i don't have time to read all the responses right now, but just wanted to chime in that i've had phases of moderate pot smoking throughout my life & have used it medicinally for an upset tummy or headaches or similar such tings. BUT, i used to get really severe period cramps & actually found that it did not help with that at all. in fact, i found myself focusing on the pain more. for me, it was not good for that kind of pain at all. although in california i believe you can get a medial marijuana card for that specific complaint, so it must work for some women...
I hate it when people say "I tried pot and it didn't work" or "I ttried pot and this happened that I didn't like" because I'm sure that if we had access to the strain names when we bought it and researched when strain families we were looking for I believe that pot would definately relieve almost any symptom. It really is like saying you don't like apples if all you'vwe tried are the ones off the tree in your back yard. Unfortunately people doin't know this, don't ask, and are often unwilling to pay the extra money because they believe that the pot is just stronger when really it is completely different that the cheap stuff most people have access to.
If you seek out the information about strains it really is easily accessable, and if you demand to know the strain names from your dealers you are eccentially empowering the whole pot community to take responsibility for what strains are bought and sold and how effectively it is communicated. You discuss medications effects with your pharmasist, discuss you medication with the dealer too, if they don't know the answers tell them they should either find out or they are losing a customer. Often dealers just don't tell you because they think you don't care and don't understand that you are treating something instead of using it to get high like most of their customers.
So that brings up the conversation of what strain would be most effective for labor. But you can't answer that because everyone wants something different for labor. One mom may want pain relief, while another may want internal focus, or higher senstivity to better connect with the birthing epereince, while another mom my want to zone out so she can let her body take over while she can still "sit back" and observe the miricle.