YOU SAID:
they had the baby for dinner
INTO JAPANESE
彼らは夕食に赤ちゃんを産んだ
BACK INTO ENGLISH
They gave birth to a baby for dinner
INTO JAPANESE
彼らは夕食のために赤ちゃんを出産しました
BACK INTO ENGLISH
They gave birth to a baby for dinner
That didn't even make that much sense in English.