Third Trimester Pregnancy Guide: What to Expect From Weeks 28–40
Your due date is getting closer. Here's what happens during the final trimester, from your baby's development and changing movements to prenatal appointments, signs of labor, and preparing for life after birth.
Reaching the third trimester can make everything feel a little closer. The baby clothes might be piling up, your belly is harder to ignore, and the due date that once seemed so far away is now approaching surprisingly quickly.
You may be excited to finally meet your baby. You might also be tired, uncomfortable, nervous about labor, or wondering how you're supposed to finish everything on your list before delivery.
And if this isn't your first pregnancy, you already know that having a baby doesn't automatically make the final weeks predictable. Each pregnancy can feel different.
Between weeks 28 and 40, your baby continues gaining weight, developing important organ functions, and preparing for life outside the uterus. Your body is changing, too, and prenatal appointments become increasingly focused on your health, your baby's well-being, and planning for delivery.
This guide explains what to expect in the third trimester, which symptoms are common, what happens at your prenatal visits, and what you can do to prepare without feeling as though every remaining day needs to be spent getting ready.
If you're just finishing the middle months of pregnancy, our Second Trimester Pregnancy Guide: What to Expect From Weeks 14–27 covers the changes and prenatal testing leading up to this stage.
When Does the Third Trimester Start?
The third trimester begins at 28 weeks and 0 days of pregnancy and continues until your baby is born.
An estimated due date is typically calculated around 40 weeks of pregnancy, but it isn't a guarantee of when labor will begin.
Some babies arrive earlier, some arrive on their due date, and others arrive afterward.
Not every birth between 37 and 40 weeks is classified in the same way. According to the American College of Obstetricians and Gynecologists (ACOG):
Pregnancy timing | Classification |
Before 37 weeks | Preterm |
37 weeks 0 days–38 weeks 6 days | Early term |
39 weeks 0 days–40 weeks 6 days | Full term |
41 weeks 0 days–41 weeks 6 days | Late term |
42 weeks and beyond | Postterm |
These distinctions matter because important development continues during the final weeks, even when a baby appears physically ready for birth.
If your pregnancy is uncomplicated, your healthcare professional can explain why reaching full term is beneficial and when there may be a medical reason to recommend earlier delivery.
Third Trimester Pregnancy at a Glance
Weeks | What's happening with your baby | What you may notice |
28–30 | Brain and lung development continue; movements become more noticeable | Stronger kicks, tiredness, heartburn, trouble finding a comfortable position |
31–33 | Baby continues gaining weight and developing the ability to regulate body functions | More abdominal pressure, sleep disruption, occasional practice contractions |
34–36 | Baby keeps gaining fat and preparing for birth | Pelvic pressure, changing movement sensations, more frequent appointments |
37–38 | Baby is early term and continues maturing | More noticeable pressure, cervical changes, possible early labor symptoms |
39–40 | Baby reaches full term | Labor may begin, or your provider may discuss ongoing monitoring and delivery planning |
These are general patterns, not a prediction of exactly what your pregnancy will feel like at each week.
Weeks 28–30: The Final Trimester Begins
By week 28, your baby has developed many recognizable features, but important growth is still happening.
The brain is developing rapidly, the lungs continue maturing, and your baby is becoming stronger and more coordinated.
Movements may feel more obvious now. You might notice distinct kicks, rolls, stretches, or a firm push against one side of your abdomen.
Some movements may even be visible from the outside.
Your Body at 28 Weeks
You may begin noticing more physical discomfort than you experienced during the middle of pregnancy.
Your growing uterus can place additional pressure on your bladder, stomach and surrounding muscles. Heartburn, frequent urination, lower-back discomfort, and disrupted sleep are common complaints.
You might also feel more easily winded during ordinary activities.
Although mild breathlessness can occur with pregnancy-related changes, sudden or significant breathing difficulty is not something to dismiss as normal.
If symptoms seem unusual, severe or concerning, contact your healthcare professional.
What to Discuss at Your Appointments
If it hasn't already been completed, your care team may review gestational diabetes screening, blood counts and other relevant testing.
