  We prove that Nahm transform for integrable connections with a finite number
of regular singularities and an irregular singularity of rank 1 on the Riemann
sphere is equivalent -- up to considering integrable connections as holonomic
$\D$-modules -- to minimal Laplace transform. We assume semi-simplicity and
resonance-freeness conditions, and we work in the framework of objects with a
parabolic structure. In particular, we describe the definition of the parabolic
version of Laplace transform due to C. Sabbah. The proof of the main result
relies on the study of a twisted de Rham complex.
