After fertilisation, the uterine lining becomes thicker. The growing embryo is well-nourished by the blood flow. The placenta, a unique tissue that is embedded in the uterine wall and helps the embryo in obtaining nutrition from the mother’s tissue, is present during pregnancy. The placenta has blood space on the mother’s side and frequently applied on the embryo side . The space between the mother and the embryo is greatly increased by this gap, which also allows for waste removal.