The placenta
The The organ in the uterus of pregnant mammals that allows the transfer of nutrients and waste products between the mother and the fetus through the umbilical cord. is an organ responsible for providing oxygen and nutrients, and removing waste substances. It grows into the wall of the uterus and is joined to the fetus by the The cord that connects the foetus to the placenta. It contains blood vessels..
The mother's blood does not mix with the blood of the fetus, but the placenta lets substances pass between the two blood supplies:
- oxygen and nutrients When particles spread out from a region of higher concentration to a region of lower concentration. across the placenta from the mother to the fetus
- carbon dioxide and other waste substances diffuse across the placenta from the fetus to the mother
The mother鈥檚 lifestyle can affect the developing fetus. For example, smoking reduces the amount of oxygen in the bloodstream. This can lead to low birth weight and premature birth (when a baby is born too soon). Drinking alcohol during pregnancy can harm the developing baby鈥檚 nervous system, especially its brain.