I think for me, my birth fetish is contingent on a few things. It's the growing belly aspect of it, the anticipation of the child being born, the power that women possess to grow a human in their bodies, and then, not without struggle, the ability women have to push that child out into the world through a what seems to be, an impossibly small opening in their bodies.
It's all a foreign concept to me, as I have never been pregnant, and am still a few years off from having any children.
But I think it's natural to be curious what I'll look like when I finally decide to have children, and my body begins changing to accommodate a growing child within me.
I think that is part of what attracts me to enemas and the medfet world, because through them, as a fairly slender female, I can, temporarily, make myself appear a few months pregnant, simply by giving myself an enema.
The process helps satiate my curiosity about the future, and helps quell some of the fears I have about my body and how it will be affected by pregnancy (Will I be disgusted by my body as it grows? What will I look like with a small pregnant belly? What clothes of mine will look good on me when I am pregnant? Etc,) and the answers I have found, so far, have only encouraged me to want to have children, more so, than before I started experimenting.