Amazing Guide to your growing baby

Track the big changes you and you baby are going through each week.


Week 6

Your baby
Your baby looks a bit like a tadpole, even though she’s no bigger than a grain of rice. Her heartbeat can be picked up from an ultrasound scan. She’ll double in size this week from 4mm to 8mm.


You may feel sick or grumpy and emotional due to hormones.

  • Take folic acid until week 12.
  • Eat little and often.
  • Drink lots of fluids.
  • Start the day with bland food like toast.

Week 7

Your baby
He’s about 9mm – the size of a coffee bean. His head is emerging, and there are buds that will be his arms and legs. He has dark patches where his eyes are forming.

Your breasts may be swollen and sore. Your nausea continues and you need to wee a lot. Foods taste different.

  • See your GP if you have constant nausea.
  • Avoid undercooked meat, soft cheeses and raw eggs.

Week 8

Your baby
Your baby is prawn shaped, with a big head and tail. She is now a foetus, not an embryo, and is around 16mm long. She’s starting to move, but you won’t be able to feel it yet.

You may feel nauseous, tired and could be constipated.

  • Rest when you can.
  • Eat lots of fruit and veg, drink more fluids.
  • Avoid over-exertion.
  • Don’t take medicine unless advised.

Week 9

Your baby
He’s about 2cm long – the size of a grape. Eyelids are appearing and his sex organs are forming. An ultrasound scan will show leg movements.

You may feel irritable and weepy, and your centre of gravity is starting to change.

  • Talk to your friends or partner about your mood swings.
  • Watch your step and remove anything you could trip up on at home.

Week 10

Your baby
As your baby’s  tail shrinks, she looks more like a human. Her limbs are growing, her arms can bend and her toes and fingers lose their webbing. Her heart is fully formed. She’s about 4cm long.

You’re permanently hungry. Your uterus has grown and is pushing against your bladder. Your breasts have also grown.

  • Get measured for a maternity bra – it will feel a lot more comfy.

Week 11

Your baby
He looks like a baby but with a big head, which he can hold up and away from his chest. He has 32 tooth buds and his sucking reflex is already working. He measures about 5cm.

Your nausea should subside but the mood swings may not.

  • Your baby’s less susceptible to drugs and chemicals.
  • Drink no more than one to two units of alcohol a week.

Week 12

Your baby
An expert can tell your baby’s sex now. She is using your womb as a trampoline, but you won’t feel it. Fingers and toes have separated and hair is growing. She’s the size of a plum, about 8cm. 

Your first antenatal appointment is due and the risk of miscarriage falls. Your clothes will feel tight.

  • Take it easy.
  • See your dentist, as gums are prone to infection in pregnancy.

Week 13

Your baby
He has a recognisable chin, snub nose and large forehead. He’s sucking, swallowing and clenching his fists. By the end of this week, he’ll be almost fully formed. He’s about 9cm long.

Your tummy is growing and soon everyone will notice your bump. You may get spots due to hormonal changes.

  • Exercise moderately if you feel up to it.
  • Make sure you drink plenty of water.

Week 14

Your baby
Your baby is standing up, stretching and sitting down. An ultrasound scan may be able to detect your baby’s sex. Your baby’s still skinny, as she hasn’t developed a fat layer yet. She’s about 11cm long.

You may suffer from heartburn. Your tummy could have a dark line from your navel to your pubic hair called the linea nigra.

  • Wear loose clothing.
  • Eat little and often.

I’m 14 weeks and beginning to look like the baby you’re going to meet. I’m now starting to practise how to breathe and my tiny thumb has separated from the rest of my fingers so I can suck it.

Week 15

Your baby
He can yawn, blink, rub his eyes and suck his thumb. His nails are developing and his facial features are defined. He’s about 12.5cm and starting to gain weight.

Your heart’s pumping 20% faster to cope with the extra blood. Your hair’s thicker and you may ‘glow’. You’ll feel nauseous if you get tired and hungry.

  • Always carry a snack and drink.
  • Don’t overdo it.

Week 16

Your baby
Your baby can wave her fingers and toes about. She is covered in downy hair called lanugo (wool) to keep her warm before fat is formed. She can hear some sounds. She is 14cm long – about the length of a pencil.

You may feel the baby move – like butterflies in your stomach. It’ll be harder to sleep at night due to your growing bump.

  • Write down any worries in a notebook.

Week 17

Your baby
He has a range of expressions, from a frown to a grimace. He can bring his fingers to his thumb and his fingers all together. He’s about 16.5cm but still fits in your palm.

