Short Answer: Mostly to your growing baby and stored fat for delivery and breastfeeding.

Here’s the complete breakdown:

  • Baby: 8 pounds
  • Stored fat for delivery and breastfeeding: 5-9 pounds
  • Placenta: 2-3 pounds
  • Amniotic fluid: 2-3 pounds
  • Breast tissue: 2-3 pounds
  • Blood supply: 4 pounds
  • Larger uterus: 2-5 pounds

Total: 25-35 pounds

If you’re concerned about what foods to eat, and what foods to avoid when pregnant, you can check out What To Expect: Eating Well When You’re Expecting.