Within the female body lies a fascinating organ that holds immense power and significance for the creation of life: the uterus. While most of us are familiar with its basic functions, such as housing a developing foetus during pregnancy, there is so much more to this mind-blowing organ than meets the eye. Here are 10 amazing facts about the uterus!
1. The uterus prepares for pregnancy every month
Each month the uterus prepares for pregnancy by creating a thick lining to welcome and fertilise an egg. If an egg doesn’t embed itself into this lining, the lining breaks down and menstruation occurs. In a woman’s entire reproductive life, her uterus is all set to be pregnant around 500 times.
2. The uterus is usually no bigger than a pear
Pre-pregnancy, the uterus is a pear-shaped organ (only around 3 inches long and 2 inches wide) that fits snugly under your pubic bone. It sits there, minding its own business – except for structurally supporting your lower organs and triggering menstruation. As we are all unique, the exact shape and size obviously varies among women.
3. The uterus can expand to the size of a watermelon
The uterus is one hell of a stretchy organ. Throughout pregnancy, as baby grows, your uterus changes its shape and size to ensure your baby is perfectly cocooned. It gradually inflates like a balloon up to your rib cage, politely pushing other organs aside, and increases to more than 5 times its pre-pregnancy size, with a capacity up to 500 times more than before!
4. The uterus grows its own organ
This is one of the most incredible qualities of the uterus: it is an organ that literally grows another organ – the placenta. The placenta has the hugely important job of providing nutrients and oxygen to the baby as well as producing the hormones that regulate both maternal and foetal physiology. Once the baby is born, the placenta is then released, as its work is done, and the uterus goes back to just flying solo as a lone organ again.
5. It takes only 6 weeks for the uterus to be back to its pre-pregnancy size and weight
Within minutes of the placenta being released, the smooth inner muscles of the uterus start contracting causing the uterus to shrink. The uterus will be about half the size that it was at term after only 1 week following the birth. After 2 weeks, the uterus is back to being a pelvic organ, and after only 6 weeks, the uterus is back to its pre-pregnancy size and weight.
6. By weight, the uterus is the strongest muscular organ in your body
The uterus is made up of 3 layers of vertical and horizontal muscle fibres that intertwine to create a mighty muscle force that can birth a baby. The pressure and power the uterus employs in labour is the strongest force exerted by any muscle in the body.
7. During pregnancy the cervix is about 1/3 of the thickness of baby’s head
The cervix is the lower, narrow end of the uterus that forms a canal between the uterus and vagina. The cervix’s main function is to act as a barrier separating the uterus. This function is essential for a successful pregnancy to develop as it holds baby in.
During pregnancy, the tight bands of muscles that form the cervix gradually softens. As your body gets ready for labour, the cervix decreases in length, and finally opens as you prepare to give birth.
8. The muscles of the uterus work as a pair during labour surges
During the first stage of labour, the outer and innermost layers of the uterus work as a pair. The inner layer which encircles baby and comes down to form the cervix opens, whilst the outer layer draws up and pull on those horizontal bands of muscles to make space for baby.
9. Some uteruses are shaped like a heart
A heart-shaped uterus is called a bicornuate uterus. Instead of being pear-shaped, the uterus has two bumps sticking up that make it resemble a heart. Approximately 1 in 1,000 women have a bicornuate uterus.
10. Some women have 2 uteruses
1 in 2,000 women have a condition known as uterus didelphys, where the two tubes that usually connect to create one organ, instead each develop into two separate organs. Conversely, 1 in 4,500 women may be born without a uterus, so it’s not an organ to take for granted.
