You can see from the image above why the placenta is commonly referred to as the “tree of life”.

Did you know that the placenta is probably the second most fascinating and amazing thing you can grow, after your baby of course! I highly recommend that after the birth, you take some time to become acquainted with your placenta; don’t be afraid to ask your caregiver to give you the grand tour – usually the midwife will jump at the chance to show you.

During my research for this post, I discovered that ‘placenta’ comes from the Greek word ‘plakuos’ which means “flat cake” – I love this visual!

The placenta is actually a transient organ, meaning that it will leave your body once its purpose has been fulfilled, which is the nourishment of your baby while they are inside your womb (uterus). The life of the placenta begins alongside that of your baby – once the embryo has implanted into the wall of the uterus, some of the cells embed deeper into the innermost layer and develop into the placenta. For the first 3 months, the development of the placenta is gradual and after the 4th month, the placenta grows at the same rate as the uterus, which increases in size to accommodate the growing baby.

The placenta is highly unique, in that it performs many functions which are eventually taken over by other organs such as the lungs, kidneys and stomach once the baby has been born. The placenta takes oxygen and nutrients from the mother and delivers these to the developing baby, whilst also removing waste products which are transferred back to the mother and eliminated through her urine. This all happens via the umbilical cord which is made up of two veins and one artery and connects the baby to the placenta at the navel (this will become the site of the belly button after birth). The blood vessels inside the cord are surrounded by a thick, protective substance called Wharton’s Jelly.

The way in which this exchange of nutrients happens is quite complex. There is no physical mixing of the mother’s blood and the baby’s blood – the two systems remain completely separated by extremely thin membranes. Scientists have discovered that this membrane can be as thin as 0.002mm. To put this into perspective, a piece of paper is approximately 50 times thicker than this!

If we think back to the “flat cake” visual from the Greek origin, the placenta has two sides – one which belongs to the baby and one which belongs to the mother. There is a space between the two sides, into which blood from the mother’s circulation collects. The arteries and vein from the umbilical cord branch off inside the main body of the placenta, creating many tree-like structures which grow through the baby’s side of the placenta and are then bathed in the blood which pools in this space. This is where the magic happens!

The exchange of nutrients is done through the process of diffusion, where molecules such as oxygen, glucose and vitamins present in the mother’s blood move across the membranes of those tree-like structures into the baby’s system. These nutrients are then carried to the developing baby via the umbilical vein. The process then works in reverse with the umbilical arteries being responsible for the removal of deoxygenated blood (blood which essentially needs “refilling” with nutrients) and waste products from the baby– these substances move across the membranes from the baby’s system into the mother’s circulation via the same blood pool and these are then excreted through the mother’s urine.

Once the baby is born, the placenta must follow! If your baby has been born vaginally then you will also have to birth the placenta. If you have had a caesarean section, the placenta will be surgically removed by the obstetrician. The placenta is always examined by your healthcare professional after the birth to ensure that it is whole and that nothing has been left inside. It will also be checked for any interesting or unusual features – any findings will be shared with you. Your placenta is your property, and many couples are now choosing to take theirs home with them. Lotus births and placental encapsulation are becoming very popular so you may wish to do some reading on your options.

There are many cultures who revere the placenta due to its ability to sustain life, and it has important cultural significance for many across the globe. During my time working as a student midwife in New Zealand, I was stunned to learn it was standard practice in the hospital that every woman was given their placenta to take home with them. In western culture, the placenta is usually regarded as nothing more than hospital waste. In Maori culture the word for placenta is the same word used for land – “whenua”. The placenta is buried and returned to the land in a place of ancestral significance for the family. In Madagascar, the placenta is considered holy, as it provides the baby with everything required to grow and flourish inside the womb. The placenta is buried close to the entrance of the family’s house so that all who enter the home connect with this sacredness. In some Israeli Muslim communities, the placenta is treated with salt before being hung above the doorway to the family home to warn off the demoness Qarinah, again reflecting deep religious significance.