Board Thread:Wiki Discussions/@comment-24772621-20140501232434/@comment-24874466-20140505042536

There isn't much info on the topic, but I think not many people probably knew Kushina & Minato were even together, much less having a baby. Kushina was the Jinchuuriki of the kyuubi and her seal would weaken of the period of her pregnancy. Hiruzen knew this, and others probably did too. Hiruzen most-likely dubbed her pregnancy secret because problems may arise from people finding out the Kyuubi's seal would weaken during the pregnancy period. Mikoto new about Kushina's pregnancy because they were friends, but I don't think she knew about the Kyuubi. No one probably did. After Minato and Kushina's deaths, people who new about the pregnancy were probablt told Kushina died giving birth or something and they couldn't save the baby. I'm guessing everyone in the village was told Naruto was just some random orphan. No one bothered to question this because everyone saw him as the demon-fox. I too wonder why no one recognized his last name though. There's no way Mikoto would not have known her best friend's last name (Or maiden name) or the last name of the "Demon-Fox Boy".