The placenta also serves as a lung for children and allows you to pass on oxygen to your baby. The placenta returns your babys biological waste to the moms circulation system, which is later removed from your body through urine. Throughout pregnancy, the placenta retains the main role of all biological membranes (i.). The placenta often develops low in the womb, but moves to the side or upward as the uterus stretches. The position of the placenta will be checked on your 18-week ultrasound. It is widely believed that during normal pregnancy, the placenta gradually increases and is on the verge of a transition to morphological and physiological aging. It forms and grows where the fertilized egg attaches to the wall of the uterus. The umbilical cord grows from the placenta to the babys navel. A mature placenta was once thought to be an important finding and increase the risk to the pregnancy. However, we do not believe it really is a very important finding anymore. Now, having said that, if you have any high risk factors like smoking, then it may mean something. the risk for placenta accreta increases with each pregnancy. If you have placenta previa, your risk of placenta accreta increases. In the past, placenta accreta often wasnt diagnosed until after the baby was delivered. the placenta is a vital organ during pregnancy, so having a calcified placenta in pregnancy could be dangerous to you and your baby if it occurs several weeks before your due date. In the third trimester, it is normal and expected that your placenta is aging, and it should be at a grade iii. If you were in the second trimester, an aging placenta would be worrisome. What does an ageing placenta or calcification of the placenta mean? Placental calcification is the medical term for some of the changes that happen to the placenta, as pregnancy progresses. Many researchers regard placental calcification as a normal ageing process, rather than a change related to a disease or ailment. The placenta is usually described as going through four grades, from 0. The mature placenta is disklike in shape, 3 cm thick, and about 20 cm in diameter. The fetal side of the placenta is shiny because of the apposed amniotic membrane.