Thank you! :D

The question is very interesting, but there is no certain answers. To date we have not yet been able to observe the effects on a hypothetical fourth generation in humans, and certainly will be done in the future. But animal models seem to suggest that there are mechanisms at the level of the zygote that prevent the passage of epigenetic information beyond the third generation (at least in mammals).

I think there is still so much to discover about it, we know very little.