weight gain breakdown

I see so many posts on here where women are concerned about weight gain during pregnancy. It is very easy to keep yourself informed on topics like this. March of Dimes, APA, and many other sources will give you a breakdown of the weight you are gaining. You are SUPPOSED to gain weight when you are pregnant. 
For a 30 lb weight gain, here is the breakdown: 
Baby-7.5 lbs
Amniotic fluid-2 lbs
Blood-4 lbs
Body fluids-4 lbs
Breasts-2 lbs
Fat, protein and other nutrients-7 lbs
Placenta-1.5 lbs 
Uterus-2 lbs
People who were underweight before getting pregnant are also supposed to gain more than people who were overweight. In this "fake news" climate please keep yourself informed.