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17 weeks pregnant

Welcome to week 17. You are, according to all the textbooks, in the midst of The Glory Days of Pregnancy. (If you’re still not feeling it, you have our full permission to use one of those textbooks as a missile for the next person who asks if you’re ‘blooming’ yet.) But with a bit of luck, you are well into the swing of this growing-a-baby lark now; knee-deep in nursery furniture catalogues and on the hunt for the best baby name books around.

By Mumsnet HQ | Last updated Mar 20, 2023

Your baby at 17 weeks

You could still hold your baby in the palm of your hand now but he’s getting plumper by the day and his body is starting to fill out to be more in proportion with his head. The placenta is nearly as big as he is this week and it’s working hard to give him all the nutrients he needs.

This is also a very ‘productive’ week, during which he’s creating all manner of bizarre coatings, excretions and emollients. Here are some of this week’s ‘highlights’, if you can call them that…

  • He’s putting down layers of fat and starting to fill out his wrinkly skin, which has looked a bit too big for his body until now.
  • This week he also forms a special kind of fat – rather attractively called 'brown fat' – that will insulate him when he's born. It's found at the back of his neck and around his kidneys to protect them.
  • The downside to floating in an amniotic fluid bath for nine months is gaining the distinctive look of prune. To combat this, your baby develops some protection in the form of a cheesy, white cream that covers his whole body and head, called vernix. It's made from the baby's sebaceous glands (the ones that make oily fluid to protect our skin) and acts as a waterproof layer to protect his delicate skin from becoming chapped by the amniotic fluid. It makes it easier for your baby to get through the birth canal but does make him slippery when he comes out, so the midwives will give him a quick rub down with a towel to remove it. You'll probably see a few remnants of it on your baby's skin straight after birth, though.
  • The nerves that link his muscles to his brain now have a sophisticated new addition – a special coating called myelin, which speeds up how quickly nerves and muscles are able to communicate with each other. His nerves can send electrical impulses to his muscles fast enough for him to complete quite intricate movements now. He’s not up to figure skating yet, but it’s a definite step forward.
  • And at 17 weeks he is making lots more meconium (his first bowel movement), which consists of bile salts and acids made in the liver and skin cells he has swallowed from the amniotic fluid. As if the cheesy coating and brown fat weren’t already enough of a treat!
  • To counter all the gunge this week, he’s doing some pretty clever and cute stuff, too. Inside his brain, the nerve cells are connecting to each other more and more quickly. His eyes are still shut but he can roll them from side to side and his retina can now react to light. He can also hear more and may react to sound, too, if you play loud music.
  • His heart is beating twice as fast as yours does and is being regulated by the brain already.
  • If your baby is a girl, she already has a uterus and fallopian tubes by this week.
  • The bones in his feet are starting to harden.
  • He’s pretty energetic in there, too, doing somersaults and kicking more forcefully. He will move away from any pressure on your abdominal wall now and an ultrasound probe can make him jump – a hilarious sight if you actually get to see it on the screen.

What size is the baby at 17 weeks?

He is now about 13cm from his crown to his rump, that’s roughly the size of a turnip and weighs about 140g.

Your 17-week bump

Bump size varies enormously but many women find they're starting to get something that is very much more bump than bulge by this stage. You might notice the change in your bump when you're doing things like driving the car and find your seatbelt sits slightly differently to normal. You want to get the lap part of the belt under your bump, by the way, and the diagonal part on your shoulder and between your boobs.

How is your body changing at 17 weeks pregnant?

The textbooks will all promise you’ll feel more energetic now, though some women just feel heavy and cumbersome. However, the majority of women feel less sick and tired and quite enjoy this time in the middle of the second trimester. Some even gad off for a final, child-free holiday – get them!

Your heart is pumping more blood, even faster, around your body and, to avoid your blood pressure going up, your pregnant body adapts by making your blood vessels more elastic. They can then expand to take the extra blood.

You may be more aware of your heartbeat and you can feel occasional missed beats, which is normal. But if you feel that your heart is beating irregularly you should see your doctor and get checked over.

Increased blood flow and an increase in melanin means you may notice some changes to your skin tone. You might see a dark line appear down your bump – the linea nigra – which is caused by pigmentation pooling in the area of your stomach where muscles are stretching. You may also get dark patches appearing on your hands, feet and face, known as chloasma. They all disappear again after pregnancy, so don't worry about them.

And every cloud has a silver lining – just as your waistline finally vanishes, you often find your libido returns. Pregnancy hormones can increase libido but the effect of this is often masked by suffering from pregnancy sickness and tiredness in the first trimester. Lots of women also find they just feel more confident in the buff when they have a definable ‘bump’ (as opposed to a bit of an amorphous blob around the middle).

When does a baby start kicking?

