  Let $X$ and $Y$ be compact K\"ahler manifolds of dimension $3$. A
bimeromorphic map $f:X\rightarrow Y$ is pseudo-isomorphic if
$f:X-I(f)\rightarrow Y-I(f^{-1})$ is an isomorphism.
  Let $T=T^+-T^-$ be a current on $Y$, where $T^{\pm}$ are positive closed
$(1,1)$ currents which are smooth outside a finite number of points. We assume
that the following condition is satisfied:
  {\bf Condition 1.} For every curve $C$ in $I(f^{-1})$, then in cohomology
$\{T\}.\{C\}=0$.
  Then, we define a natural push-forward $f_*(\varphi dd^cu\wedge f^*(T))$ for
a quasi-psh function $u$ and a smooth function $\varphi$ on $Y$. We show that
this pushforward satisfies a Bedford-Taylor's monotone convergence type.
  Assume moreover that the following two conditions are satisfied
  {\bf Condition 2.} The signed measure $T\wedge T\wedge T$ has no mass on
$I(f^{-1})$.
  {\bf Condition 3.} For every curve $C$ in $I(f^{-1})$, the measure $T\wedge
[C]$ has no Dirac mass.
  Then, we define a Monge-Ampere operator $MA(f^*(T))=f^*(T)\wedge f^*(T)\wedge
f^*(T)$ for $f^*(T)$. We show that this Monge-Ampere operator satisfies several
continuous properties, including a Bedford-Taylor's monotone convergence type
when $T$ is positive. The measures $MA(f^*(T))$ are in general quite singular.
Also, note that it may be not possible to define $f^*(T^{\pm})\wedge
f^*(T^{\pm})\wedge f^*(T^{\pm})$.
