To provide an obstetric monitor unit which is safe for a mother body and an embryo and correctly and reliably notify the initial stage of an obstetrics even from a remote place.

The obstetric monitor unit comprises: an electromagnetic induction oscillator 1 attached to one 31 of facing vulvae; and an electromagnetic induction receiver 2 attached to the other 32. The distance of an interval between the oscillator 1 and the receiver 2 is adjusted to be the distance for generating induced electromotive force in the normal states of both the vulvae 31, 32 and the distance by which the induced electromotive force cannot be generated in the opening states of both the vulvae 31, 32 in the case of an obstetrics sign.