1st trimester
When we find out that we will soon have a baby, everything around us seems to change. Feelings, plans, priorities will change, but above all the biggest change during these exciting nine months is that of the baby itself who will grow little by little until you will eventually see its little face. Learn about your baby's evolution from week to week in order to live this experience to the full.
From week 0 to 4
Congratulations on getting pregnant! Once the ovule has been fertilized, the development of a new life begins. A single cell that divides and multiplies at breakneck speed: At 4 days there are already a cluster of 100 cells and... in 9 months you will have a precious baby!
The embryo grows embedded in the lining of the womb while its cells divide and grow: Some will become nervous tissue, others muscle tissue, as they begin to shape its body day by day.
Amniotic fluid protects your baby from blows and squeezing. It also maintains a stable temperature and provides a pleasant environment that allows the baby to move.
Week 5
A highly productive week begins! The embryo, which is less than 1mm in length, develops its nervous system and its blood vessels, which later will form also the umbilical cord and the heart, which will begin to beat on the 25th day of pregnancy. Also, it has already become connected to the lining of the womb via the chorionic villi and its blood circulation, although the blood will never mix with yours.
Week 6
Your baby grows at an amazing pace: it measures 4mm from his head to his feet! This is the time when the bones, the fingers, and toes begin to form, as well as the feet, ankles and wrists. The eyelids appear on the face, although they will still remain closed for some time.
Depending on the technology of your gynecologist’s ultrasound scanner, it may be possible to see the embryo or even listen to its heart for the first time. Welcome to life!
Week 7
The baby continues to grow inside the womb and will now reach a length of 8mm, almost the size of a grain of rice. The umbilical cord has been formed and together with the placenta it will constitute the connection between you and your baby during pregnancy. It will use these connections to obtain oxygen and nutrients and to get rid of waste.
Week 8
The face of the embryo begins to form, including the mouth and the tongue, as well as organs such as the heart, the digestive tract, the liver, the lungs, the kidneys, and the brain. The arms and legs also develop and they begin to move slightly. The embryo already weighs 1g and measures 13mm from head to buttocks, which is the distance known as the crown-rump length (CRL).
Week 9
With a length of almost 2cm and a weight of 2g the embryo can now be considered a fetus. Little by little the skeleton develops and acquires a more human aspect with head, body, and limbs.
Week 10
All the baby's organs are now formed and they will continue to develop, which is why towards the end of week 9 the embryo can be considered a fetus. At this stage it measures 3cm from head to buttocks, it weighs 4g and has begun floating in the amniotic fluid.
Week 11
Your baby already measures 5 centimeters! Although it is true that at this stage its size is out of proportion, as half of this length corresponds to the head. In your body the placenta begins to function optimally, which will help your fetus grow at great speed.
Week 12
With a length of 6.1cm and a weight of 14g, the fetus already possesses all of its organs and now continues to grow at a good pace, with especially the body doing most of the growing, and this corrects the great difference there was between the size of the head and that of the rest of the organism.
Week 13
Little by little your baby acquires a more human and balanced aspect: 28 grams in weight and 7.5 centimeters in length. At this stage it will put its thumb in its mouth, although it is unable to suck yet. At this stage the liver, the intestine, and the pancreas are fully-functional.
Week 14
Although you might not notice it, your baby is constantly moving about! He is learning to use his muscles and joints and by the end of the week will measure 9cm and weigh 45g.