Third Trimester

feb 11, 2022 | 3 minutes Leer

You are probably feeling as if you've reached a significant milestone by this stage. Getting to the start of your third trimester really is the beginning of the countdown to when you will be having your baby. Officially, the third trimester relates to the weeks between 28 and 40 of gestation. There can be a week or two of variation though, depending on the source.

This is the trimester when all your baby's organs and systems will be preparing for extrauterine life. Although they have been fully formed since 12 weeks, an enormous amount of growth, maturation and development has been taking place since then. Your baby's movements will become stronger, more defined, and less subtle than they have been. As your baby grows, less room will be available to move freely, so kicks and obvious changes in its position will all be clearly felt by you.

It’s time to unwrap some presents

The third trimester usually means its baby shower time. If your friends and family want to put one on for you, accept their offer in the spirit that it's made. Baby showers can be a lot of fun. It will also give you an opportunity to get together with people who you may not have time to catch up with after the baby is born.

If you don’t like being the center of attention or worry that you’ll feel awkward, aim to keep it low key. Everyone loves a baby and gets excited when one is coming. Remember, this is your chance to have a little pampering for all your hard work growing your baby.

Where’s the suitcase?

This will be the time you need to think about packing your hospital bag. Try to remember you won’t be going away for a month and be practical with what you include. Toiletries, maternity pads, pajamas and comfortable day clothes as well as diaper and clothing for the baby are some of the essentials.

If you plan to bottle feed, you’ll need to take formula, bottles, caps, and newborn nipples as well. Just be mindful that many hospitals have strict regulations around formula milk and bottles. Check with your maternity care provider if you're unsure.

At some stage, sit down with your partner and make a list of the people you will want to contact when the baby is born. Straight after birth is not the time to be searching for telephone numbers or giving your partner instructions on where at home you've written them down.

You’re having a little vacation, too

Make clear arrangements with another trusted adult regarding who will be minding your older children when you have the baby. If your partner is going to stay with you at the hospital, you may even need to make arrangements to have your pets cared for.

Apart from just being a time when the baby is finally maturing, the third trimester really is the time for organizing practicalities. Make lists, cross them off as you do things, write important dates on your calendar, and generally try to keep on track of things to stay organized.

Physical changes in the third trimester

You are certainly going to get bigger in the third trimester. Your belly is growing upwards and outwards, making deep breaths a thing of the past. You’ll possibly be feeling increasingly bulky, breathless, and swollen.

Some women carry their pregnancy neatly, as if they have popped a basketball under their sweater. Others seem to spread from their front to their back and around again. It really depends on individual shape and size and your baby's growth. There is no one way to appear.

The third trimester is when the risk of complications can peak. Pre-eclampsia, gestational diabetes, hypertension, bleeding, or problems with the amniotic fluid can all occur. This is one of the reasons why your prenatal checks will increase in frequency.

You could feel unsteady on your feet and become more prone to falling. Avoid wearing high heels and take your time getting to where you want to go.

There are emotional changes, too

You will tire more easily during your third trimester and feel the effects of nurturing your growing baby. As you get closer to term, you may feel exhausted on some days and totally fed up with being pregnant. This will undoubtedly influence your mood and how you feel generally.

You could become increasingly concerned about the labor and birth. The concept of the unknown and waiting to see how things turn out may not sit well with you, especially if you normally like to feel you are in control and have everything figured out.

You may be placing a significant emotional investment into your birth plan. Keep an open mind and try to remember that although most births proceed without complications, there is always the possibility that intervention or going off plan may become necessary.

Invest some time and energy into writing up your birth plan. Include your partner's wishes and how you feel they could best support you. If you are considering having a doula or other support people present, talk with them about how you both see their role. Remember that labor can be unpredictable and despite planning, there are often unforeseen events which can occur.

You may start to wonder how you are going to cope looking after a new baby. If you have other young children whose demands on you are high, the thought of caring for another child may seem overwhelming. Talk with your partner and organize some early support among your family and friends.

Your baby’s changes in the third trimester

As your baby progresses past 30 weeks gestation, its chances of survival upon birth are much better than in the previous weeks. For every day it remains in your uterus, its body systems are further maturing towards independent life.

