The world of pregnancy is often split into three separate stages: The first trimester, the second trimester and the third trimester.

After that, you zip off to the hospital or birth center (or a room for your home birth,) and after several grueling hours, you give birth to your sweet little angel. You're taught a few educational lessons by your nurse or doula, handed your swaddled baby, patted on the head, and sent on your merry way feeling both excited and terrified.

While most people only consider childbirth to have three trimesters, we've come to find there is another trimester most people don't know about—it's called the "fourth trimester."

The fourth trimester is comprised of a few essential components and phases, and we're giving you tips on how to best transition yourself and your baby through this next stage.

What exactly is the fourth trimester?

The fourth trimester is the first three months after birth.

Your baby spent nine months in the comfortable home of your belly and is now a tiny little thing in a great big world. So, let's focus on two separate ideas: How to help your baby accommodate during the first three months of their life, and how to heal your body during these next three months of recovery.

The baby's fourth trimester

In the fourth trimester, your baby is going through a massive environment transition.

During the nine months of pregnancy, your baby was cradled in its amniotic sac and fluid. Now that they're here in the world, that environment is gone—and that takes some getting used to.

To help your newborn transition into this new environment in the fourth trimester, you can recreate feelings of their 'prior home.'

Recreating your baby's belly bungalow doesn't mean sticking your baby in a bath 24/7, but it does mean we can evoke the same comfort and security our baby was used to feeling in the womb.

Here are two ways to help your baby transition to their new environment:

1. Skin-to-skin contact

Immediately after birth, we are hopefully handed our babies and told to place them on our bare skin. This skin-to-skin contact calms the baby with our skin's warmth and familiarizes our baby with the smell of our skin and the sound of our voice.

2. Swaddling

Babies are used to being enveloped by fluid and your snug uterus, so having to adjust to this open space we call the world is a drastic change. Swaddling the baby in a cloth can help the baby feel as if they have more security. It is important to learn the proper technique for swaddling, so your baby feels comforted but not restricted. Ask your nurse to show you before you leave your birthplace, or try a swaddle device that helps take some of the guesswork out of it.

Your baby's development during the fourth trimester

During the first three months postpartum, your baby will be experiencing a ton of change. This change is often expressed in three ways: crying, sleeping and eating. Knowing what you can anticipate during your baby's fourth trimester will better equip you on how to handle their changes.

Here are four newborn developmental changes to anticipate during the fourth trimester:

1. Crying

Crying is said to escalate around five to six weeks and typically lessens around three months. Keep in mind that crying is your baby's only form of communication. Although you should keep an eye out to make sure nothing is significantly wrong with the baby (and remember to call your pediatrician for any questions), you can also take comfort in knowing that your newborn will cry a lot in the fourth trimester.

2. Sleeping

Babies all vary in their sleep schedules. In the first two months, babies are not able to tell the difference between day and night. During the first week, babies will typically sleep 16-18 hours throughout the day, and as they get older, they will lessen the amount of time they need to sleep.

3. Eating

Newborns typically feed once every two to three hours because their stomachs are small and digest quickly. Over the course of time, your baby will feed less frequently because their stomachs will grow and will be able to stay fuller for a longer duration of time.

4. Senses

In the womb, your baby develops their senses, but everything is a bit muted. But during the fourth trimester, their senses start to sharpen.

  • Vision: At birth, your baby's vision is blurred. As time goes on, your baby will slowly open their eyes more and start to recognize shapes until they are fully able to see. Take note of your baby's alertness. As your baby gets older, they will look around more and place focus on different things they are able to recognize.
  • Smell: We are often told to hold our baby against our bare skin during the fourth trimester to accustom our baby to our smell. This especially comes into play if you choose to breastfeed your baby. When it's time to feed, even if our baby can't see fully, they are able to recognize our scent and can search for the breast to begin feeding.
  • Hearing: It turns out that playing classical music for your baby in the womb wasn't a moot effort! Your baby is able to hear during pregnancy and has vaguely familiarized themselves with the sound of our voice. After delivery, your baby is introduced to a world full of sounds. Crying may occur if the baby is overwhelmed with senses, especially sound. Although we don't need to keep our baby in a chamber of silence, we should be aware of the surrounding noise to keep our baby comfortable.

Mama's fourth trimester

Talk about massive transitions. While your baby is adjusting to being in this world, you are adjusting to being a mother! Here is what you can anticipate and how to help yourself through this massive transformation.

Physical transition

The changes your body endures during pregnancy are nothing short of a miracle. The mere fact that women's bellies expand in order to house their little cohabitant is astounding. But these changes and the physical endurance we need to give birth take a serious toll on our bodies. For mothers, the fourth trimester should be dedicated to the physical recovery of your body.

Pelvic floor therapists specialize in helping women assess and strengthen their abdomen and pelvic region after birth. While typically, the human body is resilient and returns to its former functionality, sometimes, this restoration period doesn't happen quite as seamlessly as we'd like it. If you are experiencing incontinence, instability or back pain, these may all be signs that your pelvic region needs to be examined.

The same thing goes for your abdomen.

During pregnancy, the tissues expand, and after delivery, these tissues will typically return to their normal location. However, in certain cases, diastasis recti, or a separation in the abdomen tissues, will leave you with a protruding belly. If, after several months post-delivery, you still have a larger-than-normal belly, seek out a pelvic floor therapist or women's health provider and have them measure the width of separation occurring in your abdominal region. They should be able to tell you what is normal or not and recommend exercises and massages for more efficient recovery.

Postpartum nutrition

The fourth trimester should be a time when mothers focus on the healing of their bodies through proper diet and nutrition. As we've discussed, the process of pregnancy and giving birth is extremely taxing, and while our focus usually defaults to our newborn during this time, we also need to make ourselves a priority, especially when it comes to nutrition.

During the fourth trimester, mothers should emphasize the following three aspects of their nutrition:

1. Boosting serotonin

Postpartum depression is the most susceptible during the fourth trimester because your body is trying to rebalance its hormones and is likely sleep-deprived. There are some foods that are believed to naturally boost your serotonin levels by incorporating foods that contain tryptophan and vitamin B6 into your diet. Foods like eggs (specifically the yolks), salmon, pineapple, tofu, turkey, and nuts can all naturally help you feel happier and more energized. This being said, if you have any concerns about your mental health, seek medical treatment or therapy right away.

2. Regulating the digestive system

Unfortunately, constipation and hemorrhoids are common during the fourth trimester. To regulate your digestion, stay hydrated and eat enough fiber. Foods like flaxseed, berries, oatmeal, ripe bananas, and fermented foods (like yogurt, kimchi, and sauerkraut) can help regulate the digestive tract.

3. Finding a wholesome nutrition supplement

During the fourth trimester, healing our bodies through the vitamins, minerals and nutrients, we receive through food is essential. During birth, women have significant blood loss, which is why maintaining healthy levels of iron is so important. Having efficient protein is also a must in order to rebuild our muscles and overall strength. A good way to ensure we reach our daily nutrition is to find a clean, healthy nutritional supplement. You should keep taking your prenatal vitamin, and consider speaking with your provider about additional recommendations for your specific needs.