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Welcome to the third trimester, where the finish line is in sight but somehow feels like it’s getting farther away with each waddle to the bathroom. If you thought the second trimester was the “honeymoon phase,” consider this the “are we there yet?” phase of pregnancy.
The third trimester spans from week 28 until your baby decides to make their grand entrance (typically between weeks 37 and 42). This is when pregnancy gets real in every sense of the word. Your belly is undeniably large, strangers feel entitled to comment on your size, and simple tasks like putting on socks become legitimate challenges.
But here’s the beautiful part: you’re in the home stretch. Every day brings you closer to meeting your baby. And while these final weeks can be uncomfortable, they’re also filled with nesting energy, exciting preparations, and the knowledge that your body is doing something absolutely incredible.
Let’s break down everything you need to know about surviving—and maybe even enjoying—the third trimester.
In this Article:
- What Exactly Is the Third Trimester?
- What Exactly Is the Third Trimester?
- Third Trimester Symptoms
- Important Third Trimester Appointments and Tests
- Preparing for Labor and Delivery
- Staying Comfortable in the Third Trimester
What Exactly Is the Third Trimester?
The third trimester officially begins at week 28 and continues until your baby is born. That’s typically somewhere between weeks 37 and 42, though 40 weeks is considered “full term.”
Here’s how pregnancy timing breaks down:
- Early term: 37-38 weeks
- Full term: 39-40 weeks
- Late term: 41 weeks
- Post term: 42 weeks and beyond
Most doctors won’t schedule an elective induction before 39 weeks unless there’s a medical reason, as those final weeks are crucial for your baby’s lung and brain development.
How Your Baby Develops During the Third Trimester
Your baby enters the third trimester weighing about 2-2.5 pounds and measuring around 14-15 inches. By birth, they’ll typically weigh between 6 and 9 pounds and measure 19-21 inches long. That’s a lot of growing in just 12 weeks!
Weeks 28-32: The Growth Spurt
During this period, your baby is packing on the pounds. They’re developing layers of fat under their skin, which helps with temperature regulation after birth. That translucent skin from earlier ultrasounds? It’s getting more opaque.
Your baby’s brain is developing rapidly, forming grooves and indentations that allow for more brain tissue. Their bones are fully formed now, though they’re still soft and pliable (which helps during delivery). The only exception is the skull, which remains flexible with soft spots called fontanelles that won’t fully close until after the first year.
Your baby’s eyes can open and close, and they’re starting to develop sleep-wake cycles. They can also see light and dark, which is why shining a flashlight on your belly might get a reaction.
Weeks 33-36: Final Preparations
These weeks are all about refinement. Your baby’s lungs are maturing, producing surfactant—a substance that prevents the air sacs from collapsing and allows them to breathe on their own. This is why babies born at 34 weeks have much better outcomes than those born just a few weeks earlier.
Your baby is also perfecting important reflexes like sucking, swallowing, and grasping. Those adorable newborn reflexes that make them grab your finger? They’re practicing those right now.
If your baby hasn’t already, they’ll likely move into a head-down position during these weeks. Most babies settle into position by week 36, though some stubborn ones wait until the last minute (or stay breech and require special attention).
Weeks 37-40+: Ready to Launch
Your baby is officially full term at 37 weeks and could be born any day now. They’re continuing to gain weight—about half a pound per week—and building up fat stores that will help them maintain body temperature after birth.
The vernix (that white, creamy coating) and lanugo (fine body hair) that covered your baby’s skin are starting to disappear, though some babies are born with remnants of both. Your baby is running out of room, so their movements might feel different—less somersaults, more stretching and pushing.
By 40 weeks, your baby is ready to meet you. If you go past your due date, your doctor will monitor you and your baby closely. Most providers recommend induction by 42 weeks to reduce risks, though many babies decide to arrive on their own before then.
Third Trimester Symptoms: The Good, The Bad, and The “Please Make It Stop”
Real talk: The third trimester can be rough. Your body is working overtime, carrying around extra weight, and preparing for the marathon of labor. Some discomfort is normal, but knowing what to expect can help you cope.
The Physical Challenges
Frequent Urination: Remember thinking you peed a lot in the first trimester? Welcome back to bathroom central. Your growing baby is pressing directly on your bladder, leaving approximately zero storage capacity. You’ll pee before bed, then wake up three times during the night to pee again. It’s glamorous.
Shortness of Breath: Your uterus is now pushing up on your diaphragm, making it harder to take deep breaths. This is completely normal, though it can feel alarming. Most women get some relief in the final weeks when the baby “drops” into the pelvis.
Heartburn and Indigestion: That burning sensation creeping up your throat? Your growing uterus is pushing stomach acid upward, and pregnancy hormones are relaxing the valve that usually keeps it down. Sleeping propped up, eating smaller meals, and avoiding trigger foods can help.
Swelling (Edema): Your feet might look like they belong to someone else. Mild swelling in your feet, ankles, and hands is normal due to extra fluid and reduced circulation. Elevate your feet when possible, stay hydrated, and avoid standing for long periods.