You may be constipated but feel as if you’re ‘leaking’ fluids, thanks to a runny nose, extra sweating and vaginal secretions.
Stay focused on eating a healthy diet.

  • Drink lots of fluids.
  • Avoid stodgy food.

Week 18

Your baby
She can punch, kick, turn and wriggle. Air sacs in her lungs and her fingerprints are developing. Her eyes may open and she’ll be aware of light. She’s 18cm. 

Babies tend to move when you’re resting, but don’t worry if you can’t feel anything yet.

  • Massage your body with wheatgerm or vitamin E oil or cream.
  • Call the NCT on 0870 444 8707 for antenatal class info.

Week 19

Your baby
Your baby is swinging around his umbilical cord. Brown-coloured fat deposits are forming, which keep him warm. He’s about 20.5cm in length.

You might suffer backache and skin pigment changes,
but you could have extra energy, too.

  • Gentle swimming is great exercise.
  • Talk your birth plan through with your midwife and birth partner, but be flexible.

I’m 19 weeks and getting bigger. I can kick, turn and leap about, though you might not feel it yet. My skin’s covered in a white substance called vernix. You may be able to tell if I’m a boy or a girl now, too.

Week 20

Your baby
Her growth rate slows. Her lungs and digestive system are maturing. She’s covered in fine hair and a waxy coating called vernix. She’s about 11oz in weight and 25cm long.

If you haven’t felt the baby move it may just mean you don’t recognise it. You may get your libido back.

  • You may feel breathless, which can signal anaemia and should be checked.

Week 21

Your baby
His nervous system, muscles and adult teeth are forming. His hearing is acute and he’ll jump at loud noises. He’s 26cm, about half as long as he’ll be when he’s born.

You may be forgetful and people will comment on your size.

  • Ignore ‘you’re so big/small’ comments. Everyone is different and bump size varies.
  • Jot dates down and make lists so you don’t forget anything.

Week 22

Your baby
Your baby is somersaulting and hiccuping – and you should be able to feel it. Her legs are now in proportion to her body. She’s 27cm long.

You’ll be piling on weight, but with the hormones settling you should be happier.

  • It’s time to buy some big knickers!
  • Read up about breastfeeding. It’s a good idea to be as informed and prepared as possible.

Week 23

Your baby
He’s now a fully-formed baby. He has a waking and sleeping pattern. He can hear his dad’s voice more easily than yours. He may be able to think. He’s about 28cm and weighs 1lb.

Your bladder is getting more squashed and you’ll need to wee more. Sleep becomes uncomfortable.

  • Sleep on your side, not your back.
  • Use a pregnancy sleep cushion.

I’m 23 weeks but I already have a sleep pattern. I like it when you move – it lulls me to sleep. But when all’s quiet, I’m raring to go! I love to hear your voice so don’t forget to say hello to me.

Week 24

Your baby
She may survive
if born now, although she’d need intensive care and help with breathing. She’s about 29cm.

You may have the occasional dizzy spell and feel faint. Your hair and nails are growing well.

  • Avoid lying on your back, as it may constrict blood flow to your heart.
  • Skin’s sensitive, so avoid hair removal creams and bleach.

Week 25

Your baby
Blood vessels continue to develop in his lungs – the last vital organ to mature. He’s about 30cm long and weighs 1lb 8oz.

Your baby’s putting pressure on your rib cage. You may have pain as your uterus stretches.

  • Avoid big meals.
  • Check out nursery equipment while you still have the energy.
  • Sit up straight to give your baby room.

Week 26

Your baby
You can see her smile and frown. Fat is forming, which will help regulate her body temperature. She’s about 30.5cm.

Your centre of gravity’s changed and you’ll need to protect your bump. Your joints are loosening up, so look after your back.

  • Avoid high heels.
  • Squat when you’re lifting something.
  • Get down on all fours daily to take the weight off your spine.

Week 27

Your baby
His transparent skin is now turning opaque. He’s practising his breathing. His eyes are fully developed. He’s about 31cm.

Congratulations, you’re in the third trimester! You’ll need lots of fluids – and a seat on the bus/train.

  • Read Prima Baby and push your stomach out on public transport so no one can ignore your bump.
  • Always carry a drink.

Week 28

Your baby
If your baby were born now, her chance of survival would be up to 95%. She measures around 32cm in length.

Your bump may itch as it swells. Some airlines won’t let you fly from this week.

  • If you go on holiday, check out where the nearest hospital is.
  • Speak to your midwife if itching is severe as it may be a sign of a harmful liver condition.

