baby will use to self-calm and is important in the development of self regulation. Aside from vernix, the soothing smells of mum are the best olfactory input at this stage. In the early days, keep the new baby’s space free from any scents as his smell system is so sensitive. An item of clothing that smells of mum or dad in the cot is comforting.

Sight - Create a visually soothing space by dimming the labour room’s lights and bringing the baby to the mother’s chest, 20-25cm /8 inches from her eyes, which is the perfect distance for focus on her eyes.  Decorate a baby’s room in muted and calm colours and have a light dimmer switch or a nightlight so that the room can be dimmed when the newborn is fractious. A calming sensory space is important as the visual system is a very powerful system for the new baby.  Do not place any toys or mobiles in the cot or crib. The cot must be a calm sleeping space only, not a stimulating play area. For encouraging eye-focus, a few contrasting colour toys or pictures (red, black and white) should be in the room, but keep them near the changing mat where it is appropriate for the baby to be awake and stimulated.

Sounds - The newborn is familiar with and soothed by his mother’s voice. For a period of time, immediately after birth, the newborn will be calm and alert, listening and focusing well.  Encourage parents to talk quietly to their baby to calm him after birth. To assist the baby to regulate his state and fall asleep with ease, use the principles of the intrauterine environment. White noise and womb sounds are calming in the early weeks. Buy or make a recording of white noise (this can be done by recording the vacuum cleaner or radio static) Also available are CD’s of calming music ‘mixed’ with the steady beating of a heart.  

Movement – Babies are best soothed with movement and rocking. In the early days many babies do not settle unless held. A mother may be told she is spoiling her baby or that her baby is manipulating her. The reality is that in the fourth trimester, a baby does not have long term memory that would create expectations for how he needs to be soothed. Rather, the newborn has a sensory need for the womb and the holding and rocking reenacts the womb space for the newborn. A sling therefore is a wonderful tool for soothing fractious newborns and regulating state.

The first three months are a period of enormous transition and adjustment for mother and child. By mimicking the womb world, the parent will assist their baby in regulating its automatic system and state. Swaddling, white noise, and carrying their baby are just three examples of strategies that imitate the womb world and calm babies in the fourth trimester. 

Find out more about Meg Faure here: https://www.megfaure.com

References

Eliot L. Whats going on in there? How the brain and mind develop in the first five years of life Bantam Books 1999

Faure M The Baby Sense Secret Dorling Kindersley (2011)

Faure M & Richardson A Baby Sense Metz Press 2010, rev 2019

Graven S & Browne J Auditory Development in the Fetus and Infant. Newborn & Infant Nursing Reveiws. Volume 8, Issue 4 2008

Hepper P. Unraveling Our Beginnings: On the Embryonic Science of Fetal Psychology. The Psychologist 18 (8) Aug 2005, published by the British Psychological Society.

Hopson J. Fetal Psychology Psychology Today, October 1998

Meisami E. et al Human Olfactory Bulb: Aging of Glomeruli and Mitral Cells and a Search for the Accessory Olfactory Bulb Annals of the New York Academy of Sciences, 1998

Trevathan W. Human birth: An evolutionary perspective. New York: Aldine de Gruyter 1987

Meg Faure (OTR) (www.megfaure.com) is an Occupational Therapist with a special interest in babies and toddlers - specifically irritable infants; sleep problems, emotional engagement difficulties and fussy feeding. Meg is the co-author of Baby Sense and the Sense-series books. Megan is passionate about her work with babies and toddlers and delivers global online services in the parenting space. She lives in Jersey and is married with three children. Meg shares her knowledge on fetal sensory development and the transition from “womb to world”.