Your pregnancy: 31 weeks pregnant

Last modified on Friday 13 May 2022

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From preparing to breastfeeding to waking up to wee in the night, here's what to expect now that you're 31 weeks pregnant and racing through your third and final trimester. Not long to go until your due date now!

What’s happening at 31 weeks?

Here are the key things you can expect from your pregnancy at this stage:

  • Your baby's growth is slowing slightly.
  • Your body is preparing for breastfeeding (whether you plan to do it or not)
  • Night-time trips to the loo may increase.
  • Your 31-week antenatal appointment is due (if this is your first baby).

How big is your baby?

Your baby is now the size of a giant Easter egg. Although your baby's growth in terms of length is starting to slow down now, they'll continue to gain more weight over the rest of the trimester.

Your baby currently weighs around 1.5kg – with the average birth weight around 3.3kg, they've got some filling out still to do! At 31 weeks, your baby is just over 41cm from head to heel.


The most important parts of your baby's development are all done! Their organs and limbs are all in place and fully-formed, they just need a little bit more time for some last-minute maturing.

Your little one's arms and legs will be pretty much in proportion to their head and body now, and you may see them move across your bump, especially when you’re in the bath. Those tiny fingers even have nails on them, which can be quite long at birth.

Your baby's bone marrow will be producing lots of lovely red blood cells, too, helping them get all the oxygen they need.

Although your baby is sensitive to light and dark, they'll have their own movement patterns right through the day and night. As always, if you notice any chances or reduction in your baby's movements, speak to your midwife straight away. Don't delay, even if it's the middle of the night.

Giant chocolate Easter egg
Your baby will be roughly the size of a giant Easter egg when you're 31 weeks pregnant.

What's going on with your body?

Are your boobs leaking yet? Not all women experience leaking breasts during pregnancy, but it's fairly common.

Ever since you were about 16 weeks pregnant, your breasts have been starting to produce colostrum; the nutrient-rich first milk for your baby.

Breastfeeding has loads of benefits for you and your baby, including:

  • Breastmilk contains antibodies that can help your baby fight infections. Many women even notice that their breastmilk changes when their baby is ill, to give them more of what they need!
  • If you breastfeed, your baby is less likely to get stomach bugs or breathing problems.
  • It reduces you risk of developing breast or ovarian cancer in later life.
  • Breastfeeding burns around 300 calories a day!
  • Once you're used to it, breastfeeding is a quick and easy way to feed your baby. No fussing with sterilisers, or having to remember to bring a bottle everywhere.

We're not going to lie though: breastfeeding can be really hard for some mums, especially in the first few weeks. Read up on what to expect now; it can help make things easier.

And if you're struggling after the birth, don't hesitate to ask your midwife or health visitor for advice, and see a breastfeeding counsellor if you need to.

Of course, it's completely up to you how you choose to feed your baby after the birth. And unfortunately, not all women are able to breastfeed, for example if you're taking medication that could affect your milk.

If you already know you're going to be giving your baby formula, check out these bottle-feeding tips.

Not only are your boobs probably leaking a bit, but you'll probably also have to wee a lot – especially during the night when the need to pee comes suddenly and frequently in your sleep. No one ever said pregnancy was glamorous!

When you go to the loo, lean forwards a little to make sure you empty your bladder fully. This can help to avoid urinary tract infections, which can be common in pregnancy.

What to expect this week: your 31 week antenatal appointment

If this is your first baby you'll have an antenatal appointment this week.

Your midwife or doctor will:

  • review, discuss and record the results of any screening tests from the last appointment
  • measure your bump with a tape measure, to monitor growth rate
  • measure your blood pressure
  • test your urine for protein

If you haven't written a birth plan yet, ask any questions during this appointment so that you can sit down and write it asap, ideally before the next appointment at 34 weeks.

And as always, if you have any concerns about your heath or your baby's health, do be sure to bring them up. There's no such thing as a silly question!

Don't forget to take along your antenatal notes and a pot of wee (if requested). Leave yourself a note the night before to remind you if pregnancy is making you forgetful.

What to do this week: practise birth positions

Although TV shows paint a picture of giving birth flat on your back in a hospital bed, in reality it can be quite different.

Once you’re in labour and contractions are underway, moving around and finding different positions can help relieve the discomfort and pain.

In fact, there's some research to suggest that staying in a more upright position during the second stage of labour – such as standing, squatting, kneeling or using a birthing seat – may help your baby to arrive more quickly, too!

Before the big day comes, it's a good idea to try out some different positions so you know what to try. If you practice them regularly throughout the rest of your pregnancy, it'll be much easier to get into position when the big day comes.

Here are some popular birth positions worth practising:

  1. Sitting back-to-front on a chair, with a cushion or pillow to rest your forearms and head on.
  2. Standing, leaning against your partner, with your arms around their neck and your head on their shoulder.
  3. Leaning forwards on to a work surface (in the delivery suite, this could be the bed) with your head down on your forearms.
  4. Kneeling on all fours on a large floor cushion or pillow, and leaning on to a birthing ball, your partner’s lap or a chair.
  5. Sitting on a birthing ball, rocking backwards and forwards
  6. Lying on your side, with your leg and arm slung over pillows or a full-body bolster
  7. Squatting supported under the arms by your partner, or with your back against a bed or sofa and your forearms on the surface. This is particularly helpful in the later stages of labour, to help encourage the pelvis to open up more fully.
  8. Rocking your pelvis backwards and forwards in any position: this will help to distract you from the pain as well as encourage your baby down the birth canal.

Your 31 week to-do list

1 Remember to keep doing your pelvic floor exercises, which can be done any time, any place. Find out why they're worth putting in the effort.

2 Make sure you go back to sleep on your side, each time you wake up or get up to pee in the night.

3 Don't overeat; you only need an extra 200 calories in this trimester, which is the equivalent of half a sandwich, a smoothie or some carrot sticks and two spoonfuls of hummus.

4 Do you have everything you need for your baby? Get the lowdown on how to find quality used baby stuff.

5 Get your partner involved in practising some different birth positions – watch the video below to get a better idea of how to do them ...

What to watch this week...

Get expert tips on what to expect at 31 weeks pregnant from our midwife.

What happens next week...

Want to know what happens when you're 32 weeks pregnant? Or maybe you've already forgotten what you read last week? Just click on the numbers above to find out more about what to expect when you're that number of weeks pregnant.

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