The Fourth Trimester: What Do New Parents Need to Know About Their Crying Baby?

Do you know why your crying baby cries?

If you’re pregnant (or already have your little one), I bet that you’d do (or did) everything to make sure your little in-utero baby was safe, healthy and growing as they should. You take your prenatal vitamins and try to eat healthy foods. You’d get enough rest and read up on all the things to avoid while your baby is still developing. If you have a surrogate or are adopting, you’d hope that the birth parent was paying attention to all those things too.

Why? Because you know that it takes about 40 weeks to grow a healthy baby. From the size of an apple at 14 weeks, to a butternut squash at 29 weeks, to a mini watermelon at 39 weeks, your baby has been getting all the vital nutrients and care they need, in utero.

But what if I told you that the first three months of a baby’s life has more in common with what came before than what will follow.

The first three months of life, also known as the fourth trimester, is an “outside-the-uterus period of intense development that is an extension of the work begun during the first nine months,” says Susan Brink, author of The Fourth Trimester.

A newborn human is not so much a baby as a final-phase fetus living through a time of transition as he gives up the comforts of the uterus and gradually adjusts to the wonders and challenges of the world.

Susan Brink

I often hear the questions of frustrated new parents. “Why does my baby cry when I put them down in their crib?” or “Why does my baby wake up as soon as they’re no longer being held?” and “What do I do with my crying baby when I know they’ve been fed, cleaned and rested?”

Up until birth, all of your baby’s needs were automatically met. They didn’t need to indicate what they were. In utero, your baby was safe, fed, kept warm, soothed by your motion and cradled in amniotic fluid. After birth, all that is gone in an instant. Now, your baby must breathe air and cry to be fed; whimper to get warm; mewl to get cool; sob to be soothed; whine to be cleaned and bawl to be close to you. And it’s our job to figure out what all these cries mean.

During this intense fourth trimester, baby and parent need to be physically close. This allows the baby to get their needs met as soon as possible and for the parent to “learn” their baby’s needs, efficiently.

Each time a parent or loving caretaker responds to a baby’s cry, the infant’s required neurological wiring is one step closer to being complete. This brain development, whether met with a loving response or not, is happening all the time. Therefore, responding to a crying baby matters.

Tired, frustrated parents may feel that they’re setting a precedent for future behavior by tending to their babies with every cry. Or they may feel manipulated by their baby because they know that their physical needs have already been met. And still, they cry. They needn’t worry. The only reason newborns continue to cry is because of biology. They cry to survive. Says Brink,

The first three months of a baby’s life are not about training him to be an independent person. That comes later. The first months are all about helping him to shift from depending on the comfort of the womb to adjusting to the world he’s been born into. What he needs to know is that when he is distressed, someone who cares about him is there – even if his problem is inexplicable.

Susan Brink

Of course, if you’re worried that something just doesn’t feel right, listen to your gut and seek out medical attention.

Sometimes the hardest time for a parent is just being with their child when all they can do is cry. (This is true at any age.) But don’t worry because this, too, shall pass.