How Long is First Trimester of Pregnancy?

how long is first trimester during pregnancy

You might not look pregnant, but there are chances you are already! You will see changes in your body as the body of a female starts preparing for the arrival of the baby. Symptoms like fatigue, aches and pains might be bothering you. Be happy, you are growing a child. These are just temporary discomforts which are an incredible part of the process which is happening inside of you! If you are a new parent, you might want to keep up with all the exciting developments happening inside of you during each week of the pregnancy. So, the first question that would be running in your mind is how long is first trimester? Let’s find it out:

how long is first trimester recap

How long is First Trimester?

The first trimester lasts from week 1 of the pregnancy all the way to the end of week 13. The baby in the first trimester grows from one sterilized cell called zygote to an embryo which implants on the uterine wall. It further grows into a peach sized bundle of limbs and then body systems. The organs, later on, take shape and eventually the baby starts moving. 

How long is first trimester and how will your baby be growing? Here are some of the highlights:


As you reach week 6, the arms, hands, feet and legs of the baby start to sprout out. By week 10, the fingers and toes will start appearing too.

Hair & Nails

By week 5, the skin starts forming. When the baby reaches week 8, the hair follicles and nail beds begin forming.

Digestive System

The intestines of the baby start forming by week 8. Your baby will already have two sets of kidney developed.

Sense of Touch

As the week 8 arrives, your baby will already have touch receptors on the face, probably on the lip and nose area. Around week 12, your baby will have receptors on palms, feet soles, and genitals.


By week 5, the heart of the baby will start beating spontaneously. The heartbeat will become stronger as days will pass and by week 9, depending on the position of the baby, you will start hearing the heartbeat loud and clear.


The brain of the baby will start wiggling in the developing stage by week 8.


The optic nerves passing from the eyes to the brain start developing by week 4 and the lenses start forming too. However, the retina begins forming by week 8.

After finding out how long is first trimester, new parents start keeping track of every single day, because each day counts. Apart from the major milestones mentioned above, muscles formation, production of white blood cells and vocal cords also begin. Along with these developments, you will observe changes in your body too. Some of these include morning sickness, tender breasts, and mood swings. Your baby is surely going to be small in the first trimester, so you will be gaining only 3 to 4 pounds.

Here is a great idea, as you now know how long is first trimester, get a dairy and write down the experience of each week!



Related posts