I've heard this comment before, a doctor saying it's ok to smoke pot. Unbelievable, such a person could make this statement. If it's killing your brain cells, it's killing any brain cells the baby is trying to develop inside the womb. Smoking restricts the blood flow to the Babies brain. The baby can't say stop mum your hurting me, but you can make the choice to say, IM not going to hurt my baby by smoking pot while pregnant. No drug or alcohol is the smart thing to do. Don't let anyone tell you different, every drug is a mood enhancer, it changes the way you feel, it's chemicals have the ability to give you a high or low with you having no control over it, so of coarse the baby will be affected in some way. Weather it's during or after delivery or when the child is at school not being able to function on his/her school work. There are consequences for any drug use in pregnancy, you may just not see them straight away. Best of luck to you both. I hope you can kick this habit. And listen to your heart, you do what feels right for yourself and your baby.
Not only is the action of smoking itself is detrimental to the health of the baby, but we do not know how cannabis intake can affect the developing brain. This is not a bias opinion, but a medical one. We know for a fact that cannabis use decreases IQ in adults by about 10 points. Are you willing to bet your child's intelligence for the sake of your indulgence? Everything you ingest or otherwise put into your body crosses placental barrier right into the baby.
You want to eat right and stay away from all unneeded drugs and alcohol while you are pregnant and nursing or mothering young children. Please take good care of yourself and that way you can be sure you are taking the best care of your child! I do hope I am not being too judgmental here.