I had severe HG with my first two pregnancies (in the hospital every few days with an IV for drugs and fluids). I was diagnosed Celiac after my second child was born. I avoided all gluten and got pregnant a third time after a year and was hospitalized only twice! I didn't gain any weight with the first two pregnancies but gained 30 lbs with the third. What a difference! Definite link in my experiences between gut health and pregnancy health.