tobacco smoke contains carbon monoxide, nicotine and tar.
when a pregnant women smokes, carbon monoxide and nicotine diffuse from her blood into the fetus' blood which makes the fetus a druggie too 😂
Carbon Monoxide
reduces the amount of oxygen that haemoglobin can transport meaning the fetus' cells get less oxygen, so they can't respire as much and they cannot release as much energy as usual.
this would affect the development of the fetus and babies born to smokers tend to be smaller then normal.
Nicotine
is an addictive drug which can damage blood vessels so it is not good for the blood of a developing fetus.
many countries' ciggies come with health warnings and a warning for pregnant women.