We present a study of electrodeposition of Ni nanocontacts in thin film and microwires gaps under an external applied magnetic field. The study is performed in comparison with electrodeposition of Cu that is not a magnetic material and therefore one can obtain conclusion from the electrodeposited structures on the effect of the magnetic field on the magnetic properties of the deposition. We show that indeed there is a magnetohydrodynamic effect. But we also show, what is more important, that the magnetic properties of the deposit are crucial for the deposited structure. In particular, for this case, the magnetoresistance plays a dominant role.