What is the Fourth Trimester?


We all know about the three “Trimesters” of pregnancy. But have you heard of the “fourth trimester?” It is a term coined by Dr. Harvey Karp for the first three months of your baby’s life. Karp believed that babies are born “too early,” and for the first three months of life, babies need extra attention from their human caretakers, especially Mama!

If you’ve had a baby, you know what this “fourth trimester” is all about, even if the term is new to you. Your baby doesn’t want to be in a pack and play or crib; your baby doesn’t want to swing in the swing; your baby doesn’t want to be in a bassinet. Your baby wants you. Just you. He/she wants cuddling, skin to skin, nearly 24/7. If you’re nursing, your baby wants to nurse multiple times a day, much more than the 3-6 times we eat per day. And it’s natural and normal! Your baby was just removed from a warm, safe, and self-sustaining environment in your uterus … and now – WHAM! Your baby is, for the first time, experiencing:



*bright lights in his/her eyes

*feeling left alone

*being still

Just imagine if we were thrown into an unknown environment, different from everything we’ve experienced!

So, as parents, we’re exhausted. We love our baby, of course, but it’s tiring to constantly hold your baby. Especially when we hear comments from loved ones…

“My baby slept through the night at two weeks in a crib.”

“I never co-slept. My babies were always independent.”

“I just put my baby in a swing after he was a week old so I could get chores done.”

“You’re going to spoil your baby by holding him all the time.” (This one is SO not true, by the way!)

Et cetera. Et Cetera.

It can help ease your mind to hear that it’s actually normal for your baby to want to be held constantly. Babies need your comfort! Not much can soothe your baby like you can by just cuddling, especially skin to skin. There are, however, a few things that can help besides cuddling when your little one is having a fussy moment. Dr. Karp discussed these behaviors and termed them the “5 S’s”:

1. Swaddle. The “safe sleep” swaddlers are awesome for this, as the velcro helps keep them in place and decreases the chance of suffocation and SIDS. Babies often feel like they are back in their “home” (mom’s belly!) when swaddled. My favorite kind: HALO Sleep Sack

2. Side/Stomach position. This refers to holding an awake baby on his or her side or tummy, and should not be used for sleeping.

3. Shush. This is making a loud “shushing” sound with your mouth, to help soothe baby. Your baby is used to a loud “whooshing” sound in mom’s belly for months and months, and silence can be very scary. Making a loud “shushing” sound near baby’s ears can help soothe him/her as baby remembers that comforting sound from the past few months before birth.

4. Swing. Not the kind you plug in, however. Karp recommends holding baby and making a “swing” with your arms, by moving baby less than an inch, back and forth. This is a gentle motion, similar to the motion baby feels inside the uterus when mom was walking around during pregnancy.

5. Suck. If not breastfeeding, definitely try a pacifier! If you are breastfeeding, make sure it’s well established and things are going well with latching and weight gain, and then you can also try a pacifier. Or…just breastfeed when your baby is fussy. It may very likely do the trick as well!

Karp has written some amazing books about parenting and babies. I highly recommend his book, The Happiest Baby on the Block, which discusses the 5 S’s in more detail, along with lots of other good info and advice for getting through your fourth trimester. (Brown Co. Library does have a couple copies; in case you would rather not purchase it. The libraries also have an accompanying DVD.)


Best of luck to all you new mommas out there. Remember that even on those days when you have no energy and are more exhausted than you ever imagined, your baby loves you more than anything and you’re doing a fabulous job.  Keep it up!

For more info, check out:



the fourth trimester infographic

Disclaimer: The Content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. I’m just a mom sharing what worked for us and resources. Always seek the advice of your physician or other qualified health provider with any questions you may have.