Third Trimester: What to Expect
Weeks 28–40: prepping for birth and baby.
By Marcus Hale · Senior gear writer & testing lead
Updated June 11, 2026
The third trimester — weeks 28 to 40 — is the final, weightiest stretch, in every sense. Your baby does the bulk of its growing and maturing now, and your body works harder to carry it. It’s a trimester of more discomfort, more frequent monitoring, and a long to-do list before the big day. This guide covers what to expect, the key appointments, and how to prepare for labor and delivery.
What’s happening with your baby
These weeks are about growth and finishing touches: your baby gains roughly half a pound a week, builds brain connections at a rapid pace, matures the lungs, and accumulates fat for temperature regulation. Most babies settle into a head-down position in preparation for birth by around 36 weeks. By 39–40 weeks your baby is full term and ready for the outside world.
What’s happening in your body
As the baby and uterus grow, expect more pronounced symptoms: back and pelvic pain, heartburn, shortness of breath, swelling in the feet and ankles, frequent urination, trouble sleeping, and Braxton Hicks contractions. Many of these are normal, but some overlap with warning signs — which is why monitoring matters. Late in the trimester, lightening (the baby dropping) may ease breathing while increasing pelvic pressure.
More frequent prenatal care
Visits ramp up: typically every two weeks from about 28 to 36 weeks, then weekly until delivery. Your provider monitors blood pressure, weight, the baby’s growth and position, and your urine for signs of preeclampsia. Around 36–37 weeks you’ll have a Group B strep test. These checkups catch issues early, so don’t skip them even if you feel fine.
Track your baby’s movements
Consistent movement is one of the best signs of well-being. Many providers recommend daily kick counts — noting how long it takes to feel about 10 movements during your baby’s active time. Get to know your baby’s normal pattern, and call your provider promptly if movement noticeably decreases. This is not something to "wait and see" on — trust the change.
Prepare for the big day
Your third-trimester checklist: finalize your birth plan and discuss it with your provider; pack your hospital bag by about 36 weeks; install and ideally have the infant car seat checked; set up the essentials at home (a safe sleep space, feeding supplies, newborn clothes and diapers); arrange help for after birth; and learn the signs of labor so you know when to go in. Preparing now prevents last-minute panic.
Know the signs of labor — and the red flags
Signs labor is approaching include lightening, increased pelvic pressure, the bloody show, and regular, intensifying contractions. Use the 5-1-1 guide (contractions five minutes apart, one minute long, for one hour) unless your provider says otherwise. Seek care immediately for your water breaking, heavy bleeding, decreased fetal movement, signs of preterm labor before 37 weeks, or symptoms of preeclampsia (severe headache, vision changes, sudden swelling).
The bottom line
The third trimester is the home stretch: your baby grows and gets into position while you manage more discomfort and more frequent visits. Pack your bag by 36 weeks, install the car seat, finalize your birth plan, do daily kick counts, and learn the signs of labor. Soon the preparation pays off — you’re almost there.
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Frequently asked questions
What happens in the third trimester?
Your baby gains significant weight, builds brain and lung maturity, and usually settles head-down in preparation for birth. You’ll likely feel more physical discomfort and have more frequent prenatal visits — every two weeks from about 28–36 weeks, then weekly until delivery — including Group B strep testing around 36–37 weeks.
How often should I feel the baby move?
Movement should stay frequent and consistent in the third trimester. Many providers suggest "kick counts" — timing how long it takes to feel 10 movements during an active period. A noticeable decrease in your baby’s usual movement warrants a prompt call to your provider, day or night.
When should I pack my hospital bag?
Have it ready by around 36 weeks, since labor can start before your due date. Include your ID and insurance, birth plan, phone and charger, going-home clothes for you and baby, and install the infant car seat in advance — it’s required to leave the hospital.
What are Braxton Hicks contractions?
Braxton Hicks are irregular, usually painless "practice" contractions that tighten and release the uterus. Unlike true labor, they don’t get longer, stronger, and closer together, and they typically ease with rest, position change, or hydration. They’re normal — but call your provider if contractions become regular and intensifying before 37 weeks.
What are the signs labor is near?
Signs include the baby "dropping" (lightening), increased pelvic pressure, loss of the mucus plug or a bloody show, loose stools, a burst of nesting energy, and regular contractions that intensify. Go in (or call) for contractions about 5 minutes apart for an hour, your water breaking, heavy bleeding, or decreased fetal movement.
References
- 1.Third Trimester — March of Dimes
- 2.How to Tell When Labor Begins — American College of Obstetricians and Gynecologists (ACOG)