For pregnant patients who are Rh-negative, additional blood testing and Rh immune globulin may be recommended around 28 weeks, depending on prior test results and clinical circumstances.
Your provider may also review recommended vaccinations and explain how the pattern of prenatal appointments will change during the coming weeks.
Weeks 31–33: Your Baby Is Growing, and Space Is Getting Tighter
During these weeks, your baby continues accumulating body fat and developing the systems needed to function after birth.
The brain and lungs are still maturing, and your baby's movements may feel increasingly strong.
You might feel an elbow or foot pressing outward or notice your entire abdomen changing shape as your baby stretches.
Why Do Movements Feel Different?
As your baby grows, there is less space for large movements. You may notice more rolling, stretching and pushing instead of the sharp kicks you remember from earlier weeks.
However, your baby should not simply move less because the due date is approaching.
The pattern and type of movements can change, but a noticeable reduction, stopping, or concerning change in your baby's usual movements should be reported immediately.
If you're worried about movement, contact your maternity care team rather than waiting to see whether things improve by the next day.
Are Braxton Hicks Contractions Normal?
You may notice your belly becoming temporarily tight or firm.
These practice contractions are commonly called Braxton Hicks contractions.
They are often irregular and may ease when you change position, rest, or drink fluids.
True labor contractions tend to become progressively stronger, more regular, and closer together.
If contractions are frequent, increasingly painful, or concerning before 37 weeks, contact your maternity team promptly because they could represent preterm labor.
You don't need to determine on your own whether contractions are harmless.
Weeks 34–36: Preparing for Birth Becomes More Immediate
By this stage, the final preparations may feel more urgent.
Your baby continues gaining weight, and some babies move into a head-down position in preparation for delivery.
Not every baby is head-down at the same time. Your prenatal care provider can assess fetal position and discuss any concerns.
What If Your Baby Is Breech?
A breech baby is positioned with the buttocks or feet toward the birth canal rather than the head.
Many babies change position during pregnancy, but some remain breech near delivery.
If your baby is breech around 36 weeks, your healthcare professional may discuss options such as external cephalic version, a procedure in which a clinician attempts to turn the baby from the outside under appropriate monitoring.
Whether that procedure is suitable depends on your pregnancy and medical history.
Some pregnancies require a planned cesarean delivery. Your provider should explain the benefits and risks of the available options rather than assuming one approach is right for everyone.
Group B Strep Screening
Group B Streptococcus, often called GBS, is a type of bacteria that can live naturally in the body without causing symptoms.
It is different from group A strep, the bacteria associated with strep throat.
ACOG recommends routine screening for GBS at 36 weeks 0 days through 37 weeks 6 days, with some exceptions when preventive treatment is already indicated.
The test usually involves a swab of the vagina and rectum.
If the result is positive, antibiotics are typically recommended during labor to reduce the chance of serious infection in the newborn.
A positive result does not mean you have done anything wrong or that your baby will necessarily become ill.
Vaccinations During the Third Trimester
Tdap vaccination is recommended during every pregnancy, preferably early in the 27–36-week window, to help protect newborns against pertussis.
Depending on your pregnancy timing and vaccination history, your healthcare provider may also discuss the maternal RSV vaccine.
Current U.S. guidance recommends Pfizer's Abrysvo vaccine for eligible pregnant people during weeks 32–36, using seasonal administration, typically September through January in most of the continental United States.
Maternal RSV vaccination is not repeated in subsequent pregnancies under current recommendations; the baby may instead receive a preventive RSV antibody after birth.
Most infants do not need both maternal RSV vaccination and an infant RSV antibody.
Because vaccine guidance and eligibility can change, review your specific circumstances and the current recommendations with your prenatal care team.
Weeks 37–38: Your Baby Is Early Term
Reaching 37 weeks is an important milestone, but it doesn't mean every part of development is complete.
ACOG classifies weeks 37 and 38 as early term, while weeks 39 and 40 are considered full term.
Your baby continues gaining weight and maturing during this period, especially in areas such as brain and lung development.
Will Your Baby Drop Before Labor?
Some babies move lower into the pelvis before birth, a change sometimes described as lightening.
