Science says pregnancy has three trimesters, but there are actually four. Ask any new mom, and she’ll tell you the story doesn’t end when the baby is born. The weeks and months that follow, often called the fourth trimester, bring dramatic shifts physically, emotionally and mentally for the entire family.

“It’s a time of massive transition,” says Kate Russell, an obstetrics educator and lactation consultant with Tidelands Health. “Depending on who you ask, the fourth trimester can even extend through the whole first year postpartum. So much happens after you leave the hospital.”

Alongside the joy of welcoming a new baby comes sleep deprivation, hormonal changes, feeding challenges, emotional swings and a brand‑new family dynamic.

One of the first outings you and your baby will have after coming home from the hospital is a visit to the pediatrician. This appointment usually takes place between one and three days after leaving the hospital.

Mental health monitoring also starts right away.

“We watch closely for postpartum depression in the hospital,” says Tory Kiningham, a certified nurse midwife at Tidelands Health. “Sometimes we bring individuals back in the first week or two to monitor those symptoms as well.”

Many new parents don’t realize how dramatic the hormonal shift after birth really is.

“The biggest change actually happens as soon as the placenta is delivered,” Russell says. “That’s when you get this big surge of hormones that flips the switch for lactation to begin.”

During pregnancy, the placenta produces very high levels of progesterone and estrogen. These hormones support pregnancy, maintain the uterine lining and suppress milk production until birth.

Once the placenta is out:

• Progesterone and estrogen levels drop dramatically, almost instantly. Some studies show progesterone falls back to pre‑pregnancy levels within 24 hours.
• This sudden crash is one of the major triggers for baby blues, emotional lability and that “wave of overwhelm” many parents feel around days 3–5.
• At the same time, the drop in pregnancy hormones allows prolactin (the milk‑making hormone) and oxytocin (the bonding and let‑down hormone) to rise and do their jobs.

These hormones work together to help the uterus contract, initiate breast milk production and support bonding, but they can also contribute to mood swings, tearfulness and heightened sensitivity in the early days.

Baby blues are extremely common and typically tied to this dramatic hormonal shift. But they are short‑lived, usually improving on their own within two weeks.

When symptoms last longer than two weeks, or intensify instead of easing, that’s when providers begin looking more closely for postpartum depression (PPD) or postpartum anxiety (PPA).

PPD/PPA symptoms may include:

• Persistent sadness or hopelessness
• Constant worry or racing thoughts
• Feeling disconnected from the baby
• Loss of interest in things you used to enjoy
• Difficulty sleeping even when the baby is asleep
• Feeling unable to care for yourself or your baby

“You can have no history of mental health struggles, and it can still hit you hard,” Kiningham says. “Everyone exhibits depression or anxiety a little differently, which is why keeping postpartum appointments is so important.”

Partners and support people play a critical role, too.

“One of the best tools for a support person is knowing what your significant other’s baseline is,” Russell says. “Sometimes the people around us see changes before we do.”

If something feels “off,” it’s always worth reaching out.

Mom’s IMPACTT, offered by MUSC Health, is a mental health and substance use disorder resource and referral program for people who are pregnant or within 12 months postpartum, and any health care provider caring for a pregnant or postpartum person.

Patients can be connected to resources and treatment, Monday through Friday from 8 a.m. to 5 p.m. Calls outside this window will be returned the next business day.

If you think you have signs or symptoms of PPD or PPA, call your health care provider right away. There are things you and your provider can do to help you feel better. If you’re worried about hurting yourself or your baby, call 911.

Between days 5 and 7 postpartum, most breastfeeding parents see dramatic changes in milk supply.

“You’ll feel your mature milk coming in,” Russell says. “Good nutrition, hydration and breast care are huge in those early days.”

But breastfeeding is not always intuitive.

Latching issues, tongue ties, underproduction and exhaustion can complicate feeding, but help is available. Tidelands Health lactation consultants follow up soon after discharge, and Russell stresses that no one should struggle alone.

“People ask me all the time what they should eat to support milk supply,” she says. “Balanced meals with protein are best. Oatmeal can help, but you don’t need expensive lactation cookies. Homemade versions work just as well.”

And you probably figured stress can also decrease supply, which is why new moms should lean on their support person for help.

Sleep when you can.

“Babies aren’t supposed to sleep through the night at first,” she says. “They eat eight to 12 times in 24 hours. So, parents need naps when they can get them.”

Nutrition and hydration also support healing and milk supply. Russell recommends prepping meals before delivery or accepting help from visitors.

“If someone wants to bring you a meal, that’s an amazing gift,” she says.

As for postpartum exercise, most people need to wait for medical clearance at the six‑week checkup. Light walking is almost always fine, encouraged, even.

“Movement is important,” Kiningham says. “We don’t want you bedbound. A light stroll around the neighborhood is definitely OK for both you and baby.”

The fourth trimester doesn’t end once you hit the six‑week checkup. While many physical changes stabilize by that point, emotional and mental recovery can take longer, and that’s completely normal.

In the months that follow, parents may continue to experience:

• Shifts in sleep patterns as baby grows
• Adjusting to breastfeeding, pumping or formula feeding routines
• Returning to work and navigating feeding schedules
• Ongoing hormonal adjustments
• Evolving family dynamics and identity changes

This period is full of learning curves, milestones, and transitions, not just for the baby, but for the entire household.

As Russell puts it: “You’re learning. Your baby is learning. And you don’t have to figure it out alone.”

Whether you’re navigating sleep deprivation, breastfeeding challenges, mood changes or simply adjusting to your new normal, reaching out for help is one of the strongest things you can do.

If you’re struggling with feeding, including pain, latch issues, low supply, oversupply or simply feeling unsure, the lactation consultants at Tidelands Health are ready to support you.

Lactation services offered by Tidelands Health are free to the community, regardless of where you delivered. You can get in touch by calling 843-625-8180.