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13 weeks pregnant - all you need to know

Welcome to the second trimester of pregnancy, a trimester of growth where your bump will get bigger and you’ll start to feel your baby moving.

13 weeks infographic.

What does my baby look like in week 13?

Your baby is growing fast - and you may be too! You might hear their heartbeat for the first time at your antenatal appointments.

Your baby now weighs around 25g.

Although you won’t be feeling baby move just yet, they're dancing around inside you. As time goes on their jerky motions are turning into slower, more purposeful ones.

Your baby’s hands find their way to their mouth and sometimes they look like they might be yawning or breathing. At this stage your baby only sleeps for a few minutes at a time but later in pregnancy, they’ll start sleeping for longer stretches and you might even notice a pattern, or routine emerging.

Your baby’s ovaries or testes have developed inside their body and a tiny willy or penis is now forming where a bump was before.

Get weekly updates on your baby's development from our expert midwives straight to your inbox.

Your pregnancy symptoms in week 13


Not all mums-to-be have cravings. If, however, you do - that’s normal. Cravings can be triggered by hormonal changes in your body affecting taste and smell. Also, sharp dips and peaks in your blood sugar levels can leave you hankering after sugary comfort foods.

These pregnancy snacks are great healthy options to get you through the day.

Take a look at our diet and nutrition guides on food swaps for a healthy pregnancy and how to have a balanced diet in pregnancy.

Feeling constipated or bloated?

Hormones can play havoc with your digestive system in pregnancy, leaving you constipated and bloated.

Do you have a headache? Perhaps you’re uffering from cramps, indigestion, dizziness, heartburn or swollen feet?

Here’s our guide to 10 common pregnancy complaints (and how to avoid them.)

What to do in week 13

Healthy eating

Having a balanced diet in pregnancy is important for you and your baby. Good nutrition will keep you healthy and help your baby grow and develop.

If you were struggling with sickness in your first trimester and this has now stopped, you may be feeling hungrier. Although you need to eat food that is good for you and your baby, you don't need to eat for two!

You only need to increase your calorie intake in the third trimester, and then, only by 200 calories a day.

Find out more about managing your weight in pregnancy.

Can I eat packaged salad during pregnancy?

If you buy prepared salad that is pre-washed, it's fine to eat as long as you make sure you keep it in the fridge and don't eat it after the use-by date.

Check the ingredients in any packaged salads you buy to make sure they don't contain foods you should avoid in pregnancy.

Staying active will give you energy

You may have felt a bit like sleeping more over the last couple of months - but hopefully those days are over. Now’s the time to get active again. It doesn’t have to be an organized exercise class, staying active by taking the stairs or walking to work, school or the shops really helps.

Being sedentary (sitting down a lot) in pregnancy increases your risks of complications so try to avoid this.

If you were active before pregnancy you can continue doing whatever you did before at a level that feels comfortable for you. Research shows that exercise is safe and healthy in pregnancy. Here’s our guide to staying active in pregnancy.

Your pelvic floor needs to be exercised for after the birth

If you haven’t already, this is a good time to start thinking about toning up your pelvic floor muscles.

Pregnancy and giving birth put a big strain on your pelvic floor - the more you can strengthen your muscles now, the better for the birth and after. Working these muscles will also help prevent you leaking wee when you laugh, sneeze or cough. 

You could do a set of pelvic floor exercises every time you brush your teeth, wait for a bus or put the kettle on.

Have you told your manager you’re pregnant yet?

You don’t have to tell your boss that you’re pregnant until the 15th week before the week your baby is due. It may be a good idea to tell them sooner though, especially if you have a strenuous job or need lots of check-ups early in your pregnancy.

“I work for a small company and two other women had announced their pregnancies just before me so I was really worried about how my news would go down, but everyone was so supportive.”

Rachael, mum of one

Read more about working in pregnancy.


NHS Choices. You and your baby at 13–16 weeks pregnant, (Page last reviewed: 28/02/2017 Next review due: 28/02/20207)

Lennart Nilsson (2009) A Child is Born, Jonathan Cape

NICE (2008) Antenatal care for uncomplicated pregnancies,Clinical guideline [CG62] Last updated: January 2017.

RCOG (2006) Recreational Exercise and Pregnancy: Information for you, London, Royal College of Obstetricians and Gynaecologists:

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    Last reviewed on June 25th, 2018. Next review date June 25th, 2021.

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    Please note that these comments are monitored but not answered by Tommy’s. Please call your GP or maternity unit if you have concerns about your health or your baby’s health.
    • By Midwife @Tommys on 16 Apr 2018 - 16:46

      Hi Carol, So sorry to hear this. We know how difficult Hyperemesis can be. For most women this resolves at around 12-14 weeks so I really hope this is so for you and that the rest of your pregnancy goes very well. Take good car of yourself.

