The impact of a second embryo biopsy for preimplantation genetic testing for monogenic diseases (PGT-M) with inconclusive results on pregnancy potential: results from a matched case-control study.

PURPOSE: To evaluate whether a second biopsy, following a first diagnostic failure on blastocysts tested for preimplantation genetic testing for monogenic diseases (PGT-M), allows to obtain genetic diagnosis and to what extent this procedure can influence clinical pregnancy and live birth rates compared to the PGT-M process with a successful genetic diagnosis from the first biopsy. METHODS: Embryos from women who underwent PGT-M in an infertility centre and who had been transferred after two biopsies for genetic analysis (n = 27) were matched in a 1:1 ratio accordingly to women's age (± 1 year) and fertility status (fertile vs infertile), as well as with the study period, with embryos who were transferred after receiving a conclusive PGT result straight after the first biopsy (n = 27). The main evaluated outcome was clinical pregnancy rate following embryo transfers in which healthy embryos were transferred after only one biopsy and those in which an embryo was transferred after being re-biopsied. Live birth rate was the secondary outcome. RESULTS: Clinical pregnancy rate was 52% (95% CI: 34-69) following the transfer of a single-biopsy blastocyst and 30% (95% CI: 16-48) following the transfer of a re-biopsied blastocyst. The likelihood to have a healthy baby was 33% (95% CI: 19-52) following the transfer of a blastocyst biopsied once and 22% (95% CI: 11-41) following the transfer of a re-biopsied blastocyst. CONCLUSIONS: The re-biopsy intervention seems to considerably reduce the pregnancy potential of a blastocyst. However, a greater sample size is necessary to clarify this issue definitively.

Conventional IVF performs similarly in women with and without endometriosis.

PURPOSE: A reduced oocyte competence has been claimed as one of the factors underlying infertility in women with endometriosis. This idea has justified the hypothesis that intracytoplasmic sperm injection (ICSI), rather than conventional IVF (c-IVF), may overcome oocyte impairment and ensure better assisted reproduction technology (ART) outcomes; however, data from the literature are controversial. Thus, the aim of this study was to compare ART success rates following (c-IVF) between women with and without endometriosis in the presence of normozoospermic partners. METHODS: This is a retrospective, matched case-control study of 314 patients who underwent c-IVF cycles between January 2014 and December 2020. Women with endometriosis were matched in a 1:1 ratio with patients undergoing ART for other indications, considering age (± 6 months), number of oocytes retrieved (± 1), and study period. The main outcome measures included total fertilization failure, fertilization rate, embryo quality, cumulative clinical pregnancy, and live birth rates. RESULTS: The fertilization rate and the proportion of women with total fertilization failure did not differ between women with and without endometriosis. Similarly, all other embryological variables did not also differ, except for the number of top-quality cleavage stage embryos which was higher in the endometriosis group. Cumulative clinical pregnancy and live birth rates were similar between women with and without endometriosis. CONCLUSION: A diagnosis of endometriosis does not negatively affect the performance of c-IVF; thus, c-IVF can be efficiently used in women affected, unless a male factor is also involved. This issue holds clinical relevance to help operators on their insemination technique decision-making.

Follicular steroidogenesis in random start protocols for oocyte cryopreservation.

PURPOSE: Random start protocols are commonly used for oocyte cryopreservation in women with cancer. However, albeit generally reassuring, available evidence is still insufficient to rule out a sub-optimal cycle outcome. This study aimed to compare follicular steroidogenesis between women initiating the random start protocol in the luteal phase and those initiating in the follicular phase. METHODS: Consecutive women with cancer scheduled for oocyte cryostorage were prospectively recruited. We excluded those requiring a concomitant letrozole assumption. All women received a standardized protocol with recombinant FSH and GnRH antagonists. At the time of oocyte retrieval, follicular fluids were pooled, and a sample was collected and frozen at -80 °C. All samples were assayed concomitantly after thawing by liquid chromatography-tandem mass spectrometry. The concentration of 15 different steroid hormones was determined. RESULTS: Seventy-one women were recruited. Thirty-three initiated the ovarian stimulation in the luteal phase, while the remaining 38 initiated in the follicular phase. Baseline characteristics were generally similar. Cycle outcome did also not differ; the median (interquartile range) number of frozen mature oocytes was 9 (5-14) and 10 (5-21), respectively (p = 0.42). None of the 15 tested steroid hormones differed. CONCLUSIONS: The endocrine microenvironment surrounding oocytes is not markedly influenced by the phase of the menstrual cycle at the initiation of ovarian stimulation. This result further supports the validity of random start protocols.

