A Pregnant Uterus

Published : 02/04/2024

Last updated: 14/07/2024

Lets shed some light on the body part that hosts and helps in the development of the tiny human. The Uterus is an amazing organ that can expand from the size of a lemon to as big as a watermelon –in less than 40 weeks and then shrink back down to the original size. This is possible due to its three muscular layer and naturally gifted elasticity. 


Also known as the womb, the uterus is oval shaped and sits between the rectum and bladder. It is also responsible for monthly menstruation, before getting pregnant. Now lets do some size comparison.

Usual size of a uterus

Usually the uterus is about 3 inches long, 2 inches wide and 1 inch thick. Weighs about 1 ounce and in the shape of an upside-down pear.

Uterus size in weeks

This miraculous organ changes its shape and size weighing from 1 ounce in week 1 to 2 pounds around week 40. 

Tapes are used to measure the uterus, from the fundus (highest point of uterus) to the top of pubic bone. Also known as the fundal height (measured in centimeters) this measurement corresponds to how many weeks into pregnancy a new mother is.

Pregnancy Week

1 to 11 weeks

What is Happening

The Uterus is still small, however it is preparing for changes and growth.

Pregnancy Week

12 weeks

What is Happening

It is beginning to grow and starting to go beyond the pubic bone

Uterus size large orange

Pregnancy Week

16 weeks

What is Happening

A noteworthy growth, it can now be felt in the abdomen. Almost halfway between pubic bone and belly button.

Uterus size grapefruit

Pregnancy Week

20 weeks

What is Happening

Top of the uterus can be felt around the belly button. In a couple of weeks it will start to grow at a rate of 1 cm / week.

Uterus size papaya

Pregnancy Week

28 - 40 weeks

What is Happening

Starting from 28th week, the uterus will start feeling as if its pushing up into the ribs.

Uterus size watermelon

Typical positions of uterus

The Uterus can be in a single position of the four mentioned below

Normal Position

Most of us have our uterus, tilting forward at the cervix and pointing towards the abdomen.

Normal position Uterus


The Uterus is bent forward, which can put pressure on our bladder or abdomen, this can cause pain

Anteverted uterus


Commonly known as ’tilted’ uterus, as it tilts backward slightly, curving towards the spine instead of facing the abdomen.

Retroverted uterus


The uterus is bent backward toward the spine, this can put pressure on the lower back portion of the body.

Retroflexed uterus

Uterus reverting its previous size

As soon as the baby comes the uterus starts to contract to go back to its previous size, this process is called uterine involution. The process takes about six weeks at times less than that, and may cause postpartum cramping.


To conclude, the elasticity of the uterus allows it to go from the size of a lemon to the size of a watermelon and then revert back to almost exact previous size, however the process of reverting takes shorter time – all this carried out so that the baby can grow comfortably.

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