Can pregnant women ride a lawn mower during first trimester?

Yes, a woman that is carrying a baby should act and do normal activities. If there are health issues, I would consult your obstetrician. Being pregnant should not stop you from enjoying any activities. I went rock climbing when I was in my fist trimester. You are pregnant not dead, before grocery stores, you would have been working in the field, on the farm until you dropped your little package.