Assisted reproductive techniques (ARTs) has been defined as procedures that involve in vitro manipulation of oocytes, semen and embryos with the aim of establishing a pregnancy. In equine species, the use of these techniques is relatively recent compared to other domestic species, such as cattle and pigs [1]. These techniques include ovarian stimulation, semen collection and preservation, in vitro fertilization, intracytoplasmic sperm injection, embryo preservation and transfer, and cloning procedures, which can induce significant modifications in gametes [2,3] and in embryonic microenvironment [[4], [5], [6]]. The early stages of embryo development are known to be strongly affected by environmental conditions, with long-term effects on fetus, newborn foal and adult health [[7], [8], [9]]. It is therefore essential to evaluate whether the use of ARTs in equine species could affect pregnancy, fetal membranes and umbilical cord, the onset of dystocia and the health of mare and foals as extensively reported in bovine and ovine [[10], [11], [12], [13], [14], [15]].

Although it is known that pregnancies produced by somatic cell nuclear transfer (SCNT) in the mare could present fetal membranes alterations, umbilical cord abnormalities, hydroamnios, hydroallantois, abortion, maladjustment, enlarged umbilical remnant, and angular deformity of the forelimbs [[16], [17], [18], [19], [20], [21]], only few studies have focused on the potential of postnatal consequences of ARTs [[22], [23], [24]].

The aim of this study was to retrospectively evaluate whether the transfer of in vivo or in vitro produced embryos may be associated with the presence of macroscopic alterations of fetal membranes and umbilical cord and whether the use of these techniques could influence pregnancy and the neonatal outcome.