The 'secret - keeping' trope is also quite common. Dean might be hesitant to tell others in the Supernatural world about his condition, fearing their reactions. And there's often the trope of the 'unexpected bond' that forms between them during this time, strengthening their relationship in ways they didn't expect, as seen in stories like 'The Unforeseen Bond' where they discover new aspects of their feelings for each other.
One common trope is the 'fish - out - of - water' situation for both characters. Castiel, being an angel, is not used to the concept of human pregnancy, and Dean has to deal with a very non - traditional male pregnancy. Another trope is the over - protective Castiel, like in many stories where he goes to great lengths to keep Dean safe during the pregnancy.
Many fanfictions use the trope of 'supernatural complications'. Since they are in the Supernatural universe, there could be other forces that either try to harm Dean because of the pregnancy or are interested in the unborn child for their own purposes. This adds an element of danger and adventure to the story, like in 'Perilous Pregnancy' where they have to fight off demons who want to use the baby for dark magic.
Chapter 487, "Found a Kindred Spirit?", is the clearest early answer because it turns Shang Shaojing's situation into a concrete plot event.
Chapter 348, "Seeing You Reminds Me of My Cousin", is the clearest early answer because it turns Luo's situation into a concrete plot event. Early on, Jiang Li's voice wasn't loud, but it carried enough power to.... By the end, Shanshui Pear Garden was a well-regarded Chinese restaurant in the....
Chapter 643, "Jiang Li Dominates the Trending Searches!", is the clearest early answer because it turns Jiang Li's situation into a concrete plot event. The chapter turns that into something concrete by moving from Qi Tianyu joyously carried his construction to the side to wait for...
Chapter 439, "Never Question Sister Li", is the clearest early answer because it turns Sister Li's situation into a concrete plot event. The chapter turns that into something concrete by moving from There was no helping it, she brought the man here, so even if he was...
Chapter 424, "He Must Be Very Strong", is the clearest early answer because it turns Tong Xiaoqi's situation into a concrete plot event. Early on, Shh!" Jiang Yan, who was leading the group, turned around and made a.... By the end, Isn't this just exploiting a loophole?!.
Chapter 406, "Barely Considered Living", is the clearest early answer because it turns Zheng Xun's situation into a concrete plot event.
Chapter 264, "The Truth", is the clearest early answer because the hidden truth stops feeling like mere subtext. A useful checkpoint is the way the scene starts with Jiang Li first reassured her mother, then opened the chat box with...
Chapter 441, "The Taoist also Chases Stars?", is the clearest early answer because it turns Fengshui Arrays's situation into a concrete plot event. The chapter gives readers a real answer by opening on She had also only learned a little trick after reading many books.
Chapter 149, "Director Zhang, I heard you've encountered some troubles lately", is the clearest early answer because it turns Zhang Cheng's situation into a concrete plot event.
Chapter 447, "Going Viral on the Internet", is the clearest early answer because it turns Going Viral's situation into a concrete plot event. The chapter turns that into something concrete by moving from Old Sir Jiang: "...." His face had grown even worse.