You may start feeling your baby move around this time, particularly if it isn't your first pregnancy and you therefore know what to expect. First-time mums often mistake those early flutters for wind (or that chocolate button craving they've indulged a little too enthusiastically).

17 weeks pregnant symptoms

We definitely had something to say about pregnancy symptoms in week 17… What was it? It’s on the tip of our, er… thingies… Hang on. We’ll go out of the room and come back in again. It might come back to us…

‘Preg head’

Feeling fuzzy-headed and forgetful? You’re not alone. It was long thought that 'pregnancy brain' was not a real phenomenon. However, recent research from Deakin University, published in the Medical Journal of Australia, found that there may be much more to it.

I took my son to his grandma's while I went to work. Picked up a bag I thought had his computer game in. Got to his grandma's and realised I had picked up a bag of cabbage. He was not impressed.

The study measured cognitive function in 709 pregnant women and 521 non-pregnant women and found that the pregnant ones performed less well at the tasks measuring attention, decision-making, planning and memory.

The scientists also found that the phenomenon affected the women differently at various points in pregnancy. It seemed to appear during the first trimester but the effects of pregnancy brain started to level off and disappear during the second and third trimesters.

The results contradict those of a previous study in the British Journal of Psychiatry, in which researchers tested how quickly more than 1,200 women could think and aspects of their memory. They then repeated the tests as the women became pregnant. There was no difference in the results.

So who knows? It seems obvious that you might feel more forgetful but actually you are just focusing on different areas of your life – such as which pushchair to buy rather than which strategy paper to read at work – and also have a lot more on your mind than usual, from filling in maternity leave forms, to remembering hospital appointments. But it is thought that your brain does shrink ever so slightly in pregnancy and doesn’t return to its pre-pregnant size until six months or so after birth, so we wouldn't be surprised either way.

Try to get as much sleep as you can as feeling exhausted never sharpens your memory, and keep a notebook on you to jot down anything likely to fly straight out of your head again the second after it’s occurred to you. Now… Where did we put our specs, again?

Varicose veins

With those blood vessels becoming more elastic around now you may find you suffer from varicose veins. Around 40% of pregnant women get them at some point. They look like knotty blue lumps and usually appear in the legs but occasionally you can get them in more, ahem, intimate areas, when they are known as ‘vulval varicose veins’.

There’s not much you can do to avoid them, though ensuring your weight gain is steady will help. Try to put your feet up as much as you can – they should disappear again after birth.

Wear those very attractive support socks you get in the chemist. Apparently the best thing is to put them on in the morning, before you even get out of bed. Not sure how that works with having a shower!

Things to think about during week 17 of pregnancy

This is a great time to book a last-minute holiday. At this stage of pregnancy, you should be well enough to enjoy a getaway, and not yet so big that you’re restricted to UK-only breaks due to flying regulations.

Holidaying with a bump

You don’t need to pack your entire hospital bag as hand luggage but wherever you go on holiday, take your hand-held notes with you, just in case something crops up and you need to get checked out at a local hospital.

Here are a few more things to consider when planning a holiday with a baby on board:

  • Think about choosing a destination where there are good standards of food and hygiene so you can keep within the parameters of foods you need to avoid.
  • We’re sorry to tell you this, but if you hadn’t yet said goodbye to your days of riding pillion on strange men’s scooters, eating out of street food markets and sleeping on the beach, now is not really time for a last hurrah. Save it for when the kids have left home. You’ll have more money then to enjoy it anyway.
  • Many forms of exercise and sports are great for pregnancy but don't go scuba diving as decompression sickness is too much of a risk for your baby.
  • Remember you'll get hot and tan faster than your pre-pregnant self because the amount of blood going around your body has increased and more is going to your skin and mucous membranes. You will also feel more sweaty than usual in the heat, so factor that into your choice of destination if you’re not great in hot climates generally.
  • All that extra blood going around your body can also cause you to become congested more easily. If you find your partner complaining about your snoring, maybe take an extra pillow or two away with you to prop yourself up a bit in bed. Or ask the hotel for some extras… Or tell your partner to stop moaning and get an extra room if it's that bad.
  • Think about getting a new swimming cossie or bikini, before you go. Aside from your bump getting bigger, by this stage your growing milk ducts and increased blood flow to your boobs might have given you a cleavage you could drown a mouse in, so you might want to treat yourself to something bigger and a little more supportive.

What Mumsnetters say

"I've felt a few movements here and there and am feeling crazy in love want my baby! I want my 20-week scan now! I want to know what sex bean I'm growing. Anyone else felt this sudden surge of love or is it just me?"

"I have been having a lot of wind the past two weeks but the movement last night was very different to what I have been experiencing. I didn't fart so assume it was the baby!"

"17 weeks is bang in the middle of the golden window between first trimester hell and being a big heffalump!"

What's next: 18 weeks pregnant