Daniela Guidetti

The aim of our study was to provide a retrospective single-center experience of the additional workload associated with routine PGT, including embryologist training and suggested staffing levels. A total of 4945 IVF cycles were retrospectively considered, of which 1680 were PGT cycles with a total of 5258 biopsied blastocysts. An exponential increase in the proportion of PGTs over OPUs was observed, from 0.2% in 2015 to 72.9% in 2024. The number of viable embryos for biopsy was significantly increased by the systematic adoption of an extended embryo culture and the concomitant transition from a day 2 Double Embryo Transfer (DET) to a day 5 Single Blastocyst Transfer (SET) policy in 2020. In order to cope with the increasing workload, a concomitant increase in the number of embryologists involved in blastocyst biopsy was adopted, with a second embryologist in 2020, a third in 2021, and a fourth in 2022, with a trend comparable to that observed for the proportion of PGT cycles over IVF cycles performed during the study period. The appropriate number of staff required for the IVF laboratory was calculated using the Staffing Model for ART (smART) calculator, based on 12 routine IVF procedures. An optimal balance between operational procedures and staffing levels was achieved when the difference (Δ) was ≤10%, ensuring the efficient maintenance of PGT in the IVF laboratory.

This study compared the DuoStim protocol with two conventional follicular phase stimulations for vitrified oocyte accumulation in poor-prognosis patients undergoing PGT-A. A retrospective analysis of 112 IVF cycles was conducted, with 66 cycles among patients undergoing DuoStim (DS-Group) and 46 among patients undergoing conventional follicular phase stimulations (DF-Group). The primary outcome was the time to live birth, while secondary outcomes included clinical pregnancy rate, miscarriage rate, live birth rate, and cumulative live birth rate. The final analysis included 66 patients in the DS-Group and 40 in the DF-Group, as 6 women (13%) in the DF-Group discontinued treatment after the first stimulation. Oocyte yield was similar between groups (8.4 ± 3.9 in DS-Group vs. 8.2 ± 4.0 in DF-Group, p = 0.80), as was the number of euploid blastocysts (0.9 ± 1.2 vs. 1.1 ± 1.1, p = 0.37). The cumulative live birth rate was 22.7% in the DS-Group and 25% in the DF-Group (multivariate odds ratio adjusted for maternal age and male factor: 1.05, p = 0.93). The time to live birth was significantly shorter in the DS-Group (81.5 ± 15.5 days) compared to the DF-Group (153.7 ± 78.2 days, p < 0.001). DuoStim showed similar efficacy but a shorter time to live birth.

The association of recombinant FSH (rFSH) plus recombinant LH (rLH) is currently used for Controlled Ovarian Stimulation (COS) in human IVF, but its efficacy has, to date, not yet been compared to that of human Menopausal Gonadotropin (hMG), the FSH + LH activity-containing urinary drug. Eight hundred forty-eight (848) IVF patients classified as expected “poor” or “normal” responders according to antral follicle count (AFC) and basal (day 3) FSH were treated with rFSH + rLH (2:1 ratio, n = 398, Group A) or hMG (n = 450, Group B). Data were collected under real-life practice circumstances and the pregnancy rate with fresh embryos was calculated by stratifying patients according to the number of retrieved oocytes (1–2, 3–4, 5–6, 7–8, >8). Overall, the pregnancy rate in both groups progressively improved according to the number of oocytes retrieved. When comparing patients within the same subgroup of oocyte yield, Group A and B showed a comparable outcome up to the reported highest yield (>8). When more than 8 oocytes were available, Group A had a significantly better pregnancy rate outcome. Patients’ characteristics did not significantly differ between the two groups and the better outcome in the best responding patients in Group A was confirmed by a multivariable logistic regression analysis, that showed that both the use of rFSH + rLH and the total number of retrieved oocytes increased the probability of pregnancy with odd ratio (OR) of 1.628 and 1.083, respectively. When comparing patients with the same number of retrieved oocytes under real-life circumstances, the association of rFSH + rLH results in a significantly higher pregnancy rate than hMG when more than 8 oocytes are retrieved. The reason(s) for this are unknown, but a more favorable effect on oocyte quality and/or endometrial receptivity could be involved.