You may notice increased pelvic pressure or a change in how you carry your belly. Breathing might feel easier, while walking or bladder pressure becomes more uncomfortable.
For some people, this happens weeks before labor. For others, it happens shortly before or during labor.
It's not a reliable countdown to delivery.
Does Losing Your Mucus Plug Mean Labor Is Starting?
The mucus plug helps seal the cervix during pregnancy.
As the cervix begins changing, you may notice thick mucus or mucus tinged with pink or brown.
This can occur before labor, but it doesn't reliably predict when your baby will arrive.
If you experience heavy bleeding, suspect your water has broken, or have other concerning symptoms, contact your maternity care team immediately.
Don't assume all bleeding near the end of pregnancy is a normal “bloody show.”
Weeks 39–40: Waiting for Labor
By 39 weeks, your pregnancy is considered full term.
You may feel physically ready to have your baby, especially if sleeping, getting dressed or moving around has become uncomfortable.
But reaching your estimated due date doesn't automatically mean labor will begin that day.
What Happens If You Reach 40 Weeks Without Labor?
Your provider may discuss continued monitoring, your cervical examination when appropriate, and whether labor induction should be considered.
The timing depends on your health, the baby's well-being, gestational age, previous pregnancy history and other medical factors.
If your pregnancy continues beyond 40 weeks, ask how your team plans to monitor the pregnancy and when they recommend discussing delivery options.
Do You Need to Try to Start Labor Yourself?
You'll probably hear plenty of suggestions from friends, relatives and social media, including spicy foods, long walks and various home remedies.
There is limited evidence that many commonly suggested methods reliably start labor.
Some methods, including certain herbal preparations or castor oil, can cause side effects and should not be used to induce labor without medical guidance.
If you're interested in ways to encourage labor or want to discuss induction, speak with your prenatal care professional.
Fetal Movement in the Third Trimester: What's Normal?
One of the most important things to understand during late pregnancy is your baby's usual movement pattern.
There is no universal number of movements that every healthy baby must make each day.
Some care teams recommend a structured kick-counting method, especially for certain medical situations, while others emphasize recognizing your baby's normal pattern.
Ask your prenatal care provider which approach they recommend.
What If Your Baby Is Moving Less?
If movement is noticeably reduced, has stopped, or feels significantly different from what is normal for your baby, contact your maternity care team immediately.
Do not wait until the next morning, drink something sweet as a substitute for assessment, or rely on an at-home Doppler.
Hearing a heartbeat at home does not reliably establish that your baby is well.
Your maternity team may recommend monitoring or an examination to evaluate the baby's condition.
Trust your concern enough to make the call.
Common Third Trimester Symptoms and Ways to Feel More Comfortable
Some third-trimester symptoms reflect the physical work of supporting a growing baby. Others can indicate a problem.
Understanding the difference can help you know when comfort measures are reasonable and when professional evaluation is needed.
Back Pain and Pelvic Pressure
As your abdomen grows, your center of gravity changes and the muscles supporting your back and pelvis work harder.
Supportive shoes, comfortable seating, gentle movement and pillows may help.
Persistent or severe pain, especially with contractions, bleeding or other symptoms, should be assessed.
Heartburn and Indigestion
Pressure on your stomach and pregnancy-related hormonal changes can worsen reflux.
Smaller meals and remaining upright after eating may help some people.
Ask your prenatal care provider which antacids or medications are appropriate if symptoms persist.
Swelling in Your Feet and Ankles
Mild swelling may occur, particularly after standing for long periods.
However, sudden or extreme swelling of the hands or face, especially with a headache or vision changes, can be a warning sign of preeclampsia.
One-sided leg swelling, redness or pain may indicate a blood clot and requires prompt medical assessment.
Difficulty Sleeping
Finding a comfortable sleeping position can become challenging.
A pillow between your knees, support under your abdomen, or a comfortable side-lying position may help.
If you wake on your back, don't panic. Reposition to a comfortable side-lying position.
Talk with your clinician about ongoing insomnia, severe sleep disruption, breathing problems, or other concerning symptoms.
Frequent Urination
As your baby grows, pressure on the bladder may increase.