Back Pain: Your growing belly pulls your center of gravity forward, straining your lower back. Your pregnancy hormones are also relaxing your ligaments in preparation for birth, which can make you feel less stable. Prenatal yoga, massage, and a pregnancy support belt can provide relief.
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Hip and Pelvic Pain: Many women experience pain in their hips, groin, or pubic bone as their body prepares for birth. This can be sharp and stabbing or a dull ache. It’s your pelvis loosening and shifting, which is normal but uncomfortable.
Braxton Hicks Contractions: These practice contractions can start as early as the second trimester but typically become more noticeable in the third. They feel like your belly tightening into a hard ball, then releasing. Unlike real labor contractions, they’re irregular and don’t increase in intensity.
Insomnia: Between the constant need to pee, difficulty finding a comfortable position, leg cramps, and your mind racing about everything baby-related, sleep can be elusive. Everyone’s favorite comment—”sleep now before the baby comes”—is both unhelpful and impossible to follow.
Leaky Breasts: You might notice yellowish discharge from your nipples. This is colostrum, the first milk your baby will drink after birth. It can start leaking weeks before delivery and might require nursing pads.
Stretch Marks: These reddish or purplish streaks can appear as your belly rapidly expands. This can be itchy before they arrive but try to moisturize as much as possible. You’re going to need something super moisturizing.. check below for a great pick!
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Pro Tip: Invest in a pregnancy pillow if you haven’t already. The U-shaped or C-shaped body pillows can be game-changers for sleep. You can also use regular pillows—one between your knees, one under your belly, one behind your back. It takes up half the bed, but comfort is priority number one right now.
The Emotional Rollercoaster
Let’s talk about what’s happening in your head, because third-trimester emotions are no joke.
Nesting Instinct: That overwhelming urge to clean baseboards you’ve never cleaned before? To organize the nursery by color-coded labels? That’s nesting, and it’s real. While it’s great to get things ready, try not to exhaust yourself or put yourself in danger climbing on step stools to dust ceiling fans.
Birth Anxiety: As your due date approaches, it’s completely normal to feel anxious about labor and delivery. Will it hurt? (Probably, but you’ll survive.) What if something goes wrong? (You have an entire medical team looking out for you.) Can I actually do this? (Yes, you can, even when you don’t think you can.)
Excitement and Impatience: You’re so close to meeting your baby, and the waiting can feel excruciating, especially once you pass your due date. Every twinge has you wondering, “Is this it?” It’s like waiting for Christmas morning when you were seven, except it lasts for weeks.
Fears About Parenthood: Suddenly worrying about things like sleep schedules, breastfeeding, and how to afford college is normal. You’re about to be responsible for a tiny human, and that’s huge. These fears don’t mean you’ll be a bad parent—they mean you care.
Important Third Trimester Appointments and Tests
Regular Prenatal Visits
Your visits become more frequent in the third trimester. From weeks 28-36, you’ll typically see your provider every two weeks. After 36 weeks, you’ll go weekly until delivery.
These appointments include the usual checks: weight, blood pressure, urine test, fundal height measurement, and listening to the baby’s heartbeat. Your provider will also start checking your cervix around 36-38 weeks to see if it’s starting to dilate or efface.
Group B Strep Test (35-37 Weeks)
Between weeks 35 and 37, you’ll be tested for Group B streptococcus (GBS), a bacteria that about 25% of women carry. It’s harmless to you but can potentially cause serious infection in newborns. The test is quick—just a swab of your vagina and rectum.
If you test positive, you’ll receive antibiotics during labor to protect your baby. It doesn’t mean anything is wrong—it’s just a precaution.
Non-Stress Tests and Biophysical Profiles
If you go past your due date or have certain risk factors, your provider might order additional monitoring. A non-stress test monitors your baby’s heart rate and movement, while a biophysical profile combines ultrasound with a non-stress test to assess your baby’s wellbeing and amniotic fluid levels.
Preparing for Labor and Delivery
The third trimester is when birth preparation shifts from theoretical to practical. Here’s what you need to know and do.
Recognizing True Labor
One of the biggest questions in the third trimester: How will I know when I’m really in labor? Here’s the breakdown:
Braxton Hicks vs. Real Contractions:
- Braxton Hicks are irregular, don’t get stronger, and often stop if you change position or walk around
- Real labor contractions come at regular intervals, get progressively closer together, stronger, and longer
- Real contractions don’t stop with movement or position changes
- Real contractions are often accompanied by other signs like your water breaking or bloody show
Signs of Labor:
- Water breaking: This can be a gush or a trickle. Call your provider immediately if this happens
- Bloody show: Losing your mucus plug, possibly tinged with blood. Labor could be hours or days away
- Regular contractions: Follow the 5-1-1 rule (contractions 5 minutes apart, lasting 1 minute each, for 1 hour) or your provider’s specific instructions
- Back pain: Intense lower back pain that comes in waves
- Nausea or diarrhea: Your body’s way of clearing out before labor
Call Your Doctor Immediately If You Experience:
- Heavy vaginal bleeding (more than spotting)
- Severe abdominal pain
- Decreased fetal movement
- Severe headache with vision changes
- Sudden severe swelling of face, hands, or feet
- Your water breaks, especially if the fluid is greenish or brownish
Creating Your Birth Plan
A birth plan outlines your preferences for labor and delivery. While it’s good to think through your wishes, remember that birth is unpredictable. The best birth plan is a flexible one.
