Last updated February 2013. Planned review date: February 2014.

illustration of fetus with heading: Pregnancy calendar

First trimester - Weeks 4 to 12

The first weeks of your pregnancy are a crucial stage for your baby, as your pregnancy establishes itself.

First trimester: key stages

The first trimester starts from the first day of your last menstrual period up to the end of week 12. This means that by the time you know for sure you're pregnant, you're probably already six or more weeks along.

Feeling sick? Try...


- sparkling water
- sucking ice cubes
- small frequent meals
- travel wristbands
- foods and drinks that contain ginger (ginger biscuits, chamomile and ginger tea, ginger ale, crystallised ginger)

This trimester sees your baby grow at its fastest rate. By the end of week 12 your baby will be about the size of your little finger, all its organs will have formed and it will be practising swallowing!

The downside to all this rapid growth is that you may be feeling tired and emotional, but try not to worry; it’s just your body adjusting to the demands of pregnancy and it usually settles down by the end of this trimester.

Making changes

You may need to make some lifestyle changes. 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.

Don’t worry if you smoked or got drunk before you found out you were pregnant. Now you know that you’re pregnant, you can take steps to look after yourself and your baby. For everything you need to know on having a healthy pregnancy take a look at our section on pregnancy health.

Select any key stage from the list below to explore where you’re at now, or what the coming weeks might have in store for you. There are also plenty of helpful tips on coping with everyday pregnancy niggles such as morning sickness, cramp or indigestion.

Your pregnancy - first trimester

 

Sources

  • C Henderson, S Macdonald (2009) Myles Midwifery: A Textbook for Midwives, 15th edition, Churchill Livingstone, London
  • NICE (2010) Antenatal care: routine care for the healthy pregnant woman CG62, London, National Institute for Health and Clinical Excellence

 


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First trimester: key stages

Making changes

Your pregnancy - first trimester

Pregnancy calender



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