  We derive a thermodynamic uncertainty relation for first passage processes in
quantum Markov chains. We consider first passage processes that stop after a
fixed number of jumps, which contrasts with typical quantum Markov chains which
end at a fixed time. We obtain bounds for the observables of the first passage
processes in quantum Markov chains by the Loschmidt echo, which quantifies the
extent of irreversibility in quantum many-body systems. Considering a
particular case, we show that the lower bound corresponds to the quantum Fisher
information, which plays a fundamental role in uncertainty relations in quantum
systems. Moreover, considering classical dynamics, our bound reduces to a
thermodynamic uncertainty relation for classical first passage processes.