Frequent urination can be common, but burning, fever, blood in the urine or other symptoms of infection deserve medical attention.
Hemorrhoids and Constipation
Hormonal changes, slower digestion and pressure from pregnancy can contribute to constipation and hemorrhoids.
Fiber-rich foods, sufficient fluids and appropriate activity can help.
If symptoms are persistent or painful, ask about pregnancy-compatible treatment rather than using medications without checking.
Fatigue
Your body is doing substantial physical work during the third trimester.
Rest when possible and consider discussing excessive fatigue with your clinician, especially if it's accompanied by dizziness, breathlessness or other symptoms.
Anemia and other medical conditions can contribute to fatigue.
Which Prenatal Appointments and Tests Happen in the Third Trimester?
Your appointments usually become more frequent as delivery approaches.
For uncomplicated pregnancies, a traditional schedule involves visits approximately every two weeks during part of the third trimester and weekly visits closer to delivery. Actual schedules vary based on your provider and medical needs.
Your care team may assess blood pressure, symptoms, fetal growth, fetal heart rate, and other factors.
They may also discuss fetal position, birth preferences and when to contact the hospital.
Approximate timing | What may happen |
Around 28 weeks | Review glucose screening, blood counts, Rh status and indicated treatments |
27–36 weeks | Tdap vaccination |
32–36 weeks, seasonally | Maternal RSV vaccination discussion when eligible |
Around 32 weeks onward | Additional fetal monitoring for certain higher-risk pregnancies |
36–37 weeks | Group B strep screening |
Late third trimester | Review fetal position, birth planning, labor instructions and delivery considerations |
Around 40 weeks and beyond | Discuss ongoing monitoring and delivery timing if pregnancy continues |
Not every patient needs additional ultrasounds, nonstress tests or other specialized surveillance.
Your provider should explain why any additional testing is recommended.
How Do You Know When Labor Is Starting?
Labor doesn't always begin in the dramatic way it's portrayed in movies.
For some people, contractions gradually become more noticeable. Others first notice leaking fluid or a clear change in pelvic pressure.
You may also experience backache or the passage of mucus from the cervix.
Braxton Hicks vs. True Labor
Braxton Hicks | True labor |
Often irregular | Contractions become more regular |
May ease with rest or changing position | Usually continue despite changing position |
May not become progressively stronger | Tend to increase in strength |
Often described as tightening | May involve increasingly painful abdominal or back contractions |
These differences can help, but they aren't a substitute for medical assessment.
If you're unsure whether you're in labor, call your maternity care team.
When Should You Go to the Hospital?
Ask your care team for personalized instructions before labor begins.
Some hospitals commonly use a contraction-timing guideline such as contractions roughly five minutes apart, lasting one minute each, for one hour. However, this isn't appropriate for everyone.
You may need earlier assessment if you've given birth before, live far from the hospital, have pregnancy complications, or have other clinical considerations.
Contact your maternity team immediately if your water breaks, you have vaginal bleeding, your baby's movements decrease, or you think labor may be starting before 37 weeks.
Severe, constant pain, heavy bleeding or other emergency symptoms require immediate medical care.
If your water breaks, tell your team when it happened, whether the fluid is clear or discolored, and whether you are having contractions.
Preparing for Labor Without Overplanning Every Detail
Birth preferences can be helpful, but they work best as a guide for discussion rather than a rigid checklist.
You might want to talk with your provider about pain management, mobility during labor, support people, induction, cesarean delivery, and immediate newborn care.
Questions Worth Asking Before Delivery
When should I call the maternity unit or come to the hospital?
What pain-relief options are available?
How does your team approach induction when it is medically recommended?
What happens if my baby is breech?
Under which circumstances might a cesarean delivery become necessary?
Can my support person remain with me?
What newborn procedures are routinely offered after birth?
How will my postpartum care and follow-up appointments be arranged?
Your questions may be different based on your medical history or previous birth experience.
If you've had a cesarean delivery before, discuss your individual options for labor or repeat cesarean delivery with your clinician rather than assuming one approach applies to everyone.
When Should You Pack Your Hospital Bag?
You don't need to pack your hospital bag months before your due date.
