One common theme could be family support. When a character is pregnant, the other Simpsons family members might come together to support her. Another theme could be the anticipation and excitement of a new addition to the family.
A common theme is family unity. As mentioned before, the family often comes together to support Marge during her pregnancy. Another theme could be anticipation. Everyone in the family and the town might be anticipating the new arrival with different emotions.
Growth and change is also a positive theme. The pregnancy can be a catalyst for other characters to grow. For example, Bart might become more responsible, realizing he'll soon be an older brother. He could start to do better in school and be more helpful at home, which is a positive development for his character.
One possible storyline could be Marge getting pregnant again and the family's chaotic yet heartwarming preparation for the new baby. For example, Homer might try his best to fix up the baby's room but end up making a mess. Another could be Lisa imagining what it would be like to have a younger sibling and writing in her diary about her hopes and fears.
One common theme is friendship. Often, the male OC will form strong friendships with the existing Simpson family members or other Springfield residents. Another theme is adventure. They might embark on wild adventures around Springfield or even outside of the town. For example, going on a road trip with the Simpsons.
One common theme is friendship. Despite their differences, Homer and Ned often form an unlikely friendship in fanfiction. For example, they might bond over a shared hobby like gardening in some stories.
One common theme is the contrast between their personalities. Lisa is smart and kind - hearted, while Nelson is more of a bully. Writers often explore how they bridge this gap.
One common theme is the clash of cultures. The Simpsons are from a modern - day, somewhat comical American family setting, while Naruto is in a feudal - like Japanese ninja world. So, stories often explore how these two very different cultures interact.
One major theme is cultural exchange. The ninja culture from Naruto and the American suburban culture of the Simpsons are very different. In fanfics, they often explore how characters from one world react to the traditions and values of the other. For example, how the Simpsons would view the ninja code of honor. Also, the theme of family is important. Both Naruto, who grew up without his parents, and the Simpson family, with their complex family dynamics, can have some really touching interactions when brought together in fanfics. There could be stories where Naruto finds a new kind of family with the Simpsons, or vice versa.
One common theme could be the struggle with family reactions. In such fanfictions, the 14 - year - old character who is pregnant might face disappointment or anger from her parents. Another theme could be the social ostracism she experiences at school. Her peers might treat her differently, which adds to her emotional turmoil.
I'm not really into that specific type of fanfiction myself, but you could try searching on fanfiction websites like FanFiction.net or Archive of Our Own. Just type in 'The Simpsons pregnant' in their search bars and see what comes up.