In short, according to public-health guidance, albacore (white) tuna is best limited during pregnancy.
Why
Moderate mercury
What to do
limit to 4 oz (112 g) per week — FDA lists albacore as a 'Good Choice', 1 serving a week
The rest of the guidance
Most people checking one food have two or three more in mind. Here is the whole list, strictest first — each verdict is the same one published on that food's own page.