Extended application of PGT-M strategies for small pathogenic CNVs.

PURPOSE: The preimplantation genetic testing for aneuploidy (PGT-A) platform is not currently available for small copy-number variants (CNVs), especially those < 1 Mb. Through strategies used in PGT for monogenic disease (PGT-M), this study intended to perform PGT for families with small pathogenic CNVs. METHODS: Couples who carried small pathogenic CNVs and underwent PGT at the Reproductive and Genetic Hospital of CITIC-Xiangya (Hunan, China) between November 2019 and April 2023 were included in this study. Haplotype analysis was performed through two platforms (targeted sequencing and whole-genome arrays) to identify the unaffected embryos, which were subjected to transplantation. Prenatal diagnosis using amniotic fluid was performed during 18-20 weeks of pregnancy. RESULTS: PGT was successfully performed for 20 small CNVs (15 microdeletions and 5 microduplications) in 20 families. These CNVs distributed on chromosomes 1, 2, 6, 7, 13, 15, 16, and X with sizes ranging from 57 to 2120 kb. Three haplotyping-based PGT-M strategies were applied. A total of 89 embryos were identified in 25 PGT cycles for the 20 families. The diagnostic yield was 98.9% (88/89). Nineteen transfers were performed for 17 women, resulting in a 78.9% (15/19) clinical pregnancy rate after each transplantation. Of the nine women who had healthy babies, eight accepted prenatal diagnosis and the results showed no related pathogenic CNVs. CONCLUSION: Our results show that the extended haplotyping-based PGT-M strategy application for small pathogenic CNVs compensated for the insufficient resolution of PGT-A. These three PGT-M strategies could be applied to couples with small pathogenic CNVs.

Effect of lifestyle or metformin interventions before IVF/ICSI treatment on infertile women with overweight/obese and insulin resistance: a factorial design randomised controlled pilot trial.

BACKGROUND: For infertile women with overweight/obesity and insulin resistance (IR), it is uncertain whether intervention before infertility treatment can improve live birth rate (LBR). We implemented a factorial-design study to explore the effectiveness of lifestyle and metformin interventions. This pilot study aimed to evaluate the feasibility of a definitive study. METHODS: We randomised 80 women without polycystic ovarian syndrome (PCOS) who planned to start their first or second IVF/ICSI treatment with a body mass index ≥ 25 kg/m2 and IR. Participants were randomised (1:1:1:1) into four groups: (A) lifestyle intervention, (B) metformin intervention, (C) lifestyle + metformin intervention, or (D) no intervention. All interventions were performed before IVF/ICSI treatment. RESULTS: During 10 months, 114 women were screened and eligible; 80 were randomised, and 72 received the assigned treatment. The recruitment rate was 70.18% (80/114, 95% CI 61.65%-78.70%). An average of 10 participants were randomised each month. None of the participants crossed over from one group to another. Approximately 93.15% (68/73) of the participants achieved good intervention compliance. Only 77.78% (56/72) of the recruited participants started infertility treatment after achieving the goal of the intervention. All randomised participants completed the follow-up. Mild adverse events after metformin administration were reported in 43.24% (16/37) of the cases, although no serious adverse events related to the interventions occurred. The LBR for groups A + C and B + D were 33.33% (12/36) and 33.33% (12/36) (RR = 1.00, 95%CI:0.52-1.92) (lifestyle intervention effect). The LBR for groups B + C and A + D were 43.24% (16/37) and 22.86% (8/35) (RR = 1.89, 95% CI:0.93-3.86) (metformin intervention effect). There was no evidence for an intervention interaction between lifestyle and metformin. We cannot yet confirm the effects of lifestyle, metformin, or their interaction owing to the insufficient sample size in this pilot study. CONCLUSIONS: Instituting a 2 × 2 factorial design randomized controlled trial (RCT) is feasible, as the pilot study showed a high recruitment rate and compliance. There is no evidence that lifestyle or metformin improves live birth, and adequately powered clinical trials are required. TRIAL REGISTRATION: clinicaltrials.gov NCT03898037. Registered: April 1, 2019.

Euploidy rates among preimplantation genetic testing for aneuploidy cycles with oral dydrogesterone primed ovarian stimulation or GnRH antagonist protocol.

