The major component of marijuana, tetrahydrocannabinol, can cross the placenta and thus may have an result on the fetus. However, use of a small amount of marijuana does not appear to extend the chance of delivery defects or to slow the expansion of the fetus. However, whether cocaine is the reason for these problems is unclear. For example, the cause could also be other risk factors which are widespread in women who use cocaine. Such components embody cigarette smoking, use of other illicit medication, deficient prenatal care, and poverty.