Jailing is not the answer, no, but throwing in "[m]arijuana may not even harm fetuses" is not the kind of message we want to be sending. One of my professors is a leading expert in cannabis research in Canada, and he is currently studying the effects of cannabis on fetal development in rats. They and previous studies are finding/have found increased anxiety and decreased cognition and sociability in rat pups exposed in utero, with worse effects in females than males. Other studies have found some physical deformations I believe, but I'm not so familiar with their research. My professor is studying this specifically because of the extent of its use in pregnancy and his concern with the long-term and large-scale effects of this. Cannabis is a drug and should not be used –
without exception – in pregnancy until its safety and efficacy is established. I sympathise with women in a tough situation, but it's simply not fair to the children. I just think throwing in these kinds of phrases is dismissive of rational concerns, even if the responses to these concerns are irrational.