Your pregnancy: 21 weeks pregnant

Last modified on Thursday 12 May 2022

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Over halfway through your pregnancy, it's time to enjoy the energy you (hopefully) have and start firming up where and how you want your labour and birth to be. Here's what to expect now that you're 21 weeks pregnant and well into your second trimester.

What's happening at 21 weeks?

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

  • Your baby may remember sounds they hear from now on.
  • You might find it tricky to get a good night's sleep.
  • Time to start thinking about a labour and birth plan, if you haven't already.
  • Varicose veins may start appearing – time to put your feet up as much as you can!

How big is your baby?

This week your baby is around the size of a tub of Häagen-Dazs ice cream. Now measured from crown to heel, your little one is about 26.7cm long and weighs around 360g.

Your baby's finer features are starting to thicken out too, like the eyebrows and lips, which are becoming more pronounced. Babies even grow fine hair all over them (lanugo), so your baby may be sporting a moustache as we speak!


Your baby is also starting to develop the nerves that will control the senses, enabling the sensations of touch, smell, hearing, sight and taste.

As well as all all of this, your baby has already started to develop a primitive memory. Try playing music to your bump each day. Research says that babies will be able to recognise music they hear in the womb, after they've been born.

Tub of Häagen-Dazs ice cream
Your baby will be around the size of a tub of Häagen-Dazs ice cream when you're 21 weeks pregnant.

What's going on with your body?

This stage of your pregnancy usually means you're about the most comfortable and energetic that you're going to be, during the daytime.

However, the combination of restlessness, crazy dreams and a growing bump can mean that getting a good night's sleep is easier said than done.

Woken up by snoring? Before you blame your other half, it might be you. Yes, another thing to interrupt your sleep. It’s caused by your nasal passages swelling a little.

Try using a pillow or pregnancy support cushion to nestle your bump, and remember to get used to going to sleep on your side, as later in pregnancy, this will help to prevent stillbirth. It was once recommended that you lie on your left, but according to latest research it doesn't matter what side you lie on – just so long as it's not your back.

Try not to worry too much if you roll over in the night; the most important thing is to start off by going to sleep on your side.

If you do want to be extra careful, though, many women swear by wearing a T-shirt with a chest pocket back-to-front at night; simply pop something in the pocket that will wake you up when you roll over onto it. This should help you learn to stay on your side.

What to expect this week: varicose veins

You may have noticed some varicose veins appearing by now. Not all expectant mums get them – although around 40% do – and a lot is to do with genetics so ask your mum if she got them.

At their worst, they can look like fat, knotty blood vessels visible below the skin and can be pretty unsightly. In less severe cases, they’re achy, slightly swollen veins that don’t cause too much trouble.

Varicose veins are caused by an increased amount of progesterone in the system that makes the blood vessels relax. This means that the valves are less able to stop the back-flow of blood. When this happens, blood pools in the veins, causing them to appear varicose.

Other causes include the general increased volume of blood in pregnancy, which puts the blood vessels under greater strain, and the increasing weight of your uterus on a major vein called the inferior vena cava, which puts extra pressure on the legs.

Help keep them to a minimum by putting your feet up whenever you can and don't cross your legs when you're sitting down. Wearing support tights can help with circulation, too.

Varicose veins can also appear 'down there', too (known as vulvar varicose veins). This can be very uncomfortable, especially if they are around your knicker line.

This shouldn’t interfere in any way with the birth, and should go back to normal afterwards. If you do suffer from this tricky problem, ask your midwife for advice. She'll have seen and heard about it before.

What to do this week: think about your labour and birth options

Home or hospital? Active birth or water birth? What kind of pain relief do you want?

There's so much choice that deciding where and how to give birth can be a daunting thought. Now’s a good time to start thinking about your options.

It's a good idea to write a 'birth plan' that covers all your wishes for the labour and birth. Follow our birth plan template to give you a sense of what to include.

Have a chat with your midwife about any concerns or questions you might have. And remember that even with the best laid plans, things can pan out differently on the day, so try and be as open minded as you can.

For example, if your baby is in extreme distress, a c-section could end up being the safest thing for you both. So try to think not only about what you would like to happen if everything goes well, but also what you would prefer in different circumstances. For example, if labour isn't progressing well, would you rather be induced or wait it out?

Find out about your choices for where to have your baby below and read reviews and information about your local hospitals and birth centres.

Some maternity units offer private side rooms you can pay for but don't bank on getting one, even if you want one. They fill up fast and actually, with a straightforward labour these days you'll probably be home within 24 hours or less.

If your pregnancy is considered low risk, you can also choose to give birth at a Community Birthing Centre, also known as a midwife-led unit (MLU). These centres are run by midwives instead of doctors and offer more home comforts than a hospital. However, you can't have an epidural as there won't be an anaesthetist available. Other pain relief methods are on offer, such as gas and air (Entonox).

Some birth centres are attached to hospitals – enabling a quick transfer if your baby is in distress or you need more pain relief – while others are separate, and may require an ambulance transfer if there are any problems.

Find hospitals and birth centres in your area.

Every mother is also entitled to request a home birth. Some women feel more at ease in the comfort of their own home and this can be beneficial to labour.

Amazingly, studies suggest that, if you've had a baby before and your pregnancy is low risk, it's just as safe for you to have your baby at home as it is at a hospital or birth centre. So it's definitely one to consider.

However, midwife provision for home births varies greatly throughout the country. In particular, during the pandemic, home birth may be less available than usual. Check with your midwife to find out what's available locally.

Find out more about home births here.

If it's more support you're after, then you might want to look into using a Doula. Doulas are experienced women who can offer support to women before, during and after labour and birth. Their support is emotional and practical but not medical.

Find out more about Doulas here.

Your 21 week to-do list

1 Sleep on your side – this is recommended from your third trimester but there's no harm in getting used to doing it earlier. Remember, it doesn't matter if you wake up on your back, just move back on to your side when you can.

2 Start thinking about your birth plan. Use our birth plan template to get started.

3 If you know the sex of your baby start narrowing down names. To help, here are the top 100 boys' names. And here are the top 100 girls' names.

4 Book a tour at your chosen delivery ward or birth centre. Not all of them do them these days but it can be handy to know what to expect and where you'll need to go when you're in labour.

5 If you haven't yet, now's the time to tell your employer you're pregnant. You need to do this by 15 weeks before your due date, which is usually around 25 weeks (but may be earlier, for example if you're expecting twins or more).

What to watch this week...

Get expert tips on what to expect at 21 weeks pregnant from our midwife.

What happens next week...

Want to know what happens when you're 22 weeks pregnant? Or do you need to remind yourself 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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