The third trimester stretches from week 28 to around week 40, and it’s when your body, your baby, and your to-do list all accelerate at once. This is the time to prepare physically for labor, stay on top of more frequent prenatal visits, set up your home for a newborn, and learn to recognize the signals that mean it’s time to head to the hospital. Here’s a practical breakdown of what to focus on and when.
Keep Up With More Frequent Prenatal Visits
Your appointment schedule picks up noticeably in the third trimester. From weeks 28 through 36, you’ll typically see your provider twice a month. After 36 weeks, visits become weekly until delivery. These visits aren’t just routine check-ins. Your provider is monitoring your blood pressure, your baby’s position, and your cervix as you get closer to labor.
Two key tests happen during this window. If you haven’t already had your glucose screening (usually done around weeks 26 to 28), it may carry into early third trimester. This checks for gestational diabetes. Then, between weeks 36 and 37, you’ll be screened for Group B strep, a type of bacteria that’s harmless to you but can cause serious infection in a newborn during delivery. The test is a simple swab of the vagina and rectum, and if you test positive, you’ll receive antibiotics during labor.
Get Your Tdap Vaccine
The CDC recommends getting the Tdap vaccine between weeks 27 and 36 of each pregnancy, ideally in the earlier part of that window. This protects your baby against whooping cough before they’re old enough for their own vaccinations. Getting vaccinated in this timeframe lowers the risk of whooping cough in babies younger than 2 months by 78%. Your body produces antibodies that cross the placenta and give your newborn passive immunity during those vulnerable first weeks.
Track Your Baby’s Movement
Starting around 28 weeks, it’s a good idea to pay attention to how and when your baby moves. The most common method is to note how long it takes to feel 10 movements. Pick a time when your baby is usually active, start a timer, and count kicks, rolls, and jabs until you reach 10. There’s no universal time limit that applies to every baby. What matters most is your baby’s individual pattern.
Every baby has a different baseline. Some reach 10 movements in 15 minutes, others take longer. The important thing isn’t hitting a specific number in a specific window. It’s recognizing a change from what’s normal for your baby. If your baby is noticeably less active than usual, or if the pattern shifts significantly, go to the hospital for evaluation right away, even if it’s after hours.
Prepare Your Body for Labor
Starting around week 34 or 35, you can begin perineal massage. This involves gently stretching the tissue between the vaginal opening and the rectum, which is the area most likely to tear during a vaginal delivery. Doing this once or twice a week through the end of pregnancy can reduce your chance of tearing and lower the likelihood of needing an episiotomy (a surgical cut to widen the opening during delivery). More than twice a week isn’t recommended and doesn’t add benefit.
This is also a good time to practice breathing techniques or positions you’ve learned in a birth class. If you haven’t taken one yet, many hospitals and birthing centers offer condensed weekend courses in the third trimester. Even a basic understanding of what happens during each stage of labor can reduce anxiety when the time comes.
Eat for the Final Stretch
Your calorie needs increase in the third trimester, but not by as much as you might think. Most normal-weight pregnant women need about 2,400 calories per day in these final months, roughly 300 more per day than before pregnancy. Focus those extra calories on nutrient-dense foods: protein for your baby’s rapid growth, iron-rich foods to support your expanding blood volume, and calcium for bone development. Constipation is common in the third trimester as hormones slow your digestion, so fiber and plenty of water help more than you’d expect.
Know the Signs of Labor
True labor has three hallmarks: contractions that come at regular intervals, last longer over time, and grow stronger. Early labor, when the cervix dilates to about 6 centimeters, typically lasts 6 to 12 hours. Active labor, when dilation reaches 10 centimeters and you may feel the urge to push, usually lasts 4 to 8 hours.
The standard guidance is to call your provider or the hospital labor floor once contractions are coming every five minutes and have held that pattern for at least one hour. Before that point, early labor is generally safe to manage at home with rest, hydration, and position changes. False labor (Braxton Hicks contractions) tends to be irregular, doesn’t intensify, and often stops when you change positions or walk around.
Watch for Warning Signs
Preeclampsia is a serious pregnancy complication that most commonly appears in the third trimester. Its defining feature is high blood pressure, often accompanied by signs of kidney or organ stress. Symptoms to watch for include severe headaches that don’t respond to rest or fluids, changes in vision such as blurriness, light sensitivity, or temporary vision loss, severe pain in the upper belly, and sudden swelling in the face or hands. Some swelling is normal in pregnancy, but a rapid onset is different.
If you experience any of these symptoms, contact your provider immediately or go to an emergency room. Preeclampsia can escalate quickly, and early detection makes a significant difference in outcomes for both you and your baby.
Set Up the Car Seat
You’ll need a rear-facing infant car seat installed before the hospital will discharge you. Install it using either the LATCH system (lower anchors and tethers built into most vehicles) or the vehicle’s seat belt threaded through the car seat as described in the manual. Once installed, the seat should not move more than one inch side to side or front to back. Never place a rear-facing car seat in front of an active airbag, and check whether your model requires a gap between the car seat and the front seat.
If you’re unsure about the installation, certified Child Passenger Safety Technicians offer free inspections. Many fire stations, police departments, and hospitals have technicians on staff or can point you to a local inspection station. Getting this checked a few weeks before your due date saves you from scrambling.
Prepare a Safe Sleep Space
Your baby’s sleep area should be ready before delivery. The American Academy of Pediatrics recommends placing infants on their backs, alone, on a firm, flat mattress with only a fitted sheet. That means no loose blankets, pillows, stuffed animals, or bumper pads in the crib, bassinet, or portable play yard. Babies should not sleep on couches, armchairs, or in swings and car seats (outside of car travel). Room-sharing without bed-sharing is the safest setup for the first several months.
Stock Up for Postpartum Recovery
Recovery supplies are easy to overlook while you’re focused on the baby, but having them ready at home makes a real difference. For perineal soreness after a vaginal delivery, the essentials include ice packs, a peri bottle (a squirt bottle to rinse with warm water while urinating), witch hazel pads, and a cushion or padded ring to sit on. A stool softener is worth having on hand, since the first postpartum bowel movements can be uncomfortable, especially if you had tearing or an episiotomy.
For breastfeeding, keep warm and cold washcloths available. Warm compresses before feeding can help with letdown, and cold ones between feedings ease soreness. A breast pump is useful if you need to relieve engorgement or help your baby latch by expressing a small amount of milk first. A supportive bra, like a sports bra, helps whether you’re breastfeeding or not.
Stocking these items by week 36 or so gives you a buffer in case labor comes early, and means you won’t be sending someone to the store during your first days at home with a newborn.