Through the first two chapters, Akira would always get weird around the topic of pregnancy. When Ami talks about being inseminated, Akira gets up and walks out mid-coitus. When Ayane is laying the foundation to drop news of the pregnancy on him, he threatens to push her off the roof if she talks about being pregnant again.
It was so bad that I had suspected for quite some time that the real reason the loops are happening is because Maya had told him she was pregnant with his child, and he promptly jumped off the roof, and that's the leap that starts the game. Indeed, that was the core impetus behind the entire "Maya is pregnant" theory (that and the way she eats).
The only other reason I can think of for his reaction being so visceral is that maybe Sekai was pregnant when she died. Either way, something is definitely up with the way he has such a complex about pregnancy in the first half of the game (though that aspect of his personality definitely seems to have mellowed by chapter 4)
