Third Trimester of Pregnancy: What to Expect in Weeks 28–40+

September 13, 2023

The third trimester begins at 28 weeks.

For some people, reaching this stage brings excitement and a growing sense that the baby's arrival is becoming very real. For others, it brings tiredness, physical discomfort, worries about birth — or simply a desire to get to the finish line.

Probably a mixture of all of the above.

Your baby continues to grow and develop throughout these final weeks, while your body adapts again and your antenatal care increasingly turns towards labour, birth and what happens afterwards.

Here's what to expect during the third trimester — and what is genuinely useful to prepare before your baby arrives.

What Happens During the Third Trimester?

As your pregnancy progresses, your growing uterus and the additional weight you're carrying can make everyday activities more tiring.

Common third-trimester symptoms can include:

backache
indigestion and heartburn
difficulty sleeping
leg cramps
constipation
swollen feet and ankles
feeling hot
needing to urinate frequently
pelvic pressure
Braxton Hicks contractions

Some symptoms are simply uncomfortable; others can need assessment.

For example, sudden or increasing swelling — particularly involving the face or hands — can sometimes be associated with pre-eclampsia, so don't dismiss a symptom you're worried about as “just pregnancy”. Contact your maternity team for advice.

What Are Braxton Hicks Contractions?

You may notice your bump becoming tight and then relaxing again.

These are commonly known as Braxton Hicks contractions or practice contractions. They can become more noticeable later in pregnancy and are usually painless.

If contractions become painful or start occurring regularly, contact your midwife or maternity unit because this could be a sign of labour.

If you're ever unsure whether what you're experiencing is normal, you don't have to work it out alone. Your maternity team can advise you.

Keep Paying Attention to Your Baby's Movements

Your baby's movements remain important throughout the third trimester.

There isn't a prescribed number of kicks that every baby should make each day. What matters is becoming familiar with your baby's usual pattern of movement.

You should continue to feel your baby move right up to and during labour.

Contact your midwife or maternity unit immediately if:

your baby is moving less than usual
you cannot feel your baby moving
your baby's usual pattern of movements changes

Do not wait until the following day, even if it happens during the night.

And don't use a home Doppler to reassure yourself that everything is fine. Hearing a heartbeat yourself does not reliably tell you that your baby is well.

What Antenatal Appointments Happen in the Third Trimester?

Your appointments become increasingly focused on your health, your baby's growth and movements, and preparation for birth.

At around 28 weeks, your appointment may include blood tests, blood pressure and urine checks, measuring your bump and discussing your baby's movements and emotional wellbeing.

Later appointments increasingly cover preparing for labour and birth, your birth preferences and your baby's position.

If this is your first pregnancy, you'll usually be offered additional appointments at around 31 and 40 weeks.

Your own schedule may differ depending on your circumstances and pregnancy.

Vaccinations During the Third Trimester

There are vaccinations offered during pregnancy to help protect both you and your baby.

The NHS currently recommends the RSV vaccination at around 28 weeks, although it can be given later, including up until labour. Protection produced by your immune system passes through the placenta to your baby.

The whooping cough vaccination is usually offered earlier, from around 20 weeks, and can be given from 16 to 32 weeks. If you wish to have it but haven't received it, ask your midwife or GP.

Your maternity team can advise you about the vaccinations recommended for you.

How Should You Sleep During the Third Trimester?

From 28 weeks, the safest position to go to sleep is on your side — either left or right.

Research has associated going to sleep on your back after 28 weeks with an increased risk of stillbirth.

The same applies when going to sleep at night, returning to sleep after waking and taking a daytime nap.

If you wake up on your back, don't panic. Simply turn onto your side before going back to sleep.

Preparing for Birth

The third trimester is a sensible time to start thinking more concretely about labour and birth.

That might include:

attending antenatal classes
discussing your birth preferences
learning about signs that labour has started
knowing how to contact your maternity unit
arranging transport where necessary
talking through practical plans with your partner or birth supporter
packing your hospital bag

Our What to Pack in Your Hospital Bag guide can help with the last of those.

