Pregnancy Timeline for the Critical First Trimester

We all hear that the first three months in a pregnancy are the critical ones.  This is when your baby is growing from a single cell to a tiny human being.  While these developments are taking place the mother needs to avoid anything that could harm her body, and therefore her baby.  This may include infections, medical or other drugs, smoking and alcohol and certain foods and herbs.  You need to get good advice about this from your doctor before you become pregnant.Although this is calculated as part of your pregnancy, the first 2 weeks you are not actually pregnant.  These are the days of your last period and the few days immediately before fertilization.By week 3, your egg has been fertilized and within hours the feverish cell division begins.  By the end of this week, the little cluster of cells have made their way from the fallopian tube to the wall of the uterus where they have attached themselves.  At this stage it is a little ball of cells with a hollow centre filled with fluid.  It is now known as an embryo.During the 4th week your clump of cells has two layers that will form into the baby’s body, with a little yolk sac that provides nourishment.  This disappears later when the placenta forms on the walls of the uterus to take over that function.   The structure is surrounded by the amnion filled with amniotic fluid to protect it.In the 5th week your embryo is forming a tiny shape with a neural tube that will become its brain and spinal cord, and a bump that is where its heart is going to develop.  The placenta that nourishes your baby is growing.By week 6, your baby’s eyes and ears are starting to form and brain and nervous system are growing.  This week your doctor may be able to pick up your baby’s first heartbeats. Little buds are forming that will grow into arms and legs.  Respiratory and digestive systems start to develop.  He is still very tiny, only a few millimetres long.During week 7, your baby is growing little paddles on the ends of the arm and leg buds where the hands and feet will be. There is now an umbilical cord that temporarily houses his intestines while he is still so tiny.In the 8th week, the fingers and toes start developing.  The joints of the arms and legs have formed and can even be flexed.  Genital buds are starting to form.During week 9, your baby has a little nose and his eyelids are forming.  His digestive system is forming and he has an anus. His or her genitals are also forming but still not distinct.  Little muscles are enabling the baby to move, but he is still so tiny you will not yet be able to feel them.The 10th week is a landmark one.  After this your baby will no longer be considered an embryo, but is now a foetus.  From now on congenital abnormalities are rare.  He is a fully formed little human being.  His fingers and toes have formed and tooth buds are growing in the gums of his mouth.  Even the testes in the male baby are functioning.This week, the 11th, your baby’s facial features are developing.  He is growing rapidly, but his head still remains the largest part of his body.  The genitals of boys and girls are starting to develop externally, but are not always easy to see.In week 12 your baby is able to swallow amniotic fluid and then pee.  His intestines are in their right place, and his vocal chords are developing.  Tiny little nails are forming on his fingers and toes.  His brain continues to develop and grow.  The first trimester is not over and to summarise the rest of your pregnancy timeline, these are the usual highlights:    In the 4th month most moms start feeling their baby’s kicking.    During the 5th month you will begin to look more obviously pregnant and your doctor will most probably be checking on your baby’s development with ultrasound.  His or her sex should be clearly discernible.    By the end of the 6th month, your baby is fully developed and stands a chance of survival if it should be born prematurely.    In the 7th month your baby can hear you and actually gets to know your voice.    During the 8th month your baby grows stronger and bigger.    After 9 months your baby is ready to be born.Welcome baby!