Board Thread:Manga/@comment-27125793-20190202152111/@comment-36307699-20200613103952

Eden Ushinatta wrote: Yelena is involved. The fact that she told Eren Zeke's true plan was what led to Eren instructing Historia to get pregnant. That can be true, after all, we truly don't know on what Eren Yeager and Yelena were talking about when they met in secret Ten months ago. However, there is also a possibility that some other factor were involve perhaps.

Oh well, we just have to wait see I guest. We probably learn something about this in the aftermath.