Many families find it practical to begin gathering items around weeks 34–36, although earlier preparation may make sense if there are pregnancy complications or a possibility of earlier delivery.
Focus on essentials for yourself, your baby and your support person.
For a practical list of what to bring and what you can leave at home, see our Pregnancy Hospital Bag Checklist.
That article covers packing in much greater detail, so you don't need to duplicate an entire checklist here.
Getting Your Home Ready for Baby
The third trimester can create an urge to finish everything: wash every outfit, assemble the nursery, organize drawers and make sure not a single baby item is missing.
But a newborn doesn't require a perfectly decorated room.
Start with the essentials that affect safety and everyday care.
A Safe Sleep Space
Prepare a crib, bassinet or other sleep product that meets current safety standards.
Use a firm, flat, noninclined sleep surface with a fitted sheet.
Keep pillows, loose blankets, stuffed animals and padded bumpers out of your baby's sleep space.
Place your baby on their back for every sleep.
A Car Seat
Choose an appropriate rear-facing car seat and make sure you understand how to install and use it before delivery.
Our Choosing a Car Seat for Your Baby: A Practical Parent's Guide explains the differences between common car-seat types and what to consider when choosing one.
Everyday Baby Essentials
A supply of diapers, wipes, appropriately sized clothing, feeding supplies and a safe place for sleep can cover many immediate needs.
You can use our Newborn Essentials Checklist to prioritize practical items without buying things simply because they appear on every registry.
Don't Forget About Postpartum Recovery
It's easy to spend the final trimester preparing for the baby while giving very little thought to the person recovering from birth.
Whether you deliver vaginally or by cesarean, your body will need time and support afterward.
Before delivery, consider how you will manage meals, household tasks, transportation, childcare for older children if applicable, and opportunities to rest.
You may also want to discuss breastfeeding support, formula feeding plans, pain relief, postpartum bleeding, mental health, and your follow-up care.
Prepare for More Than the First Few Days
Postpartum care isn't limited to the hospital stay.
ACOG recommends ongoing postpartum care rather than treating a single six-week visit as the entire recovery plan. A comprehensive postpartum visit should occur no later than 12 weeks after birth, with earlier contact and follow-up based on individual needs.
Ask your pregnancy care team when they want to see you after delivery and which symptoms need urgent evaluation.
Having help planned before birth can make the transition home less stressful.
The Emotional Side of the Third Trimester
The last weeks of pregnancy can bring excitement and a surprising amount of uncertainty.
You might feel impatient to meet your baby and worried about labor at the same time.
You may be looking forward to maternity leave, feeling concerned about childcare or finances, or wondering how life with a newborn will affect your relationships and routines.
If you're expecting another child, you may also be thinking about how an older sibling will respond.
There's no single correct emotional experience.
Talk with your care provider if anxiety, low mood, panic or distress begins interfering with sleep, daily activities or your ability to function.
Pregnancy-related mental health concerns deserve attention just as physical symptoms do.
You don't have to wait until after delivery to seek support.
Your Third Trimester Checklist
Use this as a planning guide, not a list that must be finished perfectly.
Weeks 28–32
☐ Review gestational diabetes and other prenatal test results.
☐ Discuss Tdap and any other recommended immunizations.
☐ Ask about your baby's movement pattern and when to call.
☐ Review maternity leave and benefits if relevant.
☐ Begin thinking about childbirth education, feeding preferences and postpartum support.
Weeks 33–36
☐ Confirm your delivery hospital or birth location.
☐ Discuss your baby's position and any follow-up plans.
☐ Ask about Group B strep screening.
☐ Review RSV protection options when applicable.
☐ Prepare your hospital bag.
☐ Make sure your car seat and safe sleep space are ready.
☐ Arrange childcare or household help if needed.
Weeks 37–40
☐ Review your labor instructions and emergency contacts.
☐ Confirm transportation to your delivery location.
☐ Keep an eye on your baby's usual movement pattern.
☐ Discuss any changes to your delivery plan.
☐ Ask about monitoring and next steps if pregnancy continues beyond your due date.
☐ Make room for rest and recovery rather than adding unnecessary tasks.
