I've had a birth fetish for more than a decade, but never knew what it was. It wasn't until my teens that I discovered what a fetish was, and that helped. It's only been in the last two days that I've actively sought out others. I'm only just twenty three, so this has been a lifetime thing.
For me, it's not just the act of giving birth. I enjoy mpreg, egg laying, rapid/experimental/magical impregnation, no doctors, virgin birth as a consequence, and many others.
I once did a roleplay involving a forbidden relationship between two princesses, each betrothed to the other's brother. Unknown to them, they'd both had enchantments placed on them that if they had sex before they were wed, they would immediately fall pregnant with their lover's children as a way of catching the culprit. The amount of children they had was a result of the amount of orgasms they'd had.
The girls woke in the middle of the night as their bellies balloned with children and realizing what was happening they hid themselves away and after three days of constant growth went into labor. So while birthing their own babies, one had triplets and the other oversized twins, they were trying to assist each other and not let their families catch on.
It's a relief to find others who have similar tastes, and if you ever want to roleplay I have Skype, email and AIM.