Preimplantation genetic testing is not a preferred recommendation for patients with X chromosome abnormalities.

Should women with X chromosome abnormalities (XCAs) be recommended to have embryos selected by both morphological and cytogenetic assessment through preimplantation genetic testing (PGT) rather than morphological assessment only in conventional IVF/ICSI treatment? PGT is not a preferred recommendation for women with XCAs in the absence of other PGT indications. XCAs are the most frequent sort of chromosomal aberrations in infertile women. Patients with a complete or partial absence of one X chromosome, diagnosed as Turner Syndrome (TS), demonstrate low spontaneous pregnancy rates (5-7%) and high miscarriage rates (22.8-30.8%), as well as high chances of birth defects (20%). PGT is known to improve pregnancy rates and decrease the incidence of miscarriage in couples with chromosomal aberrations such as Robertsonian and reciprocal translocations and Klinefelter Syndrome. A retrospective cohort study was conducted with 394 women with XCAs and undergoing their first oocyte retrieval and first embryo transfer cycle from June 2011 to August 2019 in the Reproductive Hospital Affiliated to Shandong University. Pregnancy outcomes were compared between the conventional IVF/ICSI group (n = 284) and the PGT group (n = 110) in the first fresh or frozen embryo transfer cycle for each woman with XCAs. Three platforms were applied in PGT: fluorescence in situ hybridisation (FISH, n = 34), array comparative genomic hybridisation (aCGH, n = 24) and next-generation sequencing (NGS, n = 51). The embryo aneuploidy rate and distribution of embryonic chromosomal aberrations revealed by aCGH or NGS were analysed and stratified by maternal age and type of XCAs to assess the effect of maternal XCAs on embryo karyotypes. The live birth rate (LBR) per embryo transfer was similar between the PGT group and IVF/ICSI group both in the first cycle of fresh or frozen embryo transfer respectively (39.13% in PGTFISH vs 42.58% in IVF/ICSI, Padj=0.558; 66.67% in PGTFISH vs 52.08% in PGTaCGH/NGS vs 53.06% in IVF/ICSI, Padj=0.756), as was the clinical pregnancy rate (60.87% in PGTFISH vs 50.97% in IVF/ICSI, Padj =0.672; 88.89% in PGTFISH vs 58.33% in PGTaCGH/NGS vs 69.39% in IVF/ICSI, Padj =0.480) and the pregnancy loss rate (35.71% in PGTFISH vs 16.46% in IVF/ICSI, Padj =0.136; 12.50% in PGTFISH vs 10.71% in PGTaCGH/NGS vs 23.53% in IVF/ICSI, Padj =0.352). The rates of maternal and neonatal complications were also comparable between the PGT and IVF/ICSI groups with fresh and frozen transfers respectively (10.00% vs 8.85%, P = 1.000; 21.74% vs 14.55%, P = 0.272). Intriguingly, the distribution of embryonic chromosome abnormalities was more frequent on autosomes 22 (20.39%), 21 (18.45%) and 16 (17.47%), compared with the X chromosome (8.73%). Selection bias is an inherent drawback of a retrospective study. First, our participants hosted 4.84% X chromosome mosaicism with few typical somatic anomalies of TS. Second, the incidences of history of recurrent miscarriage and abnormal offspring in the PGT group were higher than in IVF/ICSI group although binary logistic regression analysis was performed to attenuate the modifying effect of confounding factors. Third, FISH performed in this study only used X/Y probes and lacked the reference of autosome, which might have resulted in misdiagnosis and bias. Finally, intrinsic disadvantages could not be totally avoided due to the retrospective nature of this study. In the current study, comparable pregnancy outcomes were revealed among a large cohort of women with XCAs undergoing their first cycles of PGT or conventional IVF/ICSI treatment. Moreover, the X chromosome abnormality was illustrated to cause no higher frequency of aberrations in embryos. Our data provided perspectives for genetic and reproductive counselling to XCAs individuals and their families. This work was supported by National Research and Development Plan (2016YFC1000604 and 2017YFC1001100), the National Natural Science Foundation of China (81701406), Shandong Science Fund for Distinguished Young Scholars (JQ201720), Taishan Scholars Program for Young Experts of Shandong Province (tsqn20161069) and Projects of Medical and Health Technology Development Program in Shandong Province (202005010520, 202005010523 and 2016WS0368). There is no conflict of interest to declare. N/A.

Li C ，Dang Y ，Li J ，Li H ，Zhu Y ，Qin Y ... -  《-》

Preimplantation genetic testing for aneuploidy: a comparison of live birth rates in patients with recurrent pregnancy loss due to embryonic aneuploidy or recurrent implantation failure.

Can preimplantation genetic testing for aneuploidy (PGT-A) improve the live birth rate and reduce the miscarriage rate in patients with recurrent pregnancy loss (RPL) caused by an abnormal embryonic karyotype and recurrent implantation failure (RIF)? PGT-A could not improve the live births per patient nor reduce the rate of miscarriage, in both groups. PGT-A use has steadily increased worldwide. However, only a few limited studies have shown that it improves the live birth rate in selected populations in that the prognosis has been good. Such studies have excluded patients with RPL and RIF. In addition, several studies have failed to demonstrate any benefit at all. PGT-A was reported to be without advantage in patients with unexplained RPL whose embryonic karyotype had not been analysed. The efficacy of PGT-A should be examined by focusing on patients whose previous products of conception (POC) have been aneuploid, because the frequencies of abnormal and normal embryonic karyotypes have been reported as 40-50% and 5-25% in patients with RPL, respectively. A multi-centre, prospective pilot study was conducted from January 2017 to June 2018. A total of 171 patients were recruited for the study: an RPL group, including 41 and 38 patients treated respectively with and without PGT-A, and an RIF group, including 42 and 50 patients treated respectively with and without PGT-A. At least 10 women in each age group (35-36, 37-38, 39-40 or 41-42 years) were selected for PGT-A groups. All patients and controls had received IVF-ET for infertility. Patients in the RPL group had had two or more miscarriages, and at least one case of aneuploidy had been ascertained through prior POC testing. No pregnancies had occurred in the RIF group, even after at least three embryo transfers. Trophectoderm biopsy and array comparative genomic hybridisation (aCGH) were used for PGT-A. The live birth rate of PGT-A and non-PGT-A patients was compared after the development of blastocysts from up to two oocyte retrievals and a single blastocyst transfer. The miscarriage rate and the frequency of euploidy, trisomy and monosomy in the blastocysts were noted. There were no significant differences in