A MW acquaintance of mine recommends that all her mamas eliminate gluten & dairy and those that do have significantly easier deliveries.
Having great posture habits make pregnancy and birth way easier, and good endurance and strength, squatting muscles especially.
I can vouch for grain and dairy free being good all around, we made that switch and our energy levels got better, digestive problems went away for DH, aches and pains and headaches all gone, and our weight went down without any portion restrictions (I carried a little extra weight before, my husband a lot extra). The "paleo" recipes and recommendations are pretty good but it's flexible don't worry about anybody's rules if you try it. It goes hand in hand with the WAPF good fats information, but goes farther to replace starches and inflammatory stuff with nutrient rich foods.