RESEARCH QUESTION: Do differences exist in euploidy rates in preimplantation genetic testing for aneuploidy (PGT-A) cycles with oral dydrogesterone primed ovarian stimulation protocol or the flexible gonadotropin-releasing hormone (GnRH) antagonist protocol? DESIGN: A retrospective cohort study. Patients received the oral dydrogesterone or the GnRH antagonist in the first PGT-A cycle between November 2017 and May 2019. Propensity matching was used to identify a propensity-matched antagonist group based on age, BMI and AMH with a 1:1 ratio. The primary outcome was the rate of euploid embryos. RESULTS: A total of 780 cycles were included, consisting of 390 cycles receiving dydrogesterone and 390 cycles receiving GnRH antagonist protocol. No significant difference was found in patient baseline and cycle characteristics in the two groups. No statistical difference was found in the number of oocytes retrieved, metaphase II oocytes, embryos biopsied and embryo testing between the two groups. As no biopsy blastocysts formed in some cycles, only 262 cycles in the study group and 263 cycles in the antagonist group received next-generation sequencing testing, respectively. Similar to our overall data, the euploid rate per embryo biopsied was not significantly different. No significant differences were found between the two groups after stratifying by age and controlling for PGT-A testing modality. CONCLUSIONS: Ovulation inhibition by exogenous progestins in ovarian stimulation cycles should, therefore, be considered a valid modality in freeze-all PGT-A cycles, in view of its demonstrated effectiveness and known safety enhancement.

Single embryo transfer by Day 3 time-lapse selection versus Day 5 conventional morphological selection: a randomized, open-label, non-inferiority trial.

STUDY QUESTION: Does single cleavage-stage (Day 3) embryo transfer using a time-lapse (TL) hierarchical classification model achieve comparable ongoing pregnancy rates (OPR) to single blastocyst (Day 5) transfer by conventional morphological (CM) selection? SUMMARY ANSWER: Day 3 single embryo transfer (SET) with a hierarchical classification model had a significantly lower OPR compared with Day 5 SET with CM selection. WHAT IS KNOWN ALREADY: Cleavage-stage SET is an alternative to blastocyst SET. Time-lapse imaging assists better embryo selection, based on studies of pregnancy outcomes when adding time-lapse imaging to CM selection at the cleavage or blastocyst stage. STUDY DESIGN, SIZE, DURATION: This single-centre, randomized, open-label, active-controlled, non-inferiority study included 600 women between October 2015 and April 2017. PARTICIPANTS/MATERIALS, SETTING, METHODS: Eligible patients were Chinese females, aged ≤36 years, who were undergoing their first or second fresh IVF cycle using their own oocytes, and who had FSH levels ≤12 IU/mL on Day 3 of the cycle and 10 or more oocytes retrieved. Patients who had underlying uterine conditions, oocyte donation, recurrent pregnancy loss, abnormal oocytes or <6 normally fertilized embryos (2PN) were excluded from the study participation. Patients were randomized 1:1 to either the cleavage-stage SET with a time-lapse hierarchical classification model for selection (D3 + TL) or blastocyst SET with CM selection (D5 + CM). All normally fertilized zygotes were cultured in Primo Vision. The study was conducted at a tertiary IVF centre (CITIC-Xiangya) and OPR was the primary outcome. MAIN RESULTS AND THE ROLE OF CHANCE: A total of 600 patients were randomized to the two groups, among which 585 (D3 + TL = 290, D5 + CM = 295) were included in the Modified-intention-to-treat (mITT) population and 517 (D3 + TL = 261, D5 + CM = 256) were included in the PP population. In the per protocol (PP) population, OPR was significantly lower in the D3 group (59.4%, 155/261) than in the D5 group (68.4%, 175/256) (difference: -9.0%, 95% CI: -17.1%, -0.7%, P = 0.03). Analysis in mITT population showed a marginally significant difference in the OPR between the D3 + TL and D5 + CM groups (56.6 versus 64.1%, difference: -7.5%, 95% CI: -15.4%, 0.4%, P = 0.06). The D3 + TL group resulted in a markedly lower implantation rate than the D5 + CM group (64.4 versus 77.0%; P = 0.002) in the PP analysis, however, the early miscarriage rate did not significantly differ between the two groups. LIMITATIONS, REASONS FOR CAUTION: The study lacked a direct comparison between time-lapse and CM selections at cleavage-stage SET and was statistically underpowered to detect non-inferiority. The subject's eligibility criteria favouring women with a good prognosis for IVF weakened the generalizability of the results. WIDER IMPLICATIONS OF THE FINDINGS: The OPR from Day 3 cleavage-stage SET using hierarchical classification time-lapse selection was significantly lower compared with that from Day 5 blastocyst SET using conventional morphology, yet it appeared to be clinically acceptable in women underwent IVF. STUDY FUNDING/COMPETING INTEREST(S): This study is supported by grants from Ferring Pharmaceuticals and the Program for New Century Excellent Talents in University, China. TRIAL REGISTRATION NUMBER: ChiCTR-ICR-15006600. TRIAL REGISTRATION DATE: 16 June 2015. DATE OF FIRST PATIENT'S ENROLMENT: 1 October 2015.