A birth plan can be useful for recording your preferences, but remember that circumstances can change. It is a guide to what matters to you rather than a guarantee of exactly how your birth will unfold.

Preparing Your Home for Your Baby

“Nesting” is often associated with late pregnancy, and you may suddenly feel motivated to organise everything.

Or you may feel absolutely no desire to reorganise a cupboard at 36 weeks.

Both are fine.

Your baby doesn't need an Instagram-ready nursery before coming home.

Concentrate on the practical essentials first.

Creating a Safe Place for Your Baby to Sleep

This is one area where preparation really does matter.

Current NHS guidance says the safest place for a baby to sleep during the first six months is in a cot or Moses basket, on their back, in the same room as you.

The mattress should be firm, flat and waterproof.

Keep the sleeping space clear. Pillows, cot bumpers, toys and loose bedding can cover a baby's mouth or nose or contribute to overheating and should not be placed in the cot.

That's a much better preparation priority than filling a nursery with things your newborn won't need.

Car Seats and Getting Home

If your baby will travel home by car, have an appropriate infant car seat ready and familiarise yourself with fitting and using it before the birth.

Trying to decipher straps and instructions in a hospital car park while exhausted isn't an ideal first attempt.

If you're unsure whether a seat is suitable or correctly installed, seek advice from the retailer or another appropriately trained source.

What Does a Newborn Actually Need?

It's very easy to overbuy before a first baby.

In reality, newborns need relatively little to begin with: somewhere safe to sleep, appropriate clothing, nappies, feeding essentials appropriate to however you're feeding, and safe transport where required.

You can buy other things once you discover what your particular baby actually needs.

And this is where I'd make one significant change from the old article.

Don't Prepare Only for the Baby

Almost every third-trimester checklist focuses on what the baby will need.

But somebody else is about to go through birth and the early weeks afterwards: you.

Preparing for your own postpartum period can be every bit as useful as stocking nappies.

Think about:

easy meals and food for the freezer
household help
who can take care of shopping or cooking
comfortable clothes
practical feeding supplies if you intend to breastfeed
who you want visiting — and when
who you can contact if you need help
giving yourself permission to rest

Our guide So, What Does a New Mum Actually Need After Birth? looks specifically at that often-overlooked side of preparation.

If You're Planning to Breastfeed

You don't need to buy an enormous collection of breastfeeding equipment before you've even begun.

A comfortable feeding space can be useful, along with practical items such as nursing bras and breast pads if you want them.

Once your baby arrives, positioning and attachment matter far more than accumulating products.

Our Breastfeeding: Is There a Right or Wrong Way? covers latch, positioning, sore nipples and where to get breastfeeding support.

Notice that I'm not linking Silver Nipple Cups directly here. #19 already performs that job in the correct context.

Looking After Yourself in the Final Weeks

Late pregnancy can be physically and emotionally demanding.

Rest where you can. Accept help. Keep attending your antenatal appointments and continue paying attention to your baby's movements.

You also don't have to enjoy every moment.

Feeling impatient, uncomfortable, worried about birth or simply fed up with being pregnant doesn't make you ungrateful.

If anxiety or low mood is becoming difficult to manage, speak to your midwife or GP.

When Should You Contact Your Maternity Unit?

By the third trimester, make sure you know who to call and where to go if something concerns you.

Contact your maternity team urgently if, for example, your baby's movements reduce or change, you think your waters may have broken, you have vaginal bleeding or you think you may be in labour.

From around 20 weeks onwards, the appropriate service for urgent pregnancy concerns is generally your midwife or maternity unit, although arrangements can vary locally. NHS 111 can advise if you're unsure where to seek help, and 999 should be used for a life-threatening emergency.

Don't wait for your next routine appointment if you're worried about your health or your baby's health.

What Comes After the Third Trimester?

Pregnancy has three trimesters.

But the transition doesn't simply stop at birth.

The early weeks after your baby arrives are often described as the Fourth Trimester — a period of enormous physical, emotional and practical adjustment for both mother and baby.

Preparing for that period before the birth can make a great deal of sense.

Read our Fourth Trimester Guide

And for the physical side of the weeks after birth:

Read our Postpartum Recovery Guide