First Trimester of Pregnancy

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 foetal development in the third trimester and common third trimester symptoms. Plus, check out our comprehensive to-do list starting three months before your due date so you’re as prepared as can be.

When Does the First Trimester Start and How Long Is It?

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 37 weeks, your pregnancy is considered full term. Some mums-to-be go into labour a little earlier than this and others give birth as late as 42 weeks. Keep in mind, only around 5 percent of mums-to-be actually give birth on their due date. Most babies are born in about the week either side of their estimated due date. If you give birth before 37 weeks, it’s called a preterm or premature birth. As you enter the third trimester, it’s important to know the signs of preterm labour, just in case your little one decides to make an early appearance.

Your Baby’s Development in the Third Trimester

There’s so much going on inside as your foetus prepares to meet you. Here are just some of the foetal development milestones that happen during the third trimester:

28 Weeks: Heart to Heart

At 28 weeks, your foetus’s heartbeat will have slowed to around 110 beats per minute, from a peak of about 170 beats per minute at 9 to 10 weeks of your pregnancy. This is still much faster than your own heart rate, though, and happens because your foetus’s tiny heart can’t pump as much blood in each heartbeat, so it just works a little faster instead. By 28 weeks, the foetal heartbeat may be loud enough to be heard with just a doctor’s stethoscope and your partner may even be able to hear it by placing an ear against your belly. Keep in mind, this takes a bit of luck, as it’s difficult even for professionals to find the right spot.

30 Weeks: Shedding Hairs

During the second trimester your foetus grew a coat of fine hair, called lanugo, all over his or her body. This may start to wear off at around 30 weeks pregnant. Don’t be surprised, however, 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, although some of that vernix will also start to disappear this week.

34 Weeks: Turning Head-Down

Around the time you’re 34 weeks pregnant, or soon after, your foetus will most likely turn head down in preparation for birth. Your foetus turning head down doesn’t necessarily mean you’re about to go into labour. There’s still plenty of growing and developing to do, and the best place for that is usually in the warmth and safety of your growing bump. Keep in in mind, though, that some foetuses don’t turn head-down until just before birth, and in some rare cases it doesn’t happen at all. Your midwife or doctor can talk you through your options if your foetus is still ‘breech’ (in a feet or bottom-first position) when labour starts or as your due date nears. It some cases your doctor may recommend trying to turn your foetus manually or may recommend a caesarean section, for example.

36 Weeks: Baby Fat

As your foetus grows a layer of insulating and protecting fat under the skin, he or she is starting to look more and more like the baby you expect to see at birth. By around 36 weeks your little one will have done such a good job of growing that space will be at a premium inside your bump for these last few weeks of your pregnancy. This doesn’t mean you won’t feel regular movement, though, so let your doctor or midwife know if you notice any overall reduction in your little one’s movements. Although, your baby’s birth weight can be affected by many things like genetics and gestational age, most babies weigh somewhere between 3 and 4 kilograms at birth. In the third trimester of pregnancy, your midwife or doctor will be monitoring your foetus’s growth at your antenatal appointments by measuring your bump to estimate the size of your uterus.

37 Weeks: Full-Term Baby

At 37 weeks pregnant, your pregnancy is considered full term. This means that your little one would no longer be considered premature if you give birth at any time from now on. Of course, he or she may still spend a little more time growing and developing inside your bump so you may still have several weeks to go yet until you go into labour. In any case, by this week the lungs are formed and ready to take that first breath and the digestive system is developed and your baby would be ready for that first feed if born now.

Illustration of Foetal 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:

foetal development

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:

  • More frequent antenatal appointments. Antenatal appointments are usually scheduled for 28, 31 and 34 weeks. Then from 36 weeks, you’ll probably be offered at least one appointment every 2 weeks, and if you don’t give birth by 40 weeks, you’ll likely have at least one appointment a week thereafter.

  • Having check-ups and tests. Your doctor will let you know which specific tests and check-ups you may need during the third trimester. As an example, your doctor 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 doctor can give you the appropriate course of treatment.

  • Tracking foetal movement. If your doctor asks you to track your foetus’s movements, follow your doctor’s guidance on how to count your foetus’s kicks. Our kick count chart can also help make it easier. Your doctor can also tell you when to make contact should you think something is unusual about your foetus’s movement.

  • Upping your calories. Despite the famous saying, you don’t actually need to ‘eat for two’ – even if you’re carrying twins. Experts recommend only upping your calorie intake in the third trimester, and only by around 200 extra calories per day — that’s about two slices of wholemeal bread with some margarine. Ask your doctor for personalised advice on what a healthy pregnancy diet looks like for you based on your personal situation.

