First Trimester: Here’s what you need to know


The first trimester is a period of pregnancy from conception until 12 weeks.

It is a very important time as your baby’s organs develop, and it is during this time that the fetus is most at risk to damage from illnesses, certain medications, viruses and lifestyle abuses such as alcohol and smoking as well as chromosomal mutations.

Let’s see how your baby develops in the first trimester

 Within hours of fertilization the egg splits into 2 then again into 4 cells, and by the 4th day after fertilization, it becomes a group of about 16 to 20 cells.

By the 5th day, it creates a bunched up group of cells on one side and a sac of fluid on the other.

All this happens as the fertilized egg is journeying through the fallopian tube towards the uterus.

It then enters the uterus and implants itself into the lining of the uterus about 1 week before the next period is due.

4 -5 weeks:

The baby’s spinal cord and brain called the neural tube begin to form.

The yolk sac and a body stalk, the beginning of the umbilical cord, also get formed

5 – 6 weeks:

The heart forms.

6 -7 weeks:

The lower and upper jaw form and the baby develops bulging eyes on each side of the head.

7 -8 weeks:

The baby now forms arms and then legs; the oesophagus, stomach, kidneys and bowel are being defined, as well as 2 small buds which will grow into the baby’s lungs. The heart now has four chambers and beats between 90 and 200 times per minute.

8 – 9 weeks:

The cheeks, mouth, lips and chin are more defined and the nasal passages too have started forming, creating the tip of the nose.

Eyelids develop this week; they will however remain fused until the 24th week of development.

Ears start to form too; however hearing will only start in the 5th month.

Taste buds form on the tongue.

Many tiny blood vessels can be seen networking through the body below the translucent skin.

The skeleton also develops further.

9 – 10 weeks:


The baby now has separate fingers and toes and nail beds are starting to form; the actual nails will only grow after about 20 weeks

The liver is now producing blood cells.

Elbows, knees, wrists and ankles too have started developing.

External sex organs are just beginning to form.

10 -11 weeks:

The baby can suck and swallow.

Taste buds have also developed.

Kidneys are now functioning and secreting fluid into the bladder.

The baby also begins to breathe.

About 20 baby teeth are now in the gums.

11 -12 weeks:

Bones now become harder. The baby can make creeping and climbing movements.

Very fine wisps of hair now start appearing on your baby’s upper lip and eyebrows.

The baby’s bowels are now able to expand and contract.

You do need to look after yourself….

There’s a 20-40% chance of first trimester miscarriages, the major causes of which are chromosomal anomalies, hormonal deficiency and certain viral infections.

Do’s and Don’ts for the first trimester:




Eat small meals. Avoid warm places as they may increase your nausea.


Drink small amounts of fluid throughout the day to avoid dehydration. Do not eat spicy food or lie down immediately after eating.
Try eating dry rusk or crackers 15 – 20 mins before getting out of bed in the morning. Skipping meals may also aggravate the symptoms.



If cooking odours bother you then put on the fan to dissipate them.


Avoid raw meat and fish.


Sipping ginger water can help.


Avoid unnecessarily strenuous activity.



Mild exercise, such as walking is good.


Supplement your pregnancy with folic acid.




Morning sickness is a common symptom and starts at about 6-7 weeks of pregnancy with nausea and/or vomiting, although many do not experience it at all.

Like I said before the first 12 weeks of every pregnancy are very important in determining the health of the baby. So if you are in your first trimester, take care and stay positive. You have just begun what will probably be your most fulfilling journey yet.

Dr. Rajul Matkar is an internationally-recognized Obstetrician & Gynaecologist, with 27 years of clinical experience. She has received specialized training in minimally-invasive gynaecologic surgery from Kiel University, Germany, and has completed training for advanced colposcopy and directed procedures under the British Society for Colpo Cervical Pathology (BSCCP).

Dr. Matkar is a respected and sought-after source for the popular press and has been quoted in several publications in India and abroad. She has also given talks at various scientific institutes in the UAE.


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