The increased use of vitrified blastocysts has encouraged the development of various criteria for selecting the embryo most likely to implant. Post-thaw assessment methods and timetables vary among investigators. We investigated the predictive value of well-defined measurements of human blastocyst re-expansion, following a fixed incubation period. Post-thaw measurements were taken exactly at 0 and 120 ± 15 min. Minimum and maximum cross-sectional axes were measured. Three groups were defined: Group 1: embryos that continued to shrink by 10 µm or more; group 2: embryos that ranged from −9 to +9 µm; and group 3: re-expansion of 10 µm or more. Patient and morphokinetic data were collected and integrated into the analysis. A total of 115 cases were included. The clinical pregnancy rate for group 1 was 18.9%; group 2, 27%; and group 3, 51.2% (p = 0.007). Pre-thaw morphologic grading and morphokinetic scores of the study groups did not reveal differences. p-values were 0.17 for the pre-thaw morphologic score, 0.54 for KID3, and 0.37 for KID5. The patients’ demographic and clinical data were similar. The clinical pregnancy rate correlated with the degree of thawed blastocyst re-expansion measured 2 h after incubation. This standardized measure is suggested as a tool to predict the potential of treatment success before embryo transfer.

This multi-center study evaluated a novel microscope system capable of quantitative phase microscopy (QPM) for label-free sperm-cell selection for intracytoplasmic sperm injection (ICSI). Seventy-three patients were enrolled in four in vitro fertilization (IVF) units, where senior embryologists were asked to select 11 apparently normal and 11 overtly abnormal sperm cells, in accordance with current clinical practice, using a micromanipulator and 60× bright field microscopy. Following sperm selection and imaging via QPM, the individual sperm cell was chemically stained per World Health Organization (WHO) 2021 protocols and imaged via bright field microscopy for subsequent manual measurements by embryologists who were blinded to the QPM measurements. A comparison of the two modalities resulted in mean differences of 0.18 µm (CI −0.442–0.808 µm, 95%, STD—0.32 µm) for head length, −0.26 µm (CI −0.86–0.33 µm, 95%, STD—0.29 µm) for head width, 0.17 (CI −0.12–0.478, 95%, STD—0.15) for length–width ratio and 5.7 for acrosome–head area ratio (CI −12.81–24.33, 95%, STD—9.6). The repeatability of the measurements was significantly higher in the QPM modality. Surprisingly, only 19% of the subjectively pre-selected normal cells were found to be normal according to the WHO2021 criteria. The measurements of cells imaged stain-free through QPM were found to be in good agreement with the measurements performed on the reference method of stained cells imaged through bright field microscopy. QPM is non-toxic and non-invasive and can improve the clinical effectiveness of ICSI by choosing sperm cells that meet the strict criteria of the WHO2021.

This study evaluated the clinical outcomes associated with quantitative phase microscopy (QPM), an advanced 3D morphological sperm analysis technique using a virtual, stained model developed in our facility that indicates whether the inspected sperm should be selected for intracytoplasmic sperm injection (ICSI). We prospectively compared the clinical outcomes of three groups of cycles: (1) one with the QPM assessment, (2) one with conventional ICSI, without using QPM in the same patient, and (3) one with conventional ICSI cycles of an historical cohort of patients who did not undergo QPM. The outcomes of cycles using QPM vs. intracytoplasmic morphologically selected sperm injection (IMSI) cycles were also compared. A total of 1243 cycles were included. Pregnancy and delivery rates were higher among the QPM group compared to the standard ICSI group (56.2% vs. 18.1%, p = 0.04 and 50% vs. 9%, respectively, p = 0.02). Pregnancy and delivery rates were also higher among the QPM group compared to the IMSI group (56.2% vs. 16.6%, p = 0.01 and 50% vs. 16.6%, respectively, p = 0.03). No pregnancy complications were recorded in the QPM group. We conclude that QPM is a safe, non-invasive sperm selection technique for ICSI, with the potential to improve clinical pregnancy and delivery rates for couples with male infertility.