DL: What about fish?

VM: You want to reduce exposure to mercury—abundant in shark, swordfish, king mackerel, and tilefish—because it’s a neurotoxin and a developing fetus’s nervous system is exquisitely sensitive in the first weeks of pregnancy. But you don’t want to avoid all fish because it’s the best source of omega-3 fatty acids, which are critical to baby’s brain development and can help prevent postpartum depression. I recommend enjoying two to three meals a week with wild salmon, sardines, herring, or black cod.