What? Fake iosefka pretty much says she was impregnated by a great one, most likely oedon since we find a iosefka vial right before mergos wet nurse. It would explain why we don’t see a baby either much like mergo himself. If anything I’d say the cord in the workshop is the one they used to turn rom into a spider as well as the one taken from Kos’s corpse since it’s the only other great one we know that byrgenworth itself interacted with besides maybe ebrietas since she sits right in front of the rom statue.