When you have your prenatal checks, don’t be alarmed at your ultrasound if your baby is lying in any other position than head down. It is not uncommon for babies to prefer to lie in the breech position early in the third trimester. This may cause you some discomfort underneath your ribs. Instead of a nice round bottom nestling under your ribcage, a hard bony skull is making its presence felt.

Things to think about

Rest and put your feet up when you can. Don’t push yourself. Try to have a daytime rest every day and nurture your body.

Get the nursery ready. Wash and fold those tiny clothes and take pleasure in nesting for you little one. Take a moment, each day to just sit in your baby's room and think about how your new life will be when you have your baby. This is a lovely thing to do.

Eat when you are hungry, stop when you are full. You probably won’t feel like big, heavy meals, there's just not enough room for your stomach to hold much anymore. Remember to drink at least 64 ounces of water every day to keep you well hydrated and your mind alert. Don’t venture too far from a bathroom; it will become your new best friend in the third trimester.

Read to your baby every day if you can. Your baby will also hear music, your partner’s voice, other children's voices, and everyday domestic noises.

Third trimester weekly development

Week 28

Your baby is over 2 pounds this week. Your baby's head is in proportion to its body and it's looking more like it should. There's been lots of brain development in its sleep processes and baby is starting to have REM (Rapid Eye Movement) sleep phases from this week forward.

Week 29

Your baby has gained 10 to 14 ounces this week. This is one of the reasons why so much of its time is spent sleeping; to conserve energy and lay down its fat stores.

Week 30

Your baby's brain is maturing at a fast rate this week, so eat lots of brain food, like fish. Remember to avoid eating fish which can contain high levels of mercury.

Week 31

If you give birth now, your baby would probably be able to manage pretty well without too much intensive or special care. However, your baby’s temperature regulating ability wouldn’t be perfect, so it might need to be in an incubator which would help it to maintain an even temperature level.

Week 32

Your baby is spending a lot of time sleeping. When they are awake, you may see your belly rolling as they change its position. You may see the odd elbow or knee poke you, and you might feel it hiccupping away. There's a lot going on!

Week 33

Your baby is gaining lots of weight this week, up to almost one pound. That's a lot, considering an average weight gain for a newborn in the first few months is less than one quarter of a pound per week.

Week 34

Your baby's skin is very red and still a little loose. Your baby is blinking, moving, grabbing, and grasping. It doesn’t know it is doing these things of course; conscious thought and intent is still months away. It's also having regular cycles of rest and activity.

Week 35

Your baby is around 19 inches long this week. Your baby's brain is developing at an enormous rate. To help, eat foods high in DHA (Docosahexaenoic Acid), such as cold-water fish. Speak with your maternity care provider about taking a daily supplement of this important fatty acid.

Week 36

From this week on, your baby could engage in your pelvis, and you may feel a sense of them dropping lower. This means more breathing room for you, but more pressure on your bladder. If this is your first baby, it is not unusual for pelvic engagement not to happen until labor has already started.

Week 37

If you gave birth now, your baby’s lungs would be able to work effectively. It would be able to breathe on its own and not require support.

Week 38

From this week on, your baby is considered full-term. Their skin looks less wrinkly and has more of a visible layer of fat underneath it. The vernix, a layer which has been covering it, will start to be reabsorbed if your baby is still in the womb.

Week 39

It's all systems go from now on! Your baby is virtually ready for independent life and is preparing for birth. They are still gaining a little weight and their brain is still maturing. If you are going to have a scheduled cesarean section, this will often be the week it is planned for.

Week 40

You're there! Be ready at any moment to have your baby. It's not entirely clear what causes the onset of labor. One theory is that the baby emits a particular protein which causes the mother to start contracting.

Week 41

Every baby is on their own timeline, but you could feel short-tempered this week as you wait.

Week 42

Your baby is officially overdue. Some pregnant women will be quite relaxed about it, confident that the baby will come in its own sweet time. Others are anxious, waiting nervously for something, anything to happen.

For more information see your pregnancy week by week on

The information of this article has been reviewed by nursing experts of the Association of Women’s Health, Obstetric, & Neonatal Nurses (AWHONN). The content should not substitute medical advice from your personal healthcare provider. Please consult your healthcare provider for recommendations/diagnosis or treatment. For more advice from AWHONN nurses, visit Healthy Mom&Baby at