Check out all the disturbing pregnancy/birth/death imagery: the red water forming red stones within women's wombs; Wrath (created from Izumi's (the Elrics' substitute mother-figure) dead child) encased in Sloth (created from the Elrics' dead mother); Martel animating Al, then dying inside him; Scar's creation of the Philosopher's Stone in Al; Tucker (ew!) merging his daughter with a dog, then creating zombie!doll!Nina... I'm sure there's more.

Also, the remarkable wealth of mother figures: Trisha Elric, Izumi, Ross, Sloth, Rose... and their corresponding children and child figures.

Not so many father-figures, but the ones who are around are significant: Hughes, Tucker (ew!), and Hohenheim of Light.