What! There's a Fourth Trimester for Babies

By Nicole Cassey, Bubbaroo - Helping Babies Sleep

Most parents think that 3 trimesters of pregnancy is enough! But wait there’s more! Once your baby is born, people often refer to the first 12 weeks of life as the Fourth Trimester. What does it mean? Find out how you can help your baby adjust to life outside the womb.

What is the Fourth Trimester?

As your pregnancy progressed, it was broken down into trimesters. Your baby has spent 3 trimesters inside the womb and experts now say that the first 3 months outside the womb could be considered the Fourth trimester. The Fourth trimester is basically letting your baby adjust to the outside world gently, warmly, snugly and closely.

It helps to understand the Fourth Trimester theory, if you can imagine what life was like for your baby inside the womb, especially during the final trimester - warm, dark, cosy, constantly fed and rocked by your movements and comforted by the sound of your heartbeat. Birthing into the world, full of new stimuli and experiences is a real shock to your baby. There is a lot to adjust to earth-side. Babies cry because they are in pain, hungry, cold, hot or tired - in utero these things weren't an issue. A baby won't stop crying until their needs are met, so our job as parents is to meet their needs.

American Paediatrician and author of “The Happiest Baby on the Block” Harvey Karp believes the best way to calm your newborn and get them to sleep is by re-creating the noises, movement, and snug environment of the womb.

B. Karp, is also an assistant professor of paediatrics at the University of Southern California School of Medicine and describes the first few months after birth as the fourth trimester. "Babies are out of the womb”, he says, “but they're really not ready for our world. Most babies doze much better when surrounded by some of the soothing sensations they enjoyed in the womb. These sensations work so well because they turn on a calming reflex – an off-switch for crying and on-switch for sleep that all babies are born with."

Think of the fourth trimester as helping your baby adjust to their new world. You could try the following suggestions to help your newborn baby transition to the outside world and also for you to adjust to life as a new parent to your unique, one of a kind baby.

Skin Contact

Offering lots of cuddles and contact especially skin to skin contact. Babies love your natural smell and it is very comforting for them. It is also a great way for baby to bond with Dad too. Skin to skin contact is a really beautiful thing especially after birth and can be very beneficial for your baby. The first moments after birth are a once in a lifetime experience but remember skin to skin contact can be repeated once you’re home from hospital too.


Whilst skin to skin contact is ideal in the early days, it’s not physically possible all day and night long. When your baby needs to be put down, a swaddle can help recreate that comfort feeling experienced in the womb. A swaddle helps settle your baby’s startle or moro reflex and can help your baby to sleep soundly and safely in the Fourth Trimester.

Calming Position

The back or supine position is the ONLY safe position for your baby when sleeping. If you would like to calm your baby whilst they’re awake in your arms then you could try the “tiger in a tree” hold where baby is positioned on their tummy over your forearm or hold your baby over your shoulder and rub their back.


Babies enjoy movement - that's why the car and the pram can easily put them to sleep. It is very normal for a baby to protest if they are put down to sleep in a flat motionless surface like a cot or bassinet - it takes time to learn about the new environment. Generations have used rockers and baby carriers to help babies adjust to the life outside the womb. A sling or baby carrier keeps baby close to you and your hands are free to do other things.

Sleeping Close By

Having your baby sleep nearby during the first 6 -12 months of life can really comfort your baby. Since they have become accustomed to being close to you, keeping your baby nearby for sleep offers baby more opportunity to be close to you. You may find that you sleep better too and baby will feel reassured knowing that you are nearby. Room sharing has also been shown to lower the risk of SUDI (Sudden Infant Death Syndrome).

Bath Time

Bath time can be a very important sensation for baby to simulate the in- utero environment. The bath water is warm and provides the watery floaty feel your baby had in utero. A bath before bed will become an important part of your baby’s bed-time routine, as a warm bath makes baby very relaxed as they wind down for bed. Even better if Mum or Dad hop in the big bath whilst holding baby so there is skin to skin contact also!

Adjusting Your Expectations

Letting go of schedules - your new baby is not a programmable device. You need to tune into their needs. You cannot 'spoil' a newborn baby - they need as much attention as you can give them. 

Being so close and offering so much “womb service” to your baby can be exhausting and we fully acknowledge that the early days of parenting can be exhausting. We've been there and can totally empathise.

Ask for Help

Try to share the load or ask for help where you can, especially in the Fourth Trimester. Don’t be too hard on yourself, you’re learning too. Perhaps if a friend or relative comes to visit, ask if they would mind watching your baby while you go out for a walk on your own, take a day time nap or sit in the backyard and have “time out”. Perhaps your partner can care for the baby while you have some “me time”.

If you don’t have any friends or family nearby to help, you may wish to employ a post-natal doula or baby expert if this is within your means. A post-natal doula or other baby expert can help with the care of the baby, breastfeeding issues and generally assisting your recovery by offering practical support.

Share the Load

You and your partner could try to take turns settling the baby. It’s a great opportunity for dads to learn how to settle your baby and also bond with your baby. Your baby will learn to settle with both parents - this is a good idea because going forward your baby won’t rely solely on you for settling and comfort.

The Fourth trimester is a time of great learning, adjustment, recovery and getting to know your newborn baby’s personality. Believe me it will pass in the blink of an eye so enjoy those precious moments with your baby when they're so small and completely dependent on you!

Note: The views and advice expressed on this blog post are those of the author and are not representative of the Pregnancy Babies & Children's Expo.

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