Fourth Trimester

Practising paediatrician and child specialist Dr Harvey Karp believes in many respects human babies are born to soon. Here we explore his theory of the "Fourth Trimester" and his "Cuddle Cure" techniques.

"When the baby comes out, the true umbilical cord is cut forever yet the baby is still, in that second, a foetus.just a foetus one second older," writes Peter Farb in his publication Humankind.

Most expecting parents imagine giving birth to a plump, smiley baby not dissimilar to those gracing the covers of pregnancy magazines. But in reality a newborn enters this world little more than a foetus.

While many other mammals are born with several survival reflexes and instincts enabling them to stand or run the moment they are born, the human baby begins life with only a few, albeit vital, reflexes to ensure survival.

These reflexes are related to breathing, sucking and swallowing.

Compared to other baby animals the human baby is born relatively immature and relies heavily on its parents for survival. In fact in many ways it seems our newborns are born too soon. Perhaps this is because the human infant has no predators and therefore has no immediate need to flee in order to protect itself.

With floppy necks, tiny tremors and irregular breathing human babies appear helpless and vulnerable in their first few months as they adjust to life outside the womb. By the end of the third month, however, the newborn evolves into an infant who is much more aware and capable of response.

When we consider the difference between a minute-old newborn and a three-month-old baby, the rate of growth and development that a human baby undergoes in its first twelve weeks of life is outstanding.

Research has found that the vast majority of human brain growth occurs in the womb, especially during the third trimester, and immediately following birth. In fact as much as 50% of the brain’s Docohexaenoic acid (DHA, an omega-3 fatty acid found in high concentrations in brain tissue believed to be essential to brain development, growth and learning ability) is formed during foetal development while the remaining 50% accumulates during the first year.

These findings inspired American Paediatrician Dr Harvey Karp to research and develop the concept of the "Fourth Trimester", what he refers to as the time between birth and the end of your baby’s third month.

Dr Karp, a paediatric professor at UCLA School of Medicine in California and author of the best-selling book "The Happiest Baby," noticed that most newborns were fussy and foetus-like in comparison two a three month-old baby, illustrating the massive developmental leap babies make during the first three months of life.

"Newborns can’t smile, coo, or even suck their fingers. At birth, they’re really still foetuses and for the next three months they want little more than to be carried, cuddled, and made to feel like they are still in the womb," he says.

"A growing foetus in the womb develops at lightning speed. "Nevertheless, it takes most babies an additional three months to "wake up" and become active partners in the relationship".

So why, you may ask, is it that babies are born at 40 weeks instead of 52 weeks? It seems reasonable to wonder why this period of rapid development does not occur during a fourth trimester in the womb.

Dr Harp believes that the main reason why babies enter this world at 40 weeks is to guarantee a safe delivery. Giving birth at full term is already a tight squeeze – giving birth to a 52-week-old baby would be near impossible.

So it seems that nature ensures early "eviction" for the safety of both mother and baby.

"Womb Service"

On the whole, most infants are able to cope with the transition from womb to outside world. But some find it more difficult than others and need to be held, rocked and suckled for large parts of the day.

This makes sense when we consider the womb environment – the only environment your newborn baby has ever known. Cushioned by the surrounding amniotic fluid, the womb is warm, secure and dark. It is also sensationally noisy with the sound of blood circulating and the placenta pulsating. Food and oxygen is abundant and always on offer. For the most part there is constant movement.

Dr Karp was among the first specialists to put forward the theory that the more we mimic the womb environment the happier our newborns will be. He affectionately calls it "womb service". In more primitive cultures the needs of a newborn are considered differently and mothers spend more time carrying and nursing their babies.

"It’s no coincidence that in culture’s like Bali, where colic is virtually non-existent, parents gives babies much more of a fourth trimester experience than we do," he says.

"Unfortunately, many parents in our culture have been convinced that it’s wrong to cuddle their babies so much. They have been misled into believing that their main job is to teach and educate their newborn".

Dr Karp says it is impossible to spoil a baby in its first four months of life. Training a baby to not be manipulative only becomes imperative during the second six months of his life.

Creating the Womb Environment

During his 25 years of research, Dr Karp observed the reflexes and responses of newborns and identified ways to trigger the calming reflex to help settle disgruntled babies. His five steps simulate the sensations your baby would have experienced whilst growing in the womb.

"You don’t have to be a rocket scientist to be a terrific parent, but there are some little tricks that can help you do your job better," says Dr Karp.

The FIVE "S"s

The Cuddle Cure

Some babies may respond to any one, or a combination of a few, of the following techniques known as the Five "S’s". Using them all in the following order is known as the "Cuddle Cure".


Swaddling stops your baby’s limbs from flailing about. Because rapid movement of arms and legs can lead to over-stimulation, it is best to wrap your newborn so it feels comfortable and secure.
Swaddling wraps or blankets are available in different weights of fabric to cater for varying seasons.

Side/Stomach position

Because a nine-month-old foetus is tightly cushioned in the womb, once they are born they feel lack the physical support. By holding your baby in the side/stomach position this helps your newborn feel safe and in tact by curbing its feeling of falling.


A loud shushing noise in your baby’s ear recreates the sound of the womb environment, which is unbelievably noisy! This is why babies like the sound of a vacuum cleaner.


Small fast rocking movements help activate your baby’s calming reflex and again, mimic the jiggling movement of the fluid-cushioned womb environment.


Offer your breast, finger or pacifier. If your baby seems disinterested in the pacifier, gently tug on it as though you are going to remove it. Your baby will respond by sucking harder.
Further Reading

To find out more about The Fourth Trimester and the Cuddle Cure read "The Happiest Baby" by Dr Harvey Karp, published by Penguin.
ISBN 0-718-14534-8

Give a Comment