Week 29

Your baby
You should be able to feel as many as 10 kicks in a morning. His brain is gaining power and he can taste the difference between sweet and sour. He’s 34cm long.

You’ll have gained about 20lb. The extra weight puts pressure on your legs.

  • Try to put your feet up and rest. Accept help when its offered.
  • Avoid cramp by not sitting with your legs crossed.

Week 30

Your baby
The hair covering her body is starting to fall out. Her skin
is less wrinkled and she has more fat. If she hears a loud noise you’ll feel her kick. She’s 36cm. 

You may feel Braxton Hicks practice contractions.

  • Practise relaxation and breathing exercises for labour.
  • Make the most of some quality time with your partner before your baby arrives.

Week 31

Your baby
His brain and nervous system are fully developed, but his sucking reflex is still weak. He’s probably in a head-down position, though this can change. He’ll move if you prod him. He’s roughly 37cm.

You’ll feel hot and sweaty when everyone else is cold. Your tummy will be putting you off balance.

  • Watch your posture.
  • Avoid tight clothing.
  • Wear layers.

Week 32

Your baby
She’s fully formed but is still growing and gaining strength. She receives half a litre of blood a minute from the placenta. She responds to pain, light and sound. She’s about 39cm.

You’ll be feeling large and uncomfortable.

  • Change position often – if you’re sitting, stand up. If you’re on the move, lay down and rest.
  • Start doing your pelvic floor exercises.

Week 33

Your baby
Your placenta is working extra hard and is at its most efficient. At birth it will weigh about one sixth of your baby’s weight. He’s about 40cm long. 

Your navel probably sticks out and you feel you couldn’t fit another thing inside you. When you’re tired, you may have a heavy, dragging feeling in your pelvis.

  • Rest when you can.
  • Avoid lifting any heavy things.

Week 34

Your baby
She’ll move less. Her intestine is filled with meconium – a substance made up of dead cells and waste from the liver and bowel. She may pass some of this during labour. She’s 41cm.

You’ll feel breathless. Your breasts may leak yellow colostrum, which protects your baby in the first days.

  • Sit or stand up straight.
  • If your breasts begin to leak, buy pads.

Week 35

Your baby
His lungs need to mature, but his head may now be engaged. He’s 42cm and gaining ½oz a day. 

You feel huge and swollen, and could be finding it hard to get your shoes on and off. Your feet may have increased a size.

  • Wear sandals or comfy trainers.
  • Sit or lie down as often as you can, with your feet raised.
  • Eat nutritious snacks rather than big meals.

Week 36

Your baby
Her lungs are developing in preparation for breathing. If she hasn’t turned upside down, she’s probably about to. She’s roughly 44cm.

If you’ve stopped work, make sure you enjoy some relaxation time. The baby’s head may be down low in your pelvis, giving
you a few ‘shocks’.

  • Don’t sit down too quickly.
  • Contact local mum and baby groups.

Week 37

Your baby
He’s almost fully mature. He probably wouldn’t need special care if born now. His eyes are blue but can change. He’s 45cm.

Your boobs may leak, especially when you hear a baby cry. You feel so uncomfortable you’re eager to get the birth over with.

  • Get as much rest and sleep as you can.
  • If you can’t get comfortable, lie on your side with a pillow between your legs.

Week 38

Your baby
She’s full term and could be born any time. She has more than 70 reflexes. She’s around 47cm.

You feel aches and pains due to your expanded uterus. You start ‘nesting’, giving in to that incredible urge to decorate, bake and clean.

  • Don’t do anything that involves standing on a chair or ladder.
  • Pack your hospital bag and have it at the ready just in case.

Week 39

Your baby
He’s grown so rapidly he is now three times heavier than he was 11 weeks ago. He’s plumped out and measures 48cm.

You may have Braxton Hicks contractions. Your cervix will get softer and thinner.

  • You may need the loo more often, so don’t get caught short!
  • Put some meals in the freezer and stock up on essentials – you won’t have much time once the baby’s arrived.

Week 40

Your baby
Your baby’s waiting for the hormonal tip that gets things going. Only around 5% of babies arrive on their due date. The average baby weighs 7lb 7oz and is 50cm.


  • Most mums-to-be worry they won’t recognise labour signs, but you will. Remember your breathing.
  • Focus on your baby.
  • Remember, your life won’t be the same – it will be even better.

Hello Mum! You’ve waited such a long time to meet me. Now I’m here! I feel as if I know you already as your voice, heartbeat and smell are so familiar to me. I feel comforted just being near you.

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