You may complete some of these preparations earlier or later depending on your circumstances.
When to Seek Urgent Medical Care in the Third Trimester
Pregnancy can involve uncomfortable symptoms, but certain changes should never be dismissed as normal.
The CDC identifies urgent maternal warning signs that require prompt assessment.
Seek medical care immediately for:
Severe or persistent headaches, particularly if they are worsening.
Blurred vision, flashing lights or other changes in eyesight.
Sudden or extreme swelling of the face or hands.
Chest pain, trouble breathing or fainting.
Severe or persistent abdominal pain.
Vaginal bleeding or suspected leaking amniotic fluid.
A noticeable decrease or stopping of fetal movements.
Fever of 100.4°F (38°C) or higher.
Severe nausea and vomiting.
Significant swelling, redness or pain in one leg.
Thoughts of harming yourself or your baby.
If you have an emergency or cannot reach your care team while experiencing severe symptoms, go to an emergency department or call emergency services.
Make sure medical professionals know you are pregnant.
What About Preeclampsia?
Preeclampsia is a pregnancy complication involving high blood pressure and signs of organ involvement, generally occurring after 20 weeks of pregnancy.
Possible warning signs include a severe headache, vision changes, upper abdominal pain and sudden swelling.
However, not everyone experiences obvious symptoms, which is one reason blood pressure checks and prenatal appointments are important.
If you're concerned about preeclampsia symptoms, seek medical assessment rather than waiting for your next routine visit.
Frequently Asked Questions About the Third Trimester
When does the third trimester begin?
The third trimester begins at 28 weeks of pregnancy and continues until birth.
Is 37 weeks considered full term?
No. According to ACOG, 37–38 weeks is early term, while 39–40 weeks is full term.
Should my baby move less as the due date approaches?
No. The sensations may change as your baby grows, but movement should not simply stop or become noticeably reduced. Contact your maternity care team immediately if you notice a concerning change.
What is the Group B strep test?
It is a screening swab commonly performed at 36–37 weeks to check for bacteria that can sometimes cause serious infection in newborns. If the result is positive, antibiotics are usually recommended during labor.
What do Braxton Hicks contractions feel like?
They may feel like tightening or hardening of the abdomen and often occur irregularly. True labor contractions typically become increasingly regular and stronger. Contact your care team if you're uncertain, especially before 37 weeks.
Can you still exercise in the third trimester?
Many people with uncomplicated pregnancies can continue appropriate physical activity. The type and intensity may need adjustment for comfort and safety. Ask your clinician about any pregnancy-specific restrictions.
When should I install the car seat?
Ideally, install and learn to use your baby's rear-facing car seat before delivery. Consult the car-seat manual and vehicle instructions, and consider help from a certified child passenger safety technician.
What if I don't go into labor on my due date?
Your provider can explain ongoing monitoring and whether induction should be discussed. A due date is an estimate, not a deadline.
Is it normal to feel anxious about giving birth?
Yes, many people experience some worry as delivery approaches. Persistent or overwhelming anxiety deserves support from your prenatal care team.
What should I prioritize if I haven't finished preparing for the baby?
Focus on the essentials: a safe sleep space, correctly installed car seat, basic feeding and diapering supplies, transportation plans, and support for your own recovery.
The Bottom Line
The third trimester is full of important changes, but preparing for your baby's arrival doesn't have to mean completing an endless list of tasks.
Your baby is growing and continuing to mature. Your prenatal appointments will help monitor the pregnancy, and your care team can guide you through decisions about labor, delivery and postpartum recovery.
Pay attention to your baby's usual movements, know the warning signs that need medical attention, and ask questions whenever something feels unclear.
You can prepare your home, pack your hospital bag and make plans for those first days with your newborn. But it's equally important to care for yourself and make space for support after birth.
The final weeks don't have to be perfect to be meaningful.
Medical References
A Note From Numebaby: This article provides general pregnancy education and is not a substitute for individualized prenatal care. Symptoms, testing, vaccination recommendations and delivery plans depend on your medical circumstances. Follow the guidance of your healthcare professional and seek prompt medical attention for concerning symptoms.
Comments