What To Expect During The First Trimester Of Pregnancy
Finding out that you are pregnant and expecting a baby can be a very exciting time.
While you are busy dreaming about what your child will look like, be like, and planning for all of the necessities you will require for your new bundle of joy, your body is also quite busy and going through a great deal of preparation. The first trimester of pregnancy is an extremely important time with many things going on. To give you a better idea of what to expect and what is happening, let’s take a tour of sorts inside your womb.
Even though the two week period that takes place during and immediately following your last menstrual cycle is figured into the total forty week gestation time, during these two weeks you are not really pregnant. The doctor will use the date of the first day of your last menstrual period to determine your due date; however conception actually happens roughly two weeks following the start of your menstrual cycle.
When conception takes place, the egg combines with the sperm (a process known as fertilisation) to develop a zygote, or a one celled organism. The zygote contains all the chromosomes needed to determine gender, height, hair color, eye color, and general features. Once fertilisation has happened, the zygote travels down the fallopian tube until it reaches the uterus. At this time the zygote is now referred to as a blastocyte.
Once the blastocyte makes it way to the uterus, it attaches to the uterine wall between the seventh and ninth day following conception, and the placenta starts to develop. If you have been keeping track of your monthly cycles and ovulation, chances are you have taken a pregnancy test by this point and gotten a positive result.
Baby’s First Heart Beat:
After attachment has taken place, the blastocyte officially becomes an “embryo” and the baby’s organs, spine, and brain start to form. At about the half way point of the first trimester, the baby’s circulatory system will form. When the circulatory system is complete, the heart will begin to beat resulting in the first functioning organ in your baby’s body. After this point, the doctor will be able to get a view of the heart beat during the first ultrasound.
By week six of the first trimester, your baby is roughly an eighth of an inch long, and the spine and neural tube in the brain is just about closed. The heart is beating right along, and facial features, such as the ears and mouth, start to form. The tissue that will become the ribs and the muscles are developing, as are buds which will form into legs and arms. While the baby’s skull is not firm, all of the channels and areas for spinal fluid circulation are now present.
With the eighth week, comes the development of toes and fingers, however their appearance is webbed. The baby’s joints are becoming well defined, as are the eyelids, nose, and lips.
By week nine your baby now measures about an inch in length, and the area at the bottom of the spine, referred to as the embryonic tail, is starting to disappear. The head is folded downward against the chest, and hair follicles and reproductive organs have started to form. Other important organs such as the gall bladder and the pancreas are also formed by this point.
By the end of the first trimester, your baby has shed the embryonic tail, the webbing between the toes and fingers has been lost, and all vital organs have been formed. Bones are also formed, and the brain is firing many neurons. The baby’s ears have taken shape, as well as the eyelids, and tooth buds are now developing. At this point you now have a full fledged fetus.
In the next few weeks the baby’s genitals will appear and your placenta will start cranking into high gear to prepare all the necessary nutrients for growth and development in the upcoming weeks.