One plot idea could be Addison dealing with the challenges of her pregnancy while also trying to balance her career. Maybe she has to make tough decisions between taking time off and continuing her work. Another could be the reactions of her friends and family to the pregnancy. Some might be overjoyed, while others could be worried about how it will change her life.
One potential love interest could be an old flame who re - enters her life. He could be there to support her during the pregnancy, and they could rekindle their relationship. Maybe he's changed for the better and is now more ready for a committed relationship with Addison and her unborn child.
One common theme is love triangles. Given their complex relationship in the original show, fanfics often explore different outcomes of the love triangle between Addison, Derek, and other characters. Another theme is redemption. Addison might be written as trying to redeem herself in Derek's eyes or in the eyes of others.
Well, it's hard to say who the 'best' is as it depends on personal taste. But some popular authors in the fanfiction community might be those who really capture the essence of Addison and Derek's complex relationship. For example, some authors who are good at writing detailed emotional scenes between them.
One popular Addison pregnant fanfiction could be where it explores her journey through pregnancy with a lot of emotional turmoil. It might focus on how she deals with the changes in her body and her relationships. For example, in some fanfictions, she might struggle with her career while being pregnant.
You can start by looking on fanfiction platforms like Archive of Our Own (AO3). It has a large collection of fanfics. Just type in 'Addison Montgomery Derek Shepherd' in the search bar, and you'll get a plethora of stories. Another option is Fanfiction.net, though the quality may vary more there.
One interesting plotline could be them getting a second chance at love. Maybe after years apart, they meet in a different city and rediscover their feelings for each other. Another could be a plot where they have to work together on a very difficult medical case that brings them closer.
Another theme is the relationship changes. Her relationship with the baby's father might be explored, whether it's a new relationship or an existing one. There could also be changes in her friendships as she focuses more on her upcoming motherhood.
The relationship could also develop in a more platonic way. They could be like sisters, supporting each other during doctor's appointments and prenatal classes. They might have arguments along the way, but always come back to support each other because they know how tough pregnancy can be.
One aspect that might be explored in such fanfiction is Addison's medical decisions during her pregnancy. Since she is a doctor herself, it would be interesting to see how she balances her own health and the health of her unborn child while still being involved in the complex cases at the private practice.