Hi Johannah,
Great question! I don’t see too many pregnant women so it never crossed my mind about doing sinew channel treatments on them.
I guess the uterus is one of the tissues that is affected by Wei Qi and sinew channel treatments along with the heart, and the gut, but I think the liver and spleen sinew channels would be more involved with the uterus. If we are working with the bladder sinew channel on the low back, for example, I think as long as the pregnancy is a healthy and secure, it should be okay. It’s kind of like the whole Sp6 debate or Li4 for that matter. I was in a seminar with Debra Betts once and she said it’s perfectly safe to use these points if one feels the pregnancy is healthy and ideally no previous history of miscarriages. I have used Sp6 in the past, not heavy handed stimulation, just gentle needling and no issues.
Anyway, I am really just thinking out loud here and will wait for a confirmation from others 🙂