The amazing placenta
We often don't get told a lot about our placenta, but it's a rather impressive temporary organ for the nourishment and protection of baby.
Your placenta starts to form on "implantation", into your uterus, with a network of blood vessels. These blood vessels ensure a transfer of blood, oxygen and nutrients. The placenta also produces hormones such as hcG, estrogen and progesterone. On the side of baby, this flat, bowl-like organ has the umbilical cord attached, which contains one umbilical vein and two umbilical arteries. The single vein carries oxygen-rich blood from the placenta to the baby and the arteries carry de-oxygenated blood and waste from the baby back to the placenta.
The placenta is unique in receiving blood supplies from both the maternal and fetal circulatory system. It has two separate systems for blood- maternal-placental and fetal-placental- pretty impressive, hey!?! It's a disc shape that can span up to 22 centimetres in diameters.
Wonder why you get so exhausted late in pregnancy? Your body is doing amazing work in growing and supporting baby. Your blood flow to the placenta is approximately 600–700 ml/minute at term gestation (38-42 weeks of pregnancy).
How does the placenta release after birth?
Some time after baby is born, the placenta ceases in its support of baby, as the baby's lungs become oxygenated and it breaths independently (it is still very important to continue to have toe ord attached until all the blood is drained from the placenta, even though baby is breathing independently). Things like undisturbed birth and skin to skin help in oxytocin production, which in turn helps the uterus contract. The blood vessels that were once attached to your uterus wall become restricted and release from the uterus wall. The placenta, which is sponge-like, will peal away and be "born".
Below: my 5th baby, Nora with her cord yet to be cut. This was a decent size placenta! Image: Bron from Kindred Birth.