You’ve reached the final stretch. (Literally!) This is the most exciting and suspenseful trimester of pregnancy. You're bound to be impatient to meet your little one, but hang in there — before long you’ll have your newborn in your arms. Read on to learn about fetal development in the third trimester and common third trimester symptoms. We'll also provide a comprehensive to-do list starting three months before your baby’s arrival so that you’re as prepared as can be.
How Many Weeks Is the Third Trimester?
Officially, the third trimester runs from 28 to 40 weeks of pregnancy, lasting about 13 weeks, but in real life the third trimester ends when your baby is born.
When you reach the start of 39 weeks, your pregnancy is considered full term. Some moms-to-be go into labor a little earlier than this and others give birth as late as 42 weeks. In fact, only a small percentage of babies are born exactly on their due dates with most babies being born in the two weeks either side of their estimated due date.
Some babies are born before 37 weeks, which is called a preterm birth. As you enter the third trimester, it’s important to know the signs of preterm labor, just in case your little one decides to make an early appearance.
Read our article on full-term pregnancy for more on preterm, early term, full term, late term, and postterm births.
Your Baby’s Development in the Third Trimester
In the third trimester of pregnancy, your baby continues to grow at a fast pace — in fact, your baby will gain about half of her birth weight during the final months of your pregnancy.
By the time she's born, your baby may weigh about 6 to 9 pounds and be around 18 to 20 inches long. For more on this, read more about a baby’s average birth weight.
As your little one grows fat under her skin, she starts to look like the baby you expect to see at birth. By 36 weeks she will have done such a good job of growing that she won’t have much room to move throughout the rest of the pregnancy.
Here are a few more fetal development milestones for the third trimester:
28 Weeks: Eyes Wide Open
When you are 28 weeks pregnant, your little one can open and close his eyes, and can even sense changes in light.
30 Weeks: Shedding Hairs
During the second trimester your baby grew a coat of fine hair, called lanugo, all over his body.
Your baby may start to shed this hair sometime soon. But don’t be surprised if you notice a little leftover lanugo when your baby is born; some babies are born with patches on their shoulders, ears, and back.
Unlike lanugo, which only some babies are born with, most babies are born with some of that protective waxy coating called vernix still covering their skin.
Around this week of pregnancy, your baby may also start to grow normal hair on his head.
31 Weeks: Controlling Body Temperature
Your baby’s brain is maturing and growing rapidly this week. It can now control her body temperature, so she no longer has to rely on the temperature of your amniotic fluid for temperature control.
Practicing skin-to-skin contact after your baby is born will also help your little one regulate his body temperature.
34 Weeks: Turning Head-Down
Around the time you’re 34 weeks pregnant, or soon after, your little one will most likely turn head down in preparation for birth. She's getting ready for her big journey!
If your baby is not in a head-down position as you near the end of the third trimester — for example, if she is in a breech position — your healthcare provider may recommend trying to turn your baby or may recommend a cesarean section.
39 Weeks: Full-Term Baby
By the time you reach the start of 39 weeks, your baby is considered full term. Of course, she’ll continue to grow, and major organs like the lungs and brain will continue to develop in the years to come, but she’s ready for the outside world now.
Illustration of Fetal Development Week by Week
Click through the illustrations bellow for a visual representation of how your little one develops week to week during the third trimester:
What’s in Store for You This Trimester
Here are some of the highlights to look forward to and other things to keep in mind as you make your way through the third trimester:
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Having checkups and tests. Your healthcare provider will let you know which specific tests and checkups you may need during the third trimester. As an example, your provider will likely offer you a Group B strep test, a routine test that checks whether you carry the GBS bacteria. If the test result is positive, your provider can give you the appropriate course of treatment.
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Attending your baby shower. Take the time to enjoy this wonderful event and to bask in the love your friends and family have for you and your little one. Afterward, be sure to send thank you notes for the gifts you received and of course to the party host. If you’re still working on your baby shower gift registry, check out our ideas for what to include.
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Nesting. As you approach your due date you may have a strong urge to get your home ready for your baby. Focus your energy on putting finishing touches on your baby’s nursery, washing your baby’s clothes, installing the baby car seat, and doing some early baby proofing. Some moms-to-be may also use this “nesting instinct” to clean, do any niggling home repairs, or cook batches of meals to freeze.
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Tracking fetal movement. If your healthcare provider asks you to track your baby’s movements, follow your provider’s guidance on how to count your baby’s kicks. Ask your provider for advice on when to contact him if you think something is unusual about your baby’s movement.
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Watching for signs of labor. Although you could go into labor anytime, it’s most likely to happen between 38 and 42 weeks. Look out for any signs of labor, such as lightening (the feeling that your baby has dropped lower), loss of the mucus plug, your water breaking, or your contractions getting stronger and closer together. You can monitor your contractions with the help of a contraction tracking chart. If you’re unsure if labor has begun, call your healthcare provider.