    • By Nikki (not verified) on 29 Mar 2018 - 02:07

      Hi I'm 13 weeks pregnant and I have had 4 miscarriages before but a son before that I'm really nervous about all this. I want to make sure everything will be ok. I been to Dr and heard baby heartbeat at 8 and 12 weeks both being 161. I want to make sure that everything is ok. Would like to hear from someone else. Oh yeah I'm a high risk cus I'm 38 years old. It's just really nerve wracking because of what I have been through before. I will be 14 weeks on the 3rd of April

    • By Midwife @Tommys on 29 Mar 2018 - 14:30

      Hi Nikki,

      Thank you for your comment. It is very understandable how you are feeling with what you have been through in the past having 4 miscarriages. From what you have said, everything sounds like this pregnancy is progressing normally, baby's heart rate is good and it sounds like your Dr is very happy with how everything is going.

      This doesn't take away the fact that you are anxious about this pregnancy and it is important that you find ways of managing this anxiety so that you can settle your nerves a little going forward in your pregnancy. Pregnancy does come with its own worries and anxieties but for some women, they do have the added stress of past experiences.

      It may be that you would benefit from some form of talking therapies like CBT, this is a great way of managing worrying thoughts and provides you with coping mechanisms to combat these worries. You can speak to your GP or midwife about getting a referral for this but the help and support is there is you ask for it. If you would like additional support then please get in touch with the Tommy's midwives on email [email protected] or call on 0800 0147 800 Monday to Friday 9am-5pm. Take Care, Tommy's Midwives x

    • By mongoose1 (not verified) on 28 Mar 2018 - 20:44

      I start a new career Tuesday 14 weeks pregnant and I have not told my boss. I feel really anxious, how do I do this as I am worried I will lose my career.

    • By Midwife @Tommys on 29 Mar 2018 - 14:01

      Hi, Thank you for your comment.

      Even if you are pregnant when you do start another job, this does not mean that you could loose your job or should be the victim of discrimination because this is against the law and your boss or employer should be well aware of your employment rights.

      If you know that you are pregnant then you do need to tell your new boss as you will be entitled to get paid when attending antenatal appointments. Your employer will also need to do a work risk assessment on you, so that you are working safely while pregnant. Please go to the following link for more information
      Please have the courage to speak to your boss, tell them how you feel and that your are really passionate about your new career. Being pregnant should not change any opportunities for you and if it does then this is discrimination. Hope this helps, if you need further information then please email the Tommy's midwives on [email protected] Take Care, Tommy's Midwives x

    • By Tshego (not verified) on 21 Mar 2018 - 07:17

      Hi I'm 13 weeks pregnant and I don't feel anything I'm worried guyz

    • By Midwife @Tommys on 21 Mar 2018 - 12:31

      Hi Tshego,
      I am unsure if you mean you do not have any pregnancy symptoms or that you have no been feeling your baby move? With regards to symptoms, some pregnant women do not have any pregnancy symptoms and this can be very normal, we are only concerned when there is a sudden loss of symptoms, then we would advise for you to be reviewed.
      At this stage in pregnancy we would not expect for you to be feeling your baby move yet, this normally happens between about 18-24 weeks of pregnancy. If you have not felt your baby move by 24 weeks then we would advise for you to speak with your midwife to be reviewed. I hope this helps, if you would like to talk further then please do email us [email protected] Best wishes, Tommy's midwife.

    • By Cheryl (not verified) on 23 Aug 2018 - 10:38

      Hallo I am 13 weeks pregnant when I sleep on my left side my legs start to pain then I stretch out and pull every thing tight in my tummy its a bad habbid but wat I want to now I did not harm baby is baby okay

    • By Midwife @Tommys on 23 Aug 2018 - 14:41

      Hi Cheryl, Thank you for your comment.
      Going to sleep on your side is a good habit to have as this is what is recommended in pregnancy and research has shown that this can reduce the risk of stillbirth. If you are having pains in your legs and then you move and it resolves then it could just be the position that you were in. This should not affect baby if you have been getting the pains in your legs but if this does continue then please contact you midwife or GP who can check you over. Take Care, Tommy's Midwives x

    • By Midwife @Tommys on 25 May 2017 - 11:52

      Thank you for your feedback about our nutrition information. We work with experts in the field and the general public to make sure all of our information is accurate and up-to-date so we will definitely consider this point when we next review our nutrition section. If you would like to be involved in the process please email my colleague Amy at [email protected] And if you have any further feedback we’d love to hear from you. Best wishes x

    • By Anonymous (not verified) on 24 May 2017 - 14:10

      The advice about low fat yoghurt being healthier than full fat is totally outdated and not scientifically-backed. You may like to think of updating it!

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