Greetings, friends!
First of all, let me state in advance that the following is my own opinion, why I only offer as explanation.
Second of all, I mean no disrespect toward any person or fetish. To each his/her own.
The way I see it, a caption theme consists of "major" elements, "minor" elements and "fluff".
The major elements are those that can be considered turn-ons or turn-offs to the exclusion of almost everything else. Often, people will not even look at the caption if it's major theme is one they are not comfortable with. You will often find such themes in the "dislike" portion of people's preferences.
Some examples include: age regression (young), age progression (mature), homosexual/lesbian relationship, heterosexual relationship, BBW, humiliation, turned into object, and -- yes -- pregnancy.
The minor elements affect the enjoyment the viewer gets form the caption but will usually not "make or break" it.
Examples may include race, body shape variations, transformation trigger, setting, etc.
Then, there's fluff like: color of clothes, objects present in the picture, dates or events, names, physical locations.
Of course, it is more like a smooth gradient than a strict categorization. Things like hair color will be considered fluff by some, minor by others and possibly major by a select few. However, I claim that the general idea is sound.
So far, the contests were firmly into fluff-to-minor territory and, in my humble opinion, for good reason. Consider, for the sake of an example, a contest theme of, say, BBW. While a popular fetish in and of itself, I trust that a significant portion of the members do not find grossly overweight bodies very appealing and therefore will not participate in any capacity: will not submit entries, will not view the submitted entries, will not vote and will not leave comments. That would basically go against the whole idea of having a public contest in the first place.
That is the reason that I believe that a pregnancy theme is not advised. The fact that I am personally uncomfortable with it is irrelevant, as I would apply the same arguments to a "lesbian" theme, which happens to be my personal favorite.
Now, considering the Joss Whedon theme, I actually find it quite inclusive. Obvious themes would include: supernatural (vampires, demons, were-creatures, witches), science fiction, body swap / memory download and mutations / super-powers. However, there is no need to limit yourself to the themes of his more known works. For example, he was also involved in "Roseanne", "Parenthood" and "The Office" series.
That said, if you strongly feel that pregnancy is a good contest theme, by all means make a poll and vote on it.
Peace,
Lurker.
