Third Trimester of Pregnancy: 28-40 Weeks
You've reached the final stretch. (Literally!) This is the most exciting and suspenseful trimester of pregnancy — the climax of which is taking your sweet baby home. Take your time planning for the birth and what comes afterward, and enjoy these last few weeks of pregnancy.
How Many Weeks Is the Third Trimester?
The third trimester runs from 28 to 40 weeks of pregnancy, so lasting about 13 weeks. By the time you reach 39 weeks, your pregnancy is considered full term. Keep in mind that some moms-to-be go into labour earlier and others give birth as late as 42 weeks, so the exact length of this trimester for you will depend on when your baby is born.
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 pregnancy. By the time she's born, she may weigh about 6 to 9 pounds (2700 to 4000 grams) and be around 18 to 20 inches (45 to 50 centimetres) long. 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 development milestones to watch for during this 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. 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.
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!
39 Weeks: Full-Term Baby
By the time you reach 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.
What's Going On in the Third Trimester
Keep in mind that you could go into labour anytime, but most likely between 38 and 42 weeks. Look out for any signs of labour, such as your water breaking or your contractions getting stronger and closer together. You can read up on comfort measures during labour and even take our labour pain management quiz. Your healthcare provider will be able to tell you when it's time to go to the hospital or birthing centre.
In the third trimester, it's a good idea to have your hospital bag packed and ready to go, just in case your little one makes an unexpected early appearance.
It's also wise to slow down and rest more often. 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 reduce some of the stress and aches you may be feeling. 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
You might experience a variety of pregnancy symptoms in the third trimester, such as leg cramps, heartburn, varicose veins, backaches, fatigue, hemorrhoids, numbness in the legs and feet, and itchy skin. Because some of the most common pregnancy symptoms during this trimester include breathlessness, frequent urination, swollen feet, and Braxton Hicks contractions, we'll take a look at these in a little more detail now:
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.
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, in which case contact your healthcare provider as this is a sign that labour is beginning.
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.
Braxton Hicks contractions. In the third trimester, and sometimes even earlier, you may experience false contractions. These “practice contractions” are useful for your body because they help your muscles prepare for labour. Braxton Hicks contractions may start out quite mild 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 labour contractions. Essentially, Braxton Hicks come irregularly and often go away if you move or change positions; true labour contractions get more regular over time and don't go away.
Third Trimester To-Do's
In the third trimester, take advantage of your excitement and focus your energy on getting your pre-birth tasks done. Though remember to rest often, and don't overdo it! Use this checklist to help you get things sorted before your baby arrives.
Three Months Out
Take a childbirth class with your partner. You'll probably learn things like comfort measures, relaxation techniques, and stretching exercises that may help you through the third trimester of your pregnancy. These classes will also help your partner learn about his or her important role. Your healthcare provider will be able to recommend a good class near you.
Read as much as you can about labour, delivery, and baby care. This will help ease your anxieties and prepare you for the events ahead.
Purchase and install your baby car seat, so it's ready for the drive home from the hospital and beyond.
If you're having a baby shower, make sure your baby registry is ready and that the organizer of your shower has the details.
Start gathering suggestions for pediatricians and read our tips on how to find a good pediatrician.
Stock up on household staples and supplies so that you don't have to do any major shopping just before labour or in those first few weeks with your baby.
Pre-register at the hospital or birth centre. If you're unsure how, ask your healthcare provider.
If you'd like to have a birth plan, discuss your options and preferences with your healthcare provider regarding labour and delivery.
Gather some options for childcare and babysitters so that you are ready once your baby is here.
Help your baby shower host with any final preparations or follow-ups.
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.
Two Months Out
Take another class — for example, try one about baby care, infant CPR, or breastfeeding.
Finish planning and decorating your baby's nursery.
Stock up on diapers and wipes like Pampers Swaddlers and Complete Clean 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.
Think about who you want to be there at the birth and who could help after your baby is born.
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.
If it's possible, tour your hospital or birth centre.
Plan, practise, and time the route you'll take to the hospital or birth centre.
Start writing thank you notes for baby shower gifts you've received.
One Month Out
Wash everything your baby will wear.
Prepare some meals and stock your freezer.
Download the Pampers Rewards app, if you haven't already, so you get rewards for all the diapers and wipes you'll be using.
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!
FAQs at a Glance
What are the signs of labour approaching? Labour is unique for each mom¬-to-be, but the main sign that labour is approaching is having regular contractions. You may also experience your water breaking and the mucus plug discharge. Read more about some early signs of labour.
Is it normal to be really tired in the third trimester? 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.
How much weight do you gain in the third trimester? 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 0.8 to 1 pound per week, for example, or between 0.36 and 0.45 kilograms.
Checklist for This Trimester
Sign up for and attend childbirth classes to help you get ready for the big day
Prepare a birth plan, if you want one.
Choose a pediatrician.
Get prepared for your little one’s arrival by stocking up on baby gear like diapers and wipes, clothes, and nursery essentials.
Download our pregnancy guide for more information on what’s to come in the final weeks of your pregnancy.
Sign up for even more pregnancy tips here: