22/01/2014 11:17 GMT | Updated 22/05/2015 10:12 BST

T: What Is The First Trimester?

The first trimester is the term given to the first 12 weeks of pregnancy.

This is the trimester that generates the missed period, morning sickness, headaches, sore breasts, heartburn and the unusual feelings that come with early pregnancy. This is due to the massive hormonal changes your body is undergoing to accommodate the pregnancy and develop the baby.

The first trimester is also the most significant in terms of your baby's physical development. The baby will develop from a ball of cells into an almost perfectly formed, but tiny, human being - all by the 12th week of pregnancy. Additionally, the placenta is also fully developed by week 12.

As the baby's body and organs are developed in the first trimester, it is extremely important to take extra special care during this time and eat as healthily as possible, give up smoking if you are a smoker, and avoid alcohol completely. While it is best not to drink at all during pregnancy, it should be avoided completely in the first trimester.

Additionally, supplementing your diet with folic acid (vitamin B9) is recommended during the first 12 weeks. Folic acid can significantly reduce the risk of the foetus developing neural tube defects, which can lead to chronic health conditions including spina bifida.

Current advice is that a pregnant woman should take 0.4mg of folic acid every day during her first trimester.