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Reading about labor and childbirth. Whether you plan to give birth vaginally or via a cesarean section it’s a good idea to learn about all the possible eventualities. When it comes to labor, here are just some of the topics worth exploring:
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Finalizing your baby name choice. Soon enough the time will come when you’ll have your baby in your arms and you’ll have to make that final baby name decision. If you’re still looking, check out our list of 1,000 baby boy names and our list of 1,000 baby girl names. If you have a few favorite names but you’re struggling to pick, consider throwing a baby naming party — perhaps your loved ones can help you decide.
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Considering middle names. If you’d like to give a second or third name to your little one, now is the time to start finalizing your choices. Check out our articles on middle names for boys and middle names for girls for more inspiration.
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Resting. It's wise to slow down and conserve your energy for labor, childbirth, and taking care of your newborn. If weather permits, take a leisurely walk outdoors a few times a week. The fresh air will invigorate you, get your blood circulating, and help you de-stress. Ask friends or family members to help you with any last-minute errands and treat yourself to a little me-time — you deserve it!
Third Trimester Symptoms
These are some of the most common pregnancy symptoms during the third trimester:
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Shortness of breath. As your uterus gets larger, grows higher in your abdomen, and presses on your diaphragm, breathing can be difficult. You might find that you can't make it up a flight of stairs without getting winded. The best thing to do is just to take it easy, move more slowly, and stand up or sit up straight so your lungs have more room to expand. If your breathing changes dramatically, or if you have a cough or chest pain, contact your healthcare provider right away. The good news? Once your baby “drops” down into your pelvis in preparation for being born, breathing will become a little easier as the pressure is taken off your lungs.
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Frequent urination. When you enter the final weeks of your pregnancy, you may find yourself needing to pee more often. This is because as your baby moves further down into your pelvis, she may press on your bladder too. You may also find that you leak a little, especially when you laugh, sneeze, bend, or lift. If this bothers you, wear a panty liner. However, if you feel a gush or trickle of watery fluid, it could be your water breaking, a sign that labor is beginning.
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Swollen feet and ankles. Many moms-to-be notice a type of swelling, called edema, in their ankles and feet because of extra fluid retention, hormonal changes, and weight gain. If you notice this, it could help to elevate your legs whenever you can and to soak your feet in cool water. To help you feel more comfortable, you may need to buy bigger shoes.
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Itchy skin. As your belly grows, you may start to experience itchiness as your skin stretches and dries out. Gently applying a moisturizing lotion and staying well-hydrated can help.
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Sore gums and teeth feeling looser. Your gums may feel sensitive, and they may swell or bleed when you brush or floss. It might help to rinse with salt water and to use a softer brush. Hormonal changes can cause your ligaments to relax, and these same hormones may also affect the tiny ligaments that hold your teeth in place. As a result, your teeth may feel looser. Experts say that it’s unlikely you’ll actually lose a tooth for this reason, and this feeling usually goes away after you’ve given birth. Keep flossing daily, brushing twice a day, and going to your regular dental checkups.
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Braxton Hicks contractions. In the third trimester, and sometimes even earlier, you may experience false contractions, known as Braxton Hicks contractions. These “practice contractions” are useful for your body because they help your muscles prepare for labor. Braxton Hicks contractions may be mild to start with and feel like a tightening of your abdomen, but as your due date nears they can become more painful. You may be wondering how to tell the difference between Braxton Hicks and true labor contractions. Essentially, Braxton Hicks come irregularly and often go away if you move or change positions; true labor contractions get more regular over time and don’t go away.
FAQs at a Glance
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Labor is unique for each mom-to-be, but the main sign that labor is approaching is having regular contractions. You may also notice your water breaking and the mucus plug discharge.
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Yes, it’s completely normal. Many women find they are more tired in the third trimester than in the second. Your body is working hard to support your growing baby, and your bump may get in the way of a good night’s sleep, too.
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Not everyone will gain the same amount of weight during any pregnancy trimester. It all depends on your pre-pregnancy weight, your body type, your general health, and whether you're having more than one baby! In the third trimester, you might put on around 1 pound per week, for example.
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The third trimester runs from 28 weeks until your baby is born. Your pregnancy is considered full term at the start of 39 weeks, and most babies are born in the two weeks either side of their due dates.
According to experts only 1 in 20 babies are born exactly on their due dates. Most babies are born during the two weeks either side of their due dates.
The due date that you get using a Due Date Calculator or from your healthcare provider is a general estimate of when your baby will be born.
Checklist for the Third Trimester
In the third trimester, take advantage of your excitement and focus your energy on getting your pre-birth tasks done. Just remember to rest often and don’t overdo it!
Three Months Out
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Take a deep-dive into what’s to come in the third trimester by reading our week-by-week pregnancy articles.
