Found: Young Vampire Investigates Disappearances

I think this is the first or second book in an urban fantasy triology I read in the late 2000's to early 2010's. Iron may have been part of the title or of another book in the trilogy. I think it is based in the Eastern US.

The main character was a male vampire, I believe in his early 20's. The author's world building had a non-traditional vampire origin method, a sire would give blood to two humans, the humans would have a child, the child would be the new vampire, recieving full vampire powers upon the death of the human parents. Unusually, MC's "parents" were still being kept alive by his sire, to the displeasure of his more traditional siblings. As still mostly human the main character tries to stay seperated from the supernatural side of the world.

He gets roped into investigating some disappearances, I think by his "human" roommate vanishing. He teams up with a kitsune woman, traces the disappearences to adults whose parents had gone to a suspicious "100% success rate" fertility clinic. Turns out all the babies from the clinic are changlings, the fae consider them their people and if they use a few later on in life for experiments or sacrifices then *shrug* no biggie. They had been magically trying to increase the percentage of fae blood in hybrid offspring since there are very few full blooded fae left. Big fight scene, vampire power up, I think there is a fire...

By the end of the third book MC is a full blooded Vampire and the Kitsune is his girlfriend, his sire dies and he takes power from his siblings by uniting the other supernatural creatures in the area over the period of the trilogy. Power in numbers, democracy, all that jazz.

I found it! Of course, as soon as I ask for help! The Generation V series by M/L Brennan, the second book is Iron Night so I think it is that one.