A standard karyotype typically takes 1–3 weeks, which is longer than many genetic blood tests because it isn’t a direct DNA readout – the lab has to actually grow your cells in culture first. Turnaround time depends on how quickly the cells divide (this varies person to person), how many rounds of culturing and staining are needed to get a clean, analyzable spread, and whether the finding is straightforward or needs extra review. A “delay” usually means the lab is being thorough, not that something is necessarily wrong.