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Ask your healthcare provider about any vaccinations you need to get this trimester, including the Tdap vaccination (which helps protect your baby against whooping cough, diphtheria, and tetanus).
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Ask your healthcare provider whether you are at a high risk of preeclampsia – a high blood pressure disorder – and what signs to look out for.
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Ask your provider how long you can safely continue working.
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Take a childbirth class with your partner. You’ll probably learn things like comfort measures, relaxation techniques, and stretching exercises. These classes will also help your partner learn about his important role. Your healthcare provider will be able to recommend a good class near you.
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Read as much as you can about labor, delivery, and baby care. This will help ease your anxieties and prepare you for the events ahead.
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Pre-register at the hospital or birth center. If you’re unsure how to do this, ask your healthcare provider.
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Purchase and install your baby car seat, so it’s ready for the drive home from the hospital and beyond.
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If you’re having a baby shower, make sure your baby registry is ready and that the organizer of your shower has the details.
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Start gathering suggestions for pediatricians and read our tips on how to find a good pediatrician.
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Stock up on household staples and supplies so that you don’t have to do any major shopping just before labor or in those first few weeks with your baby.
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If you’d like to have a birth plan, discuss your options and preferences with your healthcare provider regarding labor and delivery.
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Gather some recommendations for childcare and babysitters so that you are ready once your baby is here.
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Choose or start designing your birth announcement. Ideally, get it far enough along so that all you have left to do is fill out the date of birth and name, and add a picture.
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If you have older children, start preparing them for the arrival of their baby brother or sister.
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Consider whether you would like to do cord blood banking, and discuss your preference with your healthcare provider.
Two Months Out
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Keep going to all your prenatal appointments so that your healthcare provider can follow you and your baby’s progress as you approach your due date.
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Find out what your options are for pain management during labor and childbirth. One option as an example is to have an epidural) but there are also non-medical options as well. Discuss your preferences with your provider and birth partner. If you are planning a natural delivery —in other words labor and childbirth with little or no medical intervention — find out what comfort measures and labor positions you could try as well as what facilities the hospital may have for you like a birthing ball or pool.
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If it’s possible, tour your hospital or birth center.
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Plan, practice, and time the route you’ll take to the hospital or birth center.
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Think about who you want to be present at the birth, and discuss your birth preferences with your birth partner. Go over things like who will cut the umbilical cord.
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Have your hospital bag packed and ready to go just in case your little one makes an unexpected early appearance. Make a list of anything you can only add at the last minute (like your phone and charger) and have that on top of the bag as a reminder.
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Take another class — for example, try one about baby care, infant CPR, or breastfeeding.
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If you’re considered breastfeeding and would potentially like the help of a lactation consultant start researching your options now.
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Finish planning and decorating your baby’s nursery.
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Start writing thank you notes for baby shower gifts you’ve received.
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Check out the baby gear and baby product recommendations and reviews from Pampers Parents. You don’t need to stress about having absolutely everything in place now, though, as you can still shop for anything you need once your baby arrives. Just make sure you have all the essential gear like a crib, car seat, clothes, and diapers.
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Depending on the type of work you do, you might like to start getting organized to ensure that your co-workers know what things may need to be done while you are on maternity leave. Speak to your employer about any maternity leave paperwork that still needs to be done.
One Month Out
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Ask your healthcare provider whether you will have additional checkups as you near your due date, and when these will be scheduled.
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Ask your healthcare provider, if it’s OK to have a photographer or videographer there for the birth of your baby, if this is your preference. Then check with the hospital or birth center, as some facilities may not permit recording or filming. Organize a newborn photoshoot if you’d like to have one in the days after your baby’s birth.
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Consider putting a waterproof cover on your mattress, just in case your water breaks during the night.
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Wash everything your baby will wear and organize clothes by size so you can find what you need more easily.
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Stock up on diapers and wipes like Aqua Pure Wipes and Sensitive Wipes. It’s a good idea to have a variety of diaper sizes (such as sizes N, 1, and 2) so you’re equipped for when your baby arrives, no matter what size she is.
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Wipe down and sanitize anything else your baby may come in contact with like the car seat, crib, and baby bottles.
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Prepare some meals and stock your freezer.
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If friends or family have offered to lend a hand now or after you give birth, go ahead and take advantage of their help. Whether they’ve offered to help with minding your older children or doing grocery shopping, it can all help make this busy period a bit easier.
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Think about and organize who will care for your older children (and pets if you have them) during your labor and hospital stay.
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Read up on the postpartum recovery period so that you know what kinds of things to expect in the weeks and months after you baby’s birth.
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Sign up for on Moms Club and follow us on Instagram to get rewards for all the diapers and wipes you'll be purchasing.
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Now, there’s just one last box to check: slow down and make fewer demands on yourself. It could be a long time before you get another chance to relax like this!
