nishizawa haruki

BACKGROUND: When using assisted reproductive technology, there are cases where, despite the transfer of a good embryo, sometimes pregnancy may not be the case. Thus, during hormone replacement cycle implantation, it is important to synchronize the number of days of progesterone administration with the degree of embryo maturity. This study aimed to compare the outcomes of the administration of oral dydrogesterone for the duration of progestin use during the hormone replacement cycle for frozen-thawed blastocyst transfer. MATERIAL AND METHODS: The primary outcome of this study was the clinical pregnancy rate. We performed a retrospective cohort study of patients who underwent frozen-thawed blastocyst transfers between January 2017 and December 2024. According to our standard protocol, a vitrified-warmed blastocyst transfer was performed using dydrogesterone, which was administered orally at our center. A total of 554 cases were included in the study. Using the Gardner classification to evaluate the quality of blastocysts, grade AA was classified as the best quality, the AB/BA group as good quality, and the BB group as fair quality. We classified the 554 cases into 317 AA, 163 AB/BA, and 74 BB cases using the Gardner classification. Based on the duration of progestin administration, patients were divided into four groups: 120 hours (120 h), 132 hours (132 h), 144 hours (144 h), and 156 hours (156 h). We used the Shapiro-Wilk method and the Steel-Dwass test to determine whether there were differences in patients' background age and BMI among the four groups (120 h, 132 h, 144 h, and 156 h). We used Fisher's exact test and the Bonferroni method to determine whether there were differences in the final outcome of pregnancy rate between the four groups of 120 h, 132 h, 144 h, and 156 h. RESULTS: In the analysis of all embryos, the pregnancy rate at each timepoint of the primary evaluation was significantly higher in the 144-h group than in the 132-h group. Next, on analyzing the results by embryo grade, there was no difference in the pregnancy rate at each timepoint in the AA group. In the AB/BA group, the pregnancy rate was higher in the 144-h group than in the 132-h group. In the BB group, the pregnancy rate was higher in the 144-h group than in the 132-h group. CONCLUSION: This study clarified two aspects. First, the pregnancy rate in the 144-h group was significantly higher than that in the 132-h group in the analysis of all embryos. Second, the window of implantation may be more important for poor-quality embryos. This study showed that the oral administration of dydrogesterone requires a window of implantation of at least 144 hours.

Cytogenetic information about the product of conception (POC) is important to determine the presence of recurrent chromosomal abnormalities that are an indication for preimplantation genetic testing for aneuploidy or structural rearrangements. Although microscopic examination by G-staining has long been used for such an evaluation, detection failures are relatively common with this method, due to cell-culture-related issues. The utility of low-coverage whole-genome sequencing (lcWGS) using short-read next-generation sequencing (NGS) has been highlighted recently as an alternative cytogenomic approach for POC analysis. We, here, performed comparative analysis of two NGS-based protocols for this purpose based on different short-read sequencers (the Illumina VeriSeq system using a MiSeq sequencer and the Thermo Fisher ReproSeq system using an Ion S5 sequencer). The cytogenomic diagnosis obtained with each NGS method was equivalent in each of 20 POC samples analyzed. Notably, X chromosome sequence reads were reduced in some female samples with both systems. The possibility of low-level mosaicism for monosomy X as an explanation for this was excluded by FISH analysis. Additional data from samples with various degrees of X chromosome aneuploidy suggested that it was a technical artifact related to X chromosome inactivation. Indeed, subsequent nanopore sequencing indicated that the DNA in the samples showing the artifact was predominantly unmethylated. Our current findings indicate that although X chromosome data must be interpreted with caution, both the systems we tested for NGS-based lcWGS are useful alternatives for the karyotyping of POC samples.

INTRODUCTION: The da Vinci SP surgical system is a surgical platform capable of implementing robotic-assisted surgery through a single port and was first introduced in Japan at our hospital. In this paper, we describe our experience of the initial introduction of the da Vinci SP surgical system and its surgical outcomes. This is the first report on the surgical outcomes of using da Vinci SP, and its comparison with the conventional system in Japan. METHODS: After developing an application for a highly difficult new medical technology in-house, we compared the surgical outcomes (median values) of 15 patients who had undergone total hysterectomy at our hospital using the da Vinci SP (1-port) system (SP group) for uterine myoma after March 2023 and of 154 patients who underwent total hysterectomy using the conventional da Vinci Xi (four ports) system (Xi group) for uteri weighing <500 g. RESULTS: The results of the comparison of the characteristics between 15 patients in the SP group and 154 patients in the Xi group were as follows: uterus weight (g): 230 (90-500) versus 222 (55-496) (p = .35); surgical time (minutes): 199 (171-251) versus 198 (88-387) (p = .63); intraoperative blood loss (mL): 13 (5-82) versus 20 (2-384) (p = .17); and rate of surgical complication (%): 0.0 versus 1.3 (p = .66). The data indicated a comparable weight of the resected uterus, surgical time, intraoperative blood loss, and rate of surgical complications between the two groups. CONCLUSION: Robotic-assisted total hysterectomy using the da Vinci SP surgical system allowed clinicians to safely perform surgeries according to the conventional systems.