Perhaps the fanfiction could revolve around the challenges during the birth. There could be some complications, but through the love and support of the family and the skills of the medical staff, baby Shikadai is born safely. It could also show how the community around them comes together to support the new family during this time.
Obviously, Shikadai's parents would be central characters. His mother would be going through the process of pregnancy and childbirth, and his father would be there for support. Also, the medical staff or midwives in their world would be involved, taking care of the mother and baby during the birth.
In a fanfiction about baby Naruto's birth, a really interesting aspect could be the secrets that were passed down during that time. For example, if there were any special Uzumaki clan traditions related to the birth of a new heir. And what if some of the older ninja in the village, who knew about the Uzumaki clan's power, were already making plans for Naruto's future? Maybe they were thinking about how to train him to be a great asset to the village from the very start.
One idea could be that they go on a mission together in a mysterious forest. Along the way, they face various challenges that test their skills and teamwork. This could lead to a deeper understanding and connection between them.
Another idea is that Shikadai travels to a future time where Konoha has faced a great disaster. He then has to figure out how to use his knowledge from his original time to reverse the situation. Maybe he discovers new forms of chakra or ninja tools in this future Konoha that he can bring back to his own time to improve the village's defenses.
One possible storyline could be that Shikadai is on a mission and gets caught in an unexpected ambush by a group of powerful enemies. He might be outnumbered and sustain injuries while trying to fight them off and protect his comrades. Another could be that he's involved in a training accident that goes horribly wrong, like a jutsu backfiring on him and causing him physical harm.
One possible plot could be that Shikadai is kidnapped by a group of rogue ninjas who want to use his intelligence for their own evil plans. His friends then embark on a mission to rescue him, facing various challenges along the way.
One interesting plot could be baby Naruto and baby Sasuke getting lost in the forest together. They have to rely on their budding instincts and nascent chakra to find their way back. Maybe they encounter some small, friendly forest creatures that help them. Another idea is that they accidentally switch places in the village for a day. This leads to chaos as the villagers react differently to them being in the wrong 'homes'.
Another plotline could be that during the birth, Katniss has flashbacks of her time in the Hunger Games. These memories fuel her determination to create a better world for her child. The baby's arrival also causes a shift in the political situation, as the districts see the new life as a sign that they need to work even harder to ensure a safe and prosperous future for all children.
One popular 'baby Shikadai and Shikamaru fanfic' could be 'A Father's Bond'. It beautifully depicts Shikamaru's journey in fatherhood with baby Shikadai, showing his growth from a laid - back guy to a responsible dad. Another might be 'Shikadai's Early Days' which focuses on the cute and funny moments of baby Shikadai and how Shikamaru tries to handle them.
One idea could be exploring the emotions of Hinata during the birth. Maybe she's worried about Boruto's future in a world filled with challenges. Another could be how Naruto, as a new father, is torn between his duties as Hokage and being there for his family. For example, he might have to leave Hinata's side during the birth to deal with a sudden threat to the village, and then rush back to be with his new - born son.