Thanks for your query,
cannabis or weed has several detrimental effects on growing fetus.
There is intrautrine growth retardation as weed interfere with blood supply to fetus and deprive him of oxygen
.IUGR babies have their own problems of jaundice
,infections and many more.
There is increased chances of SIDS(sudden infant death syndrome
Delayed development milestones.
Hyperactive behavior,learning and memory problems.
Eating good food,taking vitamins will not do any good to fetus.
So i advise to quit smoking for better health of mother and child,