How much did you gain in first trimester? First pregnancy I gained 1 kilo in first trimester and I'm on second pregnancy 12 weeks exactly and already gained 5 kilos!!! I'm a bit worried bc first pregnancy I gained total 23 kilos! This time around I want to gain less. I am tall and usually thin. I guess I need to cut back on eating so much! I have been eating more bc this time around feeling sick every day and eating helps w the tummy sickness.