  We analize the stability of a class of thin-shell wormholes with spherical
symmetry evolving in flat FRW spacetimes. The wormholes considered here are
supported at the throat by a perfect fluid with equation of state
$\mathcal{P}=w\sigma$ and have a physical radius equal to $aR$, where $a$ is a
time-dependent function describing the dynamics of the throat and $R$ is the
background scale factor. The study of wormhole stability is done by means of
the stability analysis of dynamic systems.
