FIRST DAY OF YOUR LAST PERIOD

The First Trimester

This trimester is classed as the first day of your last period, through to the end of week 12. More often than not, you’ll already be in week 4 -6, halfway through your first trimester before you actually find out you are pregnant! You also may not show any symptoms until around the 5^th or 6^th week.

The first trimester is when your baby will grow at the fastest rate. Here are some key developments your baby will go through in the first 12 weeks.

   

Week 5 – Your baby will be around 3 – 5mm in size, about the size of an apple pip. Even at this small size, this is when the brain, spine and nervous system begin development. The embryo’s needs are still being met by the foetuses sac. 

Week 6 – Your baby will be around the size of a pea. The heart is developing quickly, growing from a tiny tube into the complex chambers which will pump the blood through its body. Even at this early stage, a heartbeat can sometimes be detected on an ultrasound. 

Week 7 – Your baby’s limbs will start to develop. Its eyes are now visible on an ultrasound and the tiny jaw has now formed. 

Week 8 – Your baby is now about 2cm long. Its heart is beating at around 160 beats per minute. Your baby will now have tiny fingers and toes and will have skin. It’s around this time that your baby will start moving around, but you won’t be able to feel this sensation until a little later on in your pregnancy. 
               
               
           
       

Week 9 – Your baby’s facial features are becoming more distinctive. Its fingers and toes are growing longer. It’s in this week that the baby’s digestive system and muscular diaphragm are developing, which allows your baby to breathe
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Week 10 – The placenta is still developing at this point, but it is now able to provide your baby with its needs. The skull is starting to change from cartilage to bone, but is still soft and flexible enough to allow your baby’s brain to grow. Your baby now starts to look like a baby. 

  The Fit And Healthy Pregnancy Guide 

Week 11 – Your baby’s fingers and toes are now fully developed and the webbing between the digits has gone. Your baby will now be able to kick and stretch, the neck has lengthened and it will be able to move freely within the amniotic sac. Your baby’s ears are now in position and its facial features can now be seen on an ultrasound scan.

Week 12 – The final week of your first trimester. At 12 weeks you usually have your first ultrasound scan. You baby is now around 6cm in length. Your baby’s heart is beating twice as fast as your own to pump the blood around its body. Its arms and legs are fully lengthened and fully formed, allowing it to bend its wrists and elbows. Your baby will be moving around a lot now!  Although sex is determined at conception, it is in this week that the baby’s sex organs start to develop. It is still too early to determine sex on an ultrasound though.

Your baby is growing fast, and the changes in your hormones will start to cause changes to your body. Because your baby is growing at such a fast rate, it is normally in the first trimester when you will feel most tired, run down and may feel faint. 

One of the most important points to remember at this stage is that you get enough rest. Try to get sound sleep and get balanced pregnancy diet.