Marijuana has several effects on an unborn baby. Marijuana has several street names such as pot, weed, grass, and reefer. When the mother smokes marijuana while being pregnant the drugs cross the placenta to the unborn baby. Marijuana contains many toxins that keep the baby from getting oxygen that he/she needs to grow. Using drugs may lead to other things like smoking tobacco and using alcohol. Marijuana increases the levels of carbon monoxide and carbon dioxide in the blood. This cuts the baby’s oxygen supply down. Marijuana increases the chances of having a miscarriage, low birth weight, premature births and development delays, and behavioral and learning problems.