YOU SAID:
I will have a baby in 10 years.
INTO JAPANESE
私は10年後に赤ちゃんを産みます。
BACK INTO ENGLISH
I have a baby 10 years later.
INTO JAPANESE
私は10年後に赤ちゃんをもうけています。
BACK INTO ENGLISH
I have a baby 10 years later.
That didn't even make that much sense in English.