First trimester: weeks 1 to 12

The first weeks of your pregnancy are a vital time as your pregnancy gets established. While you get used to being pregnant, your body is busy building a baby!

Weeks 1-12 infographic

First trimester: key stages

The first trimester begins on the first day of your last period and lasts until the end of week 12. This means that by the time you know for sure you're pregnant, you might already be five or six weeks pregnant!

A lot happens during these first three months. The fertilised egg rapidly divides into layers of cells and implants in the wall of your womb where it carries on growing. These layers of cells become an embryo, which is what the baby is called at this stage.

During this trimester, your baby grows faster than at any other time. By six weeks, a heartbeat can usually be heard and by the end of week 12, your baby's bones, muscles and all the organs of the body have formed. At this point, your baby looks like a tiny human being and is now called a fetus. He or she will even be practising swallowing!

During this trimester, your baby grows faster than at any other time. By six weeks, a heartbeat can usually be heard and by the end of week 12, your baby's bones, muscles and all the organs of the body have formed. At this point, your baby looks like a tiny human being and is now called a fetus. He or she will even be practising swallowing!

Lifestyle changes in the first trimester of pregnancy

You may need to make some lifestyle changes now that you are pregnant. There are certain foods and medicines you should avoid to keep your baby safe and healthy. You’ll also need to cut out alcohol and smoking, and cut back on your caffeine intake.

Download Your guide to a healthy diet in pregnancy here.

Try not to worry if you smoked or drank alcohol before you found out you were pregnant. Now that you know, you can take steps to look after yourself and your baby.

You can also find lots of useful tips on coping with everyday pregnancy niggles such as morning sickness, cramp or indigestion.

Don't forget your mental health as well as your physical health! It's normal to feel some anxiety and stress but it shouldn't be ongoing.

Find out more about your emotions in pregnancy here

Read more about The first trimester

Read more on this topic

Sources

1. NHS Choices (2012). “Your pregnancy week by week”. National Health Services: Choices. Accessed online on 02.02.2015: http://www.nhs.uk/conditions/pregnancy-and-baby/pages/pregnancy-week-by-week.aspx#close Page last reviewed: 22/07/2014. Next review due: 22/07/2016

2. Macdonald S, Magill-Cuerden J (2012) Mayes’ Midwifery, 14th edition, London, Ballière Tindall

3. NICE (2008). “Antenatal care: NICE clinical guideline 62”. National Institue for health and care excellence 2008; accessed online on 15.01.2015: http://www.nice.org.uk/guidance/cg62/resources/guidance-antenatal-care-pdf (last review August 2014). 

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Comments

  • By Anonymous (not verified) on 5 Jul 2016 - 07:47

    Very informative and nice information indeed

  • By Anonymous (not verified) on 13 Jul 2016 - 10:45

    Wow, I'll learn a lot from this website.
    Keep it up guys.

  • By Anonymous (not verified) on 26 Jul 2016 - 02:27

    When will it be a good time to test

  • By Midwife @Tommys on 26 Jul 2016 - 15:34

    The recommended time is the day after you have missed your next period as being the most accurate time , although there are some tests on the market that state they can give an earlier result

  • By Anonymous (not verified) on 29 Jul 2016 - 16:12

    I had a positive test at home so i sent a urine sample to the doctors but it came back negative the day i got told it was negative i done another test at home and it was positive again what should i do

  • By Midwife @Tommys on 29 Jul 2016 - 16:22

    Our advice is to take any pregnancy test as a positive, tests do have slightly different sensitivity. I would suggest to wait a week and repeat the test. Or else you can go back to the GP and ask for a blood test which is more sensitive and accurate. In the meantime I would suggest to start taking folic acid and vitamin D supplement if you have not already and be aware of foods to avoid in pregnancy in case you are pregnant.

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