  • 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.

  • Nesting. As you approach your due date you may have a strong urge to get your home ready for your baby. This is called the ‘nesting instinct.’ Focus your energy on putting finishing touches on the nursery, washing your baby’s clothes, installing the car seat and doing some early baby proofing. Some mums-to-be also use this ‘nesting instinct’ to clean, do any niggling home repairs or cook batches of meals to freeze.

  • Watching for signs of labour. Although you could go into labour anytime, it’s most likely to happen between 39 and 41 weeks (unless you’re pregnant with twins, as multiples are often born a little earlier). This is why it’s a great idea to read up on and look out for any signs of labour now that you’re in the third trimester. Besides contractions that get progressively stronger and closer together, other early labour symptoms include your waters breaking or a ‘show’ – when the mucus plug sealing the entrance to your uterus – is ejected as a bloody or pink jelly-like discharge.

  • Finalising 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 your big naming decision. If you’re still looking, check out our Baby Name Generator. If you have a few favourite names but you’re struggling to pick, consider throwing a baby naming party — perhaps your loved ones can help you decide.

  • Don’t forget the middle names. If you’d like to give a second or third name to your little one, now is the time to start finalising your choices.

  • Rest up. During the third trimester, it’s wise to slow down and rest more often. If weather permits, take a leisurely walk outdoors a few times a week. The fresh air could perk you up and help reduce some of the stress and aches you may be feeling. Ask your partner, 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:

  • Shortness of breath. As your uterus gets larger in your abdomen and presses upwards 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 doctor or midwife right away. The good news? Once your foetus ‘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. As you enter the final weeks of your pregnancy, you may find yourself needing to pee more often. This is due to your little one shifting downwards and putting extra pressure on your bladder too. You may also find that you leak a little, especially when you laugh, sneeze, bend or lift. Wearing an absorbent sanitary pad can help soak up any of these little leaks. However, if you feel a gush or trickle of watery fluid it might be your waters breaking, so call your midwife as this is an early sign of labour. If you have a burning sensation when peeing or notice blood in your urine, see your doctor as you may have a urinary tract infection (UTI).

  • Swollen feet and ankles. Many mums-to-be notice a type of swelling, called oedema, in their ankles and feet because of extra fluid retention, hormonal changes and weight gain. It can help to wear comfortable shoes, put your feet up whenever you can and drink plenty of fluid – it may not seem logical, but drinking enough water helps flush the excess fluid out of your system. Some gradual swelling is normal during pregnancy, but a sudden swelling in the face, hands or feet could be a symptom of preeclampsia, a rare but potentially dangerous blood pressure condition that is not to be ignored. If you experience this kind of sudden swelling, especially if you also have a bad headache, problems with your vision and/or vomiting during the third trimester, seek urgent medical attention.

  • Itchy skin. As your belly grows, you may start to experience itchiness as your skin stretches and dries out. Itchy skin during pregnancy can also be the result of hormonal and chemical changes in your body. Wearing loose clothing, gently applying a moisturising lotion and cool baths can help.

  • Sore, bleeding gums. Your gums may feel sensitive, and they may swell or bleed when you brush or floss. Hormonal changes can increase the risk of plaque build-up and this is what can lead to those bleeding and inflamed gums. It might help to rinse with salt water and to use a softer brush. Keep flossing daily, brushing twice a day and going to your regular dental check-ups.

  • Braxton Hicks contractions. In the third trimester, and sometimes even earlier, you may experience Braxton Hicks or ‘false’ contractions. These ‘practice contractions’ may be uncomfortable but are usually painless. They help your muscles prepare for labour. You can usually tell Braxton Hicks contractions apart from true labour contractions by keeping in mind that Braxton Hicks come at irregular intervals and often go away if you move or change positions. True labour contractions come at regular intervals and get stronger and closer together over time.

FAQs at a Glance

  • Labour is unique for each mum¬-to-be, but the main signs that labour is approaching include:

    • Having regular contractions
    • Your water breaking
    • Noticing the mucus plug discharge.
  • Yes, it’s normal to feel more tired in the third trimester. Your body is working hard to support your growing foetus and your growing bump might be getting in the way of a good night’s sleep, too.

  • There is no official guideline in the UK on how much weight to gain during pregnancy but, on average, if you had a normal pre-pregnancy BMI you can expect to gain about 400 to 500 grams per week during the third trimester. Your doctor or midwife can give you specific, personalised information based on your situation.

  • The third trimester runs from 28 weeks until your baby is born. Your pregnancy is considered full term at 37 weeks, and most babies are born in the week either side of their due date.

