My former doctor suggested micronized estradiol sublingually to avoid first pass effect. My current physician suggested to just swallow them whole as sublingual administration creates larger variance in serum estrogen levels (as Sammy stated.) She feels swallowed tablets provide a more consistent and predictable dosing. This is based on my risk factors which, outside my age (42) are minimal, (excellent liver function tests, non drinker, non smoker, consistent weight loss, etc.) She said not to worry about first pass, let the liver do its job.
This is my experience only, so please ask your physician about it as they will be able to apply current research to your medical profile.