- The uterus becomes heavy during pregnancy (baby + amniotic fluid + placenta) and puts pressure on the cervix. Jumping and running can cause impact between the uterus and cervix, and could cause preterm labor. Women vary in their ability to handle these activities during pregnancy, so the main thing is to listen to your body and STOP if it feels uncomfortable, especially if you experience any contractions. The only risk to the baby here is being born too early, not physical injury from the impact of mom jumping. As I mentioned in my last post, running is no longer comfortable for me, so I no longer run. I still feel good doing box jumps and double unders, so I still do them. If/when they become uncomfortable, I will stop.
I'm not sure what type of injuries my critic is concerned about with push press, but in my opinion light to moderate weight push press (which is what 75# is for me) is one of the safest exercises to do while pregnant.
http://www.crossfitmom.com/ (particularly the forum Q&A)
Obviously I don't agree with everything these sources say to avoid doing while pregnant, but the point is none of them say "jumping is bad because you are shaking the baby and can cause brain damage."
72 days to go!