Perhaps Darien is pressured by external factors like his family or society. His family might not approve of Serene, or society's expectations are weighing him down. As a result, he makes the wrong choice of leaving Serene, who is now pregnant and has to face the situation alone.
There could also be other secondary characters. Maybe Serene has a best friend who tries to support her through this difficult time after Darien leaves. Or perhaps Darien has a confidant who either encourages or tries to stop him from leaving Serene.
Well, one possible plot could be Serena struggling to come to terms with being pregnant alone after Darien leaves. She might have to face the judgment of society and her own self - doubt. She could then decide to be strong for the baby and start building a new life for herself, proving that she doesn't need Darien to raise the child.
Well, one possible plot could be that Lucy has to face the challenges of pregnancy alone after Natsu leaves. She might struggle with financial difficulties and the emotional turmoil of raising a child without the father. She could then find support in her friends in the guild, who help her through the tough times and she eventually becomes a strong, independent mother.
One possible plot could be Marinette struggling to raise the baby on her own while dealing with the heartbreak of Adrien leaving. She might find support from her friends like Alya, who helps her through the tough times. Meanwhile, Adrien could be off on some self - discovery journey and later realizes his mistake.
One possible plot could be that Rose has to face the challenges of single motherhood. She might struggle with financial difficulties while also dealing with the emotional turmoil of Dimitri leaving. Maybe she'll find support from unexpected friends or family members and strive to build a good life for herself and the baby.
Well, it could be that Bella decides to raise the baby on her own without Paul. She could focus on building a support network of friends and family. Another aspect could be that the werewolf or vampire community (depending on the context of the original story) has some sort of reaction to Bella's situation. For example, they might try to protect her from any threats that come her way because of the unborn child.
Perhaps Naruto leaves because he wants his child to grow up away from the pressures and expectations that come with being in Konoha. He might feel that the outside world can offer a more peaceful and normal upbringing for his family.
Serena would likely become more independent. Since Darien has left her while she's pregnant, she has no choice but to rely on herself. She might become more assertive in making decisions for herself and her unborn child.
One possible plot could be that Harry Potter discovers he is pregnant (through some magical means perhaps) and decides to leave England because he wants to protect his unborn child from the dark forces that still lurk in the country. He might go to a far - off magical land where he can raise the child in peace and secrecy.
Perhaps Caroline initially struggles with the idea of being a single mother. She may consider reaching out to Klaus but then decides against it. As time passes, she discovers new powers within herself because of the pregnancy. These powers help her protect her unborn child from various threats that come her way, and she becomes a stronger and more independent character.