Effect of letrozole on follicular fluid steroids concentrations in cancer patients undergoing oocyte cryopreservation.

PURPOSE: To investigate the impact of letrozole administration on follicular steroid hormones during controlled ovarian hyperstimulation for fertility preservation. METHODS: One hundred and nineteen women with cancer undergoing oocytes retrieval for fertility preservation were recruited. All women underwent ovarian hyperstimulation according to a random start protocol. Those with hormone-sensitive tumors also received letrozole, an aromatase inhibitor aimed at keeping peripheral estrogen levels low. At the time of oocytes retrieval, a sample of follicular fluid was collected and frozen. All samples were assayed concomitantly after thawing, by liquid chromatography tandem mass spectrometry. The concentration of 15 steroid hormones was determined and results were compared between women who did and did not receive letrozole. RESULTS: Fifty-two women were treated with letrozole, while 67 were not. Statistically significant differences emerged for 12 of the 15 tested steroids. They were the following: cortisol, 11-deoxycortisol, 21-deoxycortisol, dehydroepiandrosterone sulfate (DHEAS), dehydroepiandrosterone (DHEA), estradiol, androstenedione, testosterone, dihydrotestosterone (DHT), 17-hydroxyprogesterone, progesterone and corticosterone. The most striking differences were observed for testosterone that showed a more than 200-time increase in women receiving letrozole. Estradiol was conversely reduced to a third. CONCLUSIONS: The endocrine microenvironment surrounding oocytes is markedly perturbed by the concomitant assumption of letrozole. Robust clinical evaluation is pressingly needed to rule out any detrimental effect on the chance of live birth with the use of these oocytes.

Folliculogenesis in random start protocols for oocytes cryopreservation: quantitative and qualitative aspects.

Random start protocols are commonly used for oocytes cryopreservation in women with cancer. However, evidence to support their effectiveness is yet modest. This study aims to compare the quality of ovarian response between the ovary carrying the dominant follicle or the corpus luteum (active ovary) and the contralateral ovary (resting ovary). Women with a diagnosis of malignancy who underwent oocytes cryopreservation were reviewed. The main inclusion criterion was the presence of a unilateral dominant follicle or a unilateral corpus luteum on the first day of ovarian hyperstimulation. The primary outcome was the number of mature oocytes retrieved. Intra-patient comparisons between the two ovaries were made using the nonparametric Wilcoxon test for paired data. Forty-three women were included. The number of mature oocytes retrieved from the active and the resting ovaries did not differ, the median [interquartile range-IQR] being 4 [2-7] and 5 [2-8], respectively (p = 0.09). The rate [IQR] of mature oocytes per developed follicle was 58% [40-80%] and 65% [33-87%], respectively (p = 0.42). In addition, no significant difference emerged when repeating the analyses separately for women carrying dominant follicles and for those carrying corpora lutea. This study failed to detect any detrimental effect of the presence of a dominant follicle or a corpus luteus on the ovarian response to hyperstimulation, thus supporting the validity of random start protocols.

Post-Thaw Day 5 Blastocyst Culture Time Prior to Transfer Does Not Affect Assisted Reproduction Technology (ART) Outcomes in Frozen-Thawed Embryo Transfer Cycles.

The frozen embryo transfer (FET) technique has been progressively used more worldwide due to improved culture conditions, as well as enhanced survival rates after vitrification. However, little is known about the effect of the post-thaw blastocyst culture duration prior to transfer on live birth rate in FET cycles. In this retrospective observational study, we evaluated the influence of two distinct post-thaw blastocyst culture spans (2-4 h versus 20-22 h) on clinical pregnancy and live birth rate. A total of n = 1927 frozen-warmed cycles were included in the analysis. Among those, n = 885 warmed blastocysts were cultured for 2-4 h, and n = 1029 were kept in culture for 20-22 h prior to transfer; the remaining blastocysts did not survive the warming protocol. We observed no significant differences in live birth and clinical pregnancy rates between the two groups. The blastocyst morphological evaluation at transfer improved following the longer culture time. No differences between the two groups were found also for gestational and neonatal outcomes. This work shows that different post-thaw embryo culture timings do not negatively impact pregnancy outcomes. Overall, these results are important in the context of the embryological laboratory in order to better organize the workflow and avoid unnecessary timing-related workload.