THC, the psychoactive elements in marijuana are known to pass from the mother to the developing fetus through the placenta. Smoking marijuana during pregnancy may affect your baby’s growth and the development of his nervous system. The children of heavy marijuana users may also have short-term memory, concentration and judgment. Any form of smoking can disrupt the supply of oxygen and nutrients to the fetus, which can result in restriction in the growth of the fetus including, overall length, foot length, head size, body weight premature birth, stillbirth, and miscarriage. A woman who smokes during pregnancy is more life to giving birth to babes with some illnesses.