Video guide for Physiological ICSI: PICSI� and Sperm Slow�, two ready-to-use systems designed for sperm-hyaluronic acid (HA) binding selection

Hyaluronic acid (HA) plays a fundamental role in sperm selection both in natural and in vitro fertilization. Only mature sperm which have completed their plasma membrane remodeling, the cytoplasmic extrusion and nuclear maturation have specific receptors to bind to HA in in vitro selection systems (1-3). It has been shown that the injection of spermatozoa bound to HA may improve the quality of the embryos and their development (4). This approach to ICSI with HA-bound sperm, when using HA-viscous medium (SpermSlowTM Origio, Denmark) or HA-culture dishes (PICSI® Sperm Selection Device -Origio), has been called “Physiologic ICSI” (4). It has been demonstrated that both these sperm selection systems are equally efficient (5, 6). A recent systematic review and meta-analysis (performed on 7 studies/1437 cycles) concluded that at the moment there is no firm clinical advantage in terms of pregnancy rate by using HA sperm selection technique (7). However, during ICSI, without the physiological check-points of natural fertilization, suboptimal spermatozoa may generate embryos, and subsequently babies. Although we have as yet real knowledge about human ICSI adults in the long term, by Physiologic ICSI is possible at very least to mimic nature in order to restore physiological selection and prevent hypothetical fertilization by DNA damaged and chromosomal unbalanced spermatozoa (6).