Just read on the back of it it says:

"Provides tuna oil to promote healthy brain and visual development" and says "The tuna oil in Blackmores Preg & BF Gold is tested for mercury, pesticide residues and heavy metals to ensure you can take it with confidence".

Hope that helps thats all I can really say. I got Blackmores because it was 1. on sale 2. the one my nana bought me and 3. I can't find ellevit anywhere lol