Software based analysis of local zona pellucida thickness variation: bending energy as a predictive window on day 2 embryo fate.

2)Objective of the present retrospective observational study is to evaluate the clinical effectiveness of “Embryon”,a new proposed software program based on the semiautomatic Local Zona Pellucida Thickness Variation (LZPTV) computation of Day 2 Intracytoplasmatic Sperm Injection (ICSI) embryos images to provide a reliable additional information regarding embryo fate. 3)LZPTV of day 2 ICSI embryos appears, after preliminary observations, able to provide a significant information as integrative standardized approach for Assisted Reproduction Technologies (ART) practice and research. 4)Zona Pellucida Thickness (ZPT) and ZPTV seem to successfully predict the clinical outcome of ART. A number of morphological, morphokinetics, automated and semi-automated non-invasive methodologies for the assessment of various human embryo stages has been developed to evaluate the feasibility of a human embryo to implant in a woman uterus but, up to date, none has been proven superior to the others. 5)400 embryo digitalized images from 150 ICSI patients observed at ART Unit “Sapienza” University of Rome, Italy, during October 2011-October 2012 were blindly retrospectively analyzed using “Embryon” software program (# IT RM2012A00025, Advanced Computer Systems ACS- Rome, Italy). It characterized the LZPTV of an embryo by a single numerical value. 6)The a-dimensional final value obtained by “Embryon” captures the high frequency variability of ZPT curve (Normalized Bending Energy), to evaluate the hypothesis that embryos with high LZPTV value (Top) have higher implantation capacities, thus higher probability to proceed to term (life birth) compared to embryos with lower score (Poor). 7)According to LZPTV absolute values, the 157 patients, with similar clinical and biological parameter were split in “Top” and “Poor” clusters: “Top” (Group A: 54 patients) if at least on “Top” embryo was present; “Poor” (Group B: 103 patients) if the previous condition is not verified. “Top” patients presented significantly higher birth rate (54.7%) compared to “Poor” patients (9.7%)(p<0.05). 8)If prospectively confirmed in a larger series of patients, possibly with single embryo transfer, for its robustness and total reproducibility, LZPTV may represent an integrative tool to distinguish embryos able to proceed to term. Factors not related to the embryo quality cannot be underestimated. 9)The proposed method is based on the computation of a “form factor”, rather than to its macroscopic characteristics. Similar methods (e.g. ZPTV) are focusing only on high-level average ZP value of the shape, whereas our approach analyzes a granular set of shape factors in proximity of the ZP border.