  • According to experts only 5 percent of babies are born exactly on their due date. Most babies are born in the week either side of their due date.
    The due date that you get using a Due Date Calculator or from your doctor is a general estimate of when your baby will be born.

  • It’s important to keep on eating a healthy, balanced diet – with the right proportions of fruit and veg, carbohydrates, protein and dairy (or dairy substitutes) in the third trimester of pregnancy.
    If you’re suffering from heartburn as your uterus pushes up against your stomach, try eating smaller but more frequent meals.

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

  • Take a deep-dive into what’s to come in the third trimester by reading our week-by-week pregnancy articles.

  • Ask your doctor about any vaccinations you need to get this trimester, including the Tdap vaccination (which helps protect your baby against whooping cough, diphtheria and tetanus).

  • Ask your midwife or doctor how long you can safely continue working for.

  • Take a childbirth class with your partner. You’ll probably learn things like comfort measures, relaxation techniques and stretching exercises. Plus, your partner can also learn more about what to do to support you well during labour and delivery. Your doctor will be able to recommend a good class near you.

  • If you haven’t already and you’d like to have one, choose a midwife.

  • Think about whether a labour support person called a doula may be for you and start researching your options if you haven’t already.

  • 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.

  • Choose where you would like to give birth, whether it’s a hospital or birthing centre, for example. Discuss your options with your midwife and doctor, and find out whether you need to take any additional steps based on your choice.

  • If you’d like to have a birth plan, discuss your options and preferences with your doctor regarding labour and delivery.

  • Consider whether you would like to do cord blood banking, and discuss your preference with your doctor.

  • Start gathering suggestions for paediatricians.

  • Gather some recommendations for child care and babysitters so that you are ready once your baby is here.

  • If you’re having a baby shower, make sure your baby registry is ready and that the organiser of your shower has the details.

  • Purchase and install your baby car seat so it’s ready for the drive home from the hospital.

  • 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.

  • 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.

  • If you have older children, start preparing them for the arrival of their baby brother or sister.

Two Months Out

  • Keep going to all your antenatal appointments so that your doctor can follow you and your foetus’s progress as your due date nears.

  • Find out what your options are for pain management during labour 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 doctor, midwife and birth partner. If you are planning a natural delivery—in other words labour and childbirth with little or no medical intervention—find out what comfort measures and labour positions you could try as well as what facilities the hospital may have for you like a birthing ball or pool.

  • If it’s possible, tour your hospital or birth centre.

  • Plan, practice and time the route you’ll take to the hospital or birth centre. Hospitals can be very large, so it also helps to learn the way to the maternity unit once you’re there, and to find out the best entrance to use if there’s more than one.

  • 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.

  • Pack your hospital bag and have it 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.

  • Take another class—for example, try one about baby care, infant CPR or breastfeeding.

  • If you’re considered breastfeeding and would potentially like the help of a lactation consultant start researching your options now. Your midwife can also point you in the direction of additional support and resources.

  • Finish setting up and decorating your baby’s nursery.

  • Start writing thank you notes for baby shower gifts you’ve received.

  • Although you don’t need to stress about having absolutely everything in place now as you can still shop for anything you need once your baby arrives, make sure you have all the essential gear like a crib, car seat, clothes and diapers.

  • Depending on the type of work you do, you might like to start getting organised 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

  • Ask your doctor whether you will have any additional check-ups as you near your due date, and when these will be scheduled.

  • Ask your doctor, 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 centre, as some facilities may not permit recording or filming.

  • Organise a newborn photoshoot if you’d like to have one in the days after your baby’s birth.

  • Consider putting a waterproof cover on your mattress, just in case your water breaks during the night.

  • Wash everything your baby will wear and organise clothes by size so you can find what you need more easily.

  • Stock up on Pampers nappies. It’s a good idea to have a variety of nappy sizes (such as sizes NB-1 and 2) so you’re equipped for when your baby arrives, no matter what size he or she is.

  • Wipe down and sanitise anything else your baby may come in contact with like the car seat, crib and baby bottles.

  • Prepare some meals in advance and freeze them—you might not have the time or energy for cooking in the first few days and weeks after bringing your baby home.

  • 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.

  • Think about and organise who will care for your older children (and pets if you have them) during your labour and hospital stay.

  • Read up on the postpartum recovery period so that you know what kinds of things to expect in the weeks and months after your baby’s birth.

  • 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!

  • To get more information on the final weeks of pregnancy and then on baby development, sign up to receive our regular emails:

How we wrote this article
The information in this article is based on the expert advice found in trusted medical and government sources, such as the National Health Service (NHS). You can find a full list of sources used for this article below. The content on this page should not replace professional medical advice. Always consult medical professionals for full diagnosis and treatment.