Congratulations! You are 9 months away from what is probably the biggest day of your life. Hence, the next few months are going to be vital for you. Your baby at the beginning of its long and exciting journey is about the size of a rice grain. For those who did not know, let us offer an interesting trivia about the first trimester of pregnancy. A majority of women are not actually pregnant during what is usually considered the first week or two of the first trimester. Conception begins two weeks after you get your periods. In calculating the forty-week period allotted for pregnancy to reach full term, doctors include the date from which your last period began. Hence, contrary to popular belief, periods actually form an integral part of the overall pregnancy term. According to medical science, you are pregnant even before there is so much as not a hint of pregnancy in you! Keeping such considerations in mind, here is a sneak peek into the changes likely to take place inside you body during the first trimester.
Stages of development
Stage 1: One to four weeks
Stage 2: Five to eight weeks
Stage 3: Nine to twelve weeks
First month
As discussed already, the first month is considered to begin right after the first day of the menstrual period. The egg and sperm meet in the Fallopian tube to trigger fertilization. A single sperm penetrates the egg cell of the mother and gives birth forms a third cell known as zygote. The zygote is what a few months down the line develops into a full grown baby. Divisions occur rapidly within the fertilized egg as it leaves the Fallopian tube and travels towards the uterus. At three weeks, the developing embryo starts looking for a nice place in the uterus to implant. As soon as it finds one, the zygote immediately takes shelter beneath the uterus’s surface. From this stage onward, the zygote will come to be known as a blastocyst.
The developing embryo rapidly acquires the ability to reproduce on its own: a process through which identical twins are born. As the fourth week takes off, you stop getting your periods. The changes taking place inside your body at this point raise the first suspicions of pregnancy. The cells, which have by now formed a cluster, attach to the uterus’s wall before getting divided into two parts. One half becomes the placenta: the part from which the developing life will derive its nutrition. The other will develop to form the baby. Your system undergoes an increase in stroke volume during the first trimester. This rise in stroke volume leads to an increased cardiac output over the next few months. The mother should have full knowledge of cardiovascular adaptations, especially in dealing with body positions during exercises. Additionally, the mother’s body temperature decreases by 0.3 ºC during the first trimester.
Second month
The twenty-sixth day after fertilization is officially the day your baby’s heart starts beating. The embryo is now synonymous with a raisin in its shape and size. However, growth occurs rapidly and in no time the external features of the embryo begin to take form. All major organs are formed by now. The tubular growth in embryo’s middle, better known as the neural tube, will develop to become the brain. The placenta too has started functioning. Known as the umbilical cord, the placenta will provide the baby with necessary nourishment all through the pregnancy phase.
The spinal cord or spine develops faster than the remaining parts at this stage and takes the appearance of a tail. At the beginning of the seventh week, the embryo is about 6 mm long. Vital organs like liver and kidneys have begun to take shape and the tube connecting the spinal cord and brain closes down. The leg and arm buds are visible. For the mother, the period will remain fraught with a variety of physical sensations like frequent urination, sore breasts, fatigue and nausea.
As you enter the seventh week of pregnancy, the embryo inside you develops paddle shaped feet and hands. The embryonic tail, on the other hand, is no longer there. The formation of pituitary gland has already begun. The heart, which started beating at the beginning of the 5th week, has divided into two chambers: the left and the right. There are 150 beats in a minute: twice the rate at which a human adult heart beats. The unborn baby now has a tongue and mouth: the first visible facial features. Since the vital muscle system is now developed, it gives your baby the ability to practice movements.
Last but not the least, the baby, by now, has a blood type. Life style choices made by the mother at this stage are likely to have a huge impact on the developing baby. The use of alcohol, drugs and toxic substances can make a difference to the baby’s development. It is also advisable for the mother to stay away from street or prescription drugs during this phase.
Third month
The life developing inside you has a new name now: the fetus. Protected by an amniotic sac, the fetus is stuffed within fluid. The child moves and swims happily inside. The fetus is about half an inch long now. During this phase, the baby’s head appears much bigger than the body. The palate and teeth have just begun to form and so has the larynx. The unborn baby’s veins are quite visible through the thin layers of skin.
At the beginning of the ninth week, the fetus starts moving around frequently. The nerves, muscles and organs are all in place and function normally. The paddle like shape of hands and feet is almost gone as toes and fingers begin to take shape. By the beginning of the tenth week, the fetus is about one-third of an ounce heavy. The near-developed heart resembles that of a baby. Ankles and wrists have formed.
Although, a fetus in the tenth week of pregnancy has genitals, its gender is probably too early to detect. As the eleventh week begins, the development of intestines, kidneys, lungs and brain come full circle. The head, by this time, grows to about half the size of the entire body. In the twelfth and last week of the first trimester, the baby’s vocal chords take full shape. This enables the baby to cry silently at times. Its brain fully formed, the baby can even feel pain during the last week of the first trimester. The kidneys, on the other hand, have developed well to secrete urine.
As you graduate to the 2nd trimester, things start getting more and more complex. To many, the months of the first trimester form the best phase of pregnancy. A majority of women spend the first trimester in a stage of shock and awe. However, as days go by, the mother slowly starts adjusting to and enjoying the new phase. Apart from frequent mood swings, an expectant mother in her second and third trimesters experiences a plethora of physiological challenges. Nothing the mother faces, though, can overshadow the sheer joy of becoming a mother. So here’s wishing you a happy and healthy pregnancy ahead!