How do you say baby boy in Japanese?

There isn't one single perfect translation for "baby boy" in Japanese, as the best choice depends on context and level of formality. Here are a few options:

* 赤ちゃん (akachan): This is the most general term for "baby," and is gender-neutral. You could use this and add a clarifying phrase like 男の子 (otokonoko) meaning "boy" afterwards. So you'd say 赤ちゃん 男の子 (akachan otokonoko).

* 男の子の赤ちゃん (otokonoko no akachan): This literally translates to "boy's baby" and is a more precise way to say "baby boy".

* 男の赤ちゃん (otoko no akachan): Similar to the above, but slightly more concise, meaning "male baby".

* ベイビーボーイ (beibī bōi): This is a loanword directly from English and is often used in informal settings or on products.

For most situations, 赤ちゃん 男の子 (akachan otokonoko) or 男の子の赤ちゃん (otokonoko no akachan) would be perfectly acceptable and easily understood.