Consider your preferences for:
- Pain management (epidural, natural, other options)
- Movement and positioning during labor
- Who you want in the room
- Interventions (when you’d want them, when you’d prefer to avoid them)
- Immediate postpartum preferences (skin-to-skin, delayed cord clamping, etc.)
- Feeding preferences
Discuss your birth plan with your provider and make sure it’s realistic for your chosen birth location. A birth plan at a hospital might look different from one at a birth center or home birth.
Packing Your Hospital Bag
Pack your hospital bag by 36 weeks, just in case. You’ll actually want three bags: one for labor, one for postpartum, and one for baby. Check out my post on The Ultimate Hospital Bag Checklist!
For Labor:
- Comfortable clothes to labor in (or plan to use hospital gown)
- Socks and slippers
- Hair ties
- Lip balm and lotion
- Phone charger
- Music or comfort items
- Snacks for after delivery
For Postpartum:
- Going-home outfit (think comfortable, second trimester size)
- Nursing bras and shirts
- Toiletries and any medications
- Underwear you don’t mind throwing away (or use hospital disposables)
- Maternity pads
- Nipple cream if breastfeeding
For Baby:
- Car seat (properly installed—you won’t leave without one)
- Going-home outfit in two sizes (newborn and 0-3 months)
- Blanket
- Diapers and wipes (hospitals provide these, but having extras doesn’t hurt)
- Pacifiers if you plan to use them
Pro Tip: Most hospitals provide almost everything you need for recovery—pads, mesh underwear, dermoplast spray, witch hazel pads, ice packs. Don’t overthink the hospital bag. You’ll be there 24-48 hours for vaginal birth, 3-4 days for C-section. You don’t need to pack like you’re going on vacation – trust me, I barely cracked my bad open during my stay BUT there are some things that make you’re stay extra comfy.
Staying Comfortable in the Third Trimester
Comfort becomes a full-time job in the third trimester. Here are strategies that actually help:
Sleep Strategies
- Sleep on your left side (best for circulation, though right side is fine too)
- Use pillows everywhere—between knees, under belly, behind back
- Keep water by your bed for nighttime thirst
- Limit fluids two hours before bed to reduce bathroom trips
- Try a bedtime routine: warm bath, gentle stretching, meditation
- If you can’t sleep, get up and do something relaxing rather than lying there frustrated
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Movement and Exercise
Exercise is still safe and beneficial in the third trimester, with modifications. Walking, swimming, prenatal yoga, and stationary cycling are all great options. Listen to your body, avoid exercises that feel uncomfortable, and stop if you experience dizziness, shortness of breath, or contractions.
Managing Swelling
- Elevate your feet whenever possible
- Avoid standing for long periods
- Stay hydrated (it seems counterintuitive, but it helps)
- Wear comfortable, supportive shoes
- Try compression socks
- Limit sodium intake
Eating for Two (But Not Really)
During the third trimester, you need about 450 extra calories per day—roughly equivalent to a snack. Focus on nutrient-dense foods that give you energy and help your baby grow.
Your stomach has limited space now, so smaller, more frequent meals work better than three large ones. This also helps with heartburn.
The Final Countdown
The third trimester is a paradox. Time moves impossibly slowly day-to-day, but when you look back, it will have flown by. You’ll be simultaneously ready to be done with pregnancy and terrified of what comes next.
This is normal. All of it.
You’re allowed to complain about being uncomfortable. You’re allowed to be excited. You’re allowed to be scared. You’re allowed to feel all the feelings, sometimes all at once.
Your body is doing something extraordinary right now. It’s building a human, preparing to birth that human, and already making exactly what that human will need to survive on the outside. Even when it feels like your body is betraying you with heartburn and swollen feet, it’s actually doing exactly what it’s supposed to do.
Be patient with yourself. Rest when you need to. Accept help when it’s offered. Take photos of your belly, even when you feel huge—you’ll want them later. Spend time with your partner or friends. Enjoy meals you don’t have to share. Binge-watch shows. Sleep in (as much as your bladder allows).
Before you know it, you’ll be holding your baby, and all of this—the discomfort, the waiting, the uncertainty—will fade into memory. Not completely, but enough that you might even consider doing it again someday.
You’re in the final stretch, mama. You’ve got this.
Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with your healthcare provider about your specific situation and any concerns about your pregnancy or labor.
Sources: Information in this article is based on guidelines from the American College of Obstetricians and Gynecologists (ACOG), the Centers for Disease Control and Prevention (CDC), and Mayo Clinic recommendations.