Health Pregnancy

Pregnancy Week By Week: First Trimester of Pregnancy

This pregnancy timetable is a week by week chart. It’s very helpful for parents who are keen to know about the level of growth of their baby.

With the help of pregnancy calendar, you will keeps proper information about the growth of your baby . Simultaneously pregnant mom can get information regarding the changes during pregnancy .

What is the first trimester?

With the help of pregnancy calendar, she can care of growth of her baby in every stage.

  • Total days of pregnancy: 40 weeks (Gestation period)
  • Age of delivered baby: 38 weeks.

Since the duration of pregnancy is calculated from the first day to last day. At the end of the second week, only fertilization would have taken place.

So the delivery of the baby will be around 38-42 weeks which is considered to be normal.

First Trimester of Pregnancy: Week 1 to 12

Week 1 of Pregnancy:

Since the period of pregnancy is calculated from the first day of your last menstrual periods. This week comprises of the menstrual period only. But during this period baby has not been conceived yet.

What to avoid during the first trimester?

  • During first trimester, Drugs and alcohol should be avoided.
  •  With out doctors advice, you should not take any types of medicines.
  •  During pregnancy should follow proper diet, which are full of vitamins or multivitamin.

Week 2 of Pregnancy:

By the end of this week, ovulation takes place that is the release of an egg from the ovary. If at all a sperm is available in the Fallopian tube there are more chances for fertilization.

Sperm has to undergo a lot of preparatory changes in itself before it enters the egg. Once it enters the egg there will be changes in the outer portion of the egg preventing other sperms to fuse further.

During this fusion, only the gender of the baby is established. Male sperm has two chromosome types X and Y. The female egg has an only X chromosome.

Hence if,

Male(X) +Female (X) = baby girl.

Male(Y) + Female (Y) = baby boy.

This stage of embryo is called Zygote.

Week 3 of Pregnancy:

After 30 hours of formation of the zygote, there starts the division of the cells. The two cell of body divides into

  • 2 cell stage.
  • 4 cell stage.
  • 8 cell stage.

Stages Of Pregnancy

During this stage, it starts moving from the fallopian tube to the uterus wall. In this stage, it looks like a ball of cells called Morula. The further division takes place leading to the formation of Blastocyst.

The outer most layer is called trophoblast which gets attached to the endometrium of the uterus. This important process of attachment is called implantation.

It is this endometrium that provides nutrition to the embryo at this stage. This implantation site later develops into the placenta.

Care for the mom

At the time of implantation, there will be spotting of blood called implantation bleeding.

Since the embryo starts taking nutrition from the mother. It is important to enrich the mother’s food with protein (For cell division) and iron, calcium etc.

Week 4 of Pregnancy:

During this stage the embryo comprises of:

  • Epiblast & Hypoblast.
  • Amnion & Yolk sac.

The former is involved in the formation of body organs. The latter amnion helps in protection with amniotic fluid forming a cushion like support and yolk sac forms blood and nourishes the embryo until the placenta takes over that role.

Week 5 of Pregnancy: 

Until this stage, the embryo looks like a cell mass and later this it takes up a definite shape. By this time it will be a size of a grain.

  • The upper portion of the embryo develops into neural tube which later forms the brain and nervous components later.
  • A bulge appears in the center which later forms a heart.
  • The placenta starts developing with a lot of finger like projection called microvillus which increases the area of absorption.

Care for the mom:

From this stage onward other symptoms of pregnancy show up.
She tends to have morning sickness and an unusual craving for food.
Chances of miscarriages increase due to food borne illnesses.

Hence a mother should be very careful in selecting her food and any allergic food items should be completely avoided.

Week 6 of Pregnancy:
By this week the size of the baby will be 3-4 mm.

  • There is a rapid growth of neural components like brain and spinal cord this stage is very important.
  • In the head portion of the embryo on the lateral aspects, two depressions called vesicles develop which further develops into eyes.
  • Still farther from the vesicles there develops passage ways for the development of ears.
  • Heart formation is progressing with the first heartbeat started.
  • There are signs of developing respiratory and digestive systems.
  • Small buds start appearing in the upper and lower half representing the future arms and legs.

Care for the mom:

  • The heart starts beating and can be seen in the ultrasound.
  • Digestion will be affected due to the activities of the various hormones.
  • Food has to be enriched with protein, vitamins, and minerals.
  • There may be loss of weight which occurs in many mothers due to morning sickness and improper digestion. But care should be taken to maintain healthy levels.
  • The typical symptoms of breast sore and tenderness start here.
  • Increased frequency of urination due to the extra fluid kidney has to excrete.
  • Fatigue dominates everything due to the increased demand from the embryo.

Week 7 of Pregnancy:

There is the incredible growth of the embryo from the size of 4-5 mm at the start of the week to 1-1.3 cm at the end of the week.

  • The hand and leg buds that appear earlier grow longer with well differentiable arms, shoulders and hands.
  • Digital plates too develop forming the fingers and toes subsequently.
  • There is appreciable formation of chambers of the heart.
  • There appears primary bronchus which carries oxygen to the lungs.
  • The brain has well distinguished cerebral hemispheres. The development of eyes and nostrils are remarkable.
  • Appendix, pancreas and intestines also start forming.

Care for the mom:

  • There seems to be a little weight gain.
  • Women consume those foods,which are full of Calcium and vitamin-D that are important for bone formation.

Week 8 of Pregnancy:

The size of the embryo will be around 1.6 cm and it’s of 1 gram weight.

  • Eyelids are forming in this stage and retina of the eye develops with nerve cells in it.
  • Both external and internal ears are forming.
  • The tip of the nose is developed.
  • There are distinctions between arms and forearms with the formation of the elbow.
  • Chambers of the heart are developing with valves in between them.

Care for the mom:

  • The size of the uterus is increasing gradually.
  • As it grows there will be cramping accompanied with vaginal bleeding.

Week 9 of Pregnancy:

The size of the embryo is now around 2.3 cm and weighs around 2 grams.

  • The embryo starts looking like a human form not like a cell mass or tadpole like.
  • The eyelids are completely growth and cover the eyes.
  • Fingers have developed completely and the hands remain flexed.
  • The head is now straighter as the formation of neck progresses.
  • There starts a mild movement of the baby.

How can I stay healthy during the first trimester?

Vitamin C and Iron are very important during pregnancy. Most  of the women tend to become anemic.

Hence women intake those foods, which are high in iron. Iron is rich include

  • green leafy vegetables,
  • liver,
  • egg,
  • date fruits,
  • grapes,
  • dry fruits etc.

What happens to the fetus during the first trimester?

Week 10 of Pregnancy:

The size of the baby increases to 3.1 cm and it weighs around 4 grams.

The end of this week is the end of the embryonic period of pregnancy, and the Fetal period begins.

This stage is most important for the rapid growth of the fetus. During this period the fetus is most susceptible to factors that could interfere with its development.

Care for the mom:

Taking in protein during pregnancy will provide amino acids that are essential for the growth and repair of the fetus, placenta, uterus and breasts.

Protein is rich in Soya and its products, legumes, egg, meat etc.
However, protein should only make up about 15% of your total calorie intake during pregnancy.

Week 11 of Pregnancy:

The size of the baby measures 3.1 cm and weighs 4.5grams.

Fetal growth is rapid now and baby’s crown to end length will double. At this stage baby’s head is almost double the length of the baby’s entire length.

As the head straightens the chin lifts from its chest and the neck will start to strengthen and develop.

External genitalia is beginning to show distinguishing features. At the end of the next few weeks, the transformation into either a boy or a girl will be complete.

Week 12 of Pregnancy:

  • The size of the baby will be around 5.4cm and weigh about 14 grams.
  • Fingers and toes which remain fused so far get separated.
  • External genitals are formed and can be seen in ultrasounds.
  • There are centers of bone formation that further helps in the growth of the bone.
  • The pituitary gland which is the master of the gland starts producing hormone.
  • Digestive alimentary tract has been formed and it can push the food forward.

Care for the mom:

  • Size if the uterus keeps on increasing and it’s bigger enough to be inside the pelvis and it can felt above the pubic bone.
  • Bone formation is active and intake of calcium and vitamin D should be sufficient.

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