Hamburgers must be cooked to an internal temperature of 160°F (well-done) during pregnancy. Unlike whole cuts of beef, ground meat can harbor bacteria throughout. No pink should be visible. Pre-formed frozen patties should also be cooked to 160°F.
A "Use Caution" rating means this food is generally fine during pregnancy but comes with a specific factor worth managing — a daily limit, a preparation requirement, or a moderation guideline — rather than a reason to avoid it outright. These ratings reflect general guidance from the FDA, ACOG, CDC, and USDA. The goal of the "caution" label is to flag what to pay attention to, not to suggest the food is unsafe when that factor is properly managed.