To avoid foodborne illnesses during pregnancy, it's important to follow food safety practices: clean hands and surfaces, separate raw and cooked foods, cook to safe temperatures, and refrigerate promptly. Avoid high-risk foods like deli meats, raw eggs, undercooked meat, raw seafood, unpasteurized dairy, sprouts, pates, and unpasteurized juices. Mercury, harmful to the baby's developing brain, is found in high levels in fish like tuna (fresh/frozen), shark, and swordfish; limit these to 150g per month. Canned albacore tuna specifically should be limited to 300g per week, but other species like skipjack are safer and lower in mercury.