At 33 weeks pregnant, you’re entering the home stretch of the third trimester with about seven weeks to go. Your baby is roughly the size of a pineapple, and major developmental milestones are happening fast. Here’s what’s going on with your body, your baby, and what you can start preparing for.
Your Baby’s Development at 33 Weeks
The biggest news at 33 weeks is your baby’s brain. By this point, the brain and nervous system are fully developed, which means your baby can now regulate body temperature, coordinate breathing movements, and process sensory input. You might notice your baby responding more to sounds, light, and even your voice.
The lungs are still maturing. Your baby’s lungs are producing surfactant, a substance that keeps the tiny air sacs in the lungs open so they can absorb oxygen. Full lung maturity typically isn’t reached until around 36 weeks, which is one reason every additional week of pregnancy matters at this stage. If your baby were born now, they’d likely need some breathing support but would have excellent survival odds.
Your baby is also putting on fat rapidly, filling out those wrinkles and building the insulation they’ll need to stay warm after birth. Expect your baby to gain roughly half a pound per week from here until delivery.
Common Symptoms You May Notice
Your body is doing serious work right now, and it’s not subtle. Many of the symptoms at 33 weeks stem from your baby’s increasing size and the pressure that puts on your organs, joints, and pelvis.
Pelvic pressure. You may feel like something heavy is sitting low in your pelvis. This can be a sign your baby has moved into the head-down position, which is exactly where you want them for delivery. The pressure can make walking uncomfortable, especially toward the end of the day.
Braxton Hicks contractions. Your uterus is practicing for labor. These “practice contractions” feel like a tightening across your belly that lasts 20 to 30 seconds before the muscles relax again. They’re painless or mildly uncomfortable, irregular, and don’t get closer together over time. They’re completely normal and nothing to worry about on their own.
Sleep problems. Between the pelvic pressure, the need to urinate frequently, and difficulty finding a comfortable position, insomnia is extremely common at this stage. Side sleeping is recommended during the third trimester because the growing weight of the uterus can compress major blood vessels when you lie on your back, potentially reducing blood flow to your baby. Left-side sleeping is often suggested, though either side is fine. A pillow between your knees or tucked under your belly can take pressure off your hips and lower back.
Other symptoms you may experience include heartburn, shortness of breath (your uterus is pushing up against your diaphragm), swollen ankles, and general fatigue. These are all typical for 33 weeks and tend to intensify as you get closer to your due date.
Tracking Your Baby’s Movements
By 33 weeks, your baby has a noticeable pattern of activity and rest. Paying attention to this pattern is one of the simplest ways to monitor your baby’s well-being between appointments. Most babies are most active in the evening.
To do a kick count, sit with your feet up or lie on your side during a time when your baby is usually active. Count every movement (kicks, jabs, rolls, and pokes) until you reach 10. The specific number of minutes it takes matters less than consistency. What you’re really tracking is whether your baby’s pattern changes. If it suddenly takes much longer than usual to reach 10 movements, or if the movements feel weaker than normal, contact your provider right away.
What Happens at Your Prenatal Visits
During the third trimester, prenatal visits typically shift to every two weeks (and then weekly as you approach your due date). At your 33-week visit, your provider will check your blood pressure and weight, listen to your baby’s heartbeat, and ask about any symptoms like contractions, fluid leaks, or bleeding. They’ll also note your baby’s position and movements.
If you haven’t already been tested for Group B strep, that screening usually happens between weeks 35 and 37. Your provider may also start discussing your birth plan and preferences around this time, so it’s worth thinking through your priorities before your next appointment.
Eating Well in the Third Trimester
You need roughly 300 extra calories per day during pregnancy, bringing the total for most people to about 2,400 calories daily in the third trimester. That’s not a dramatic increase. It’s the equivalent of an extra snack or a slightly larger meal, not eating for two in the literal sense.
Iron and calcium are especially important right now. Your baby is building bone density and blood supply, and your own blood volume is at its peak. Protein supports your baby’s rapid growth. If you’re struggling with heartburn or feeling too full to eat normal-sized meals, smaller, more frequent meals throughout the day can help.
Packing Your Hospital Bag
Thirty-three weeks is a smart time to start putting your hospital bag together. You’re not likely to need it tomorrow, but having it ready removes one source of stress if things move faster than expected.
- Documents: Health insurance card, any pre-registration forms from the hospital, and a photo ID.
- For you: A front-opening nightgown or robe (helpful for breastfeeding), slippers for walking the halls during early labor, toiletries, heavy-flow sanitary pads, and a nursing bra if you plan to breastfeed.
- For baby: An infant car seat with head support (you won’t be allowed to leave without one), a going-home outfit, and a couple of receiving blankets for swaddling.
- For comfort: Your own pillow, phone charger, a change of clothes for your partner, and snacks you actually want to eat.
Warning Signs to Watch For
Most of what you’re feeling at 33 weeks is normal, but some symptoms need immediate attention because they can signal preterm labor or other complications. Call your midwife, doctor, or hospital right away if you experience any of the following:
- Contractions that come more than four times an hour
- Fluid or blood leaking from your vagina
- A persistent, dull ache in your lower back that doesn’t go away with rest
- Stomach cramps that feel like period pain
- Sudden swelling of your hands, feet, or face
- Vision changes like blurriness or double vision
- Your baby stops moving or moves noticeably less than usual
Preterm labor before 37 weeks doesn’t always mean your baby will be born early. Getting to the hospital quickly gives your medical team the best chance of slowing or stopping labor if needed, and of supporting your baby if delivery does happen. Trust your instincts. If something doesn’t feel right, it’s always worth a call.