User blog comment:B214/Volume 23 discussion blog/@comment-201.215.165.7-20170503030001/@comment-82.58.59.197-20170503221508

To be precise, we can deduce it. in High School DxD EX it's said that they come from the future 30 years ahead. So more or less Akeno will be pregnant after 11 years (10 years and 6 months more or less since only now is passed a whole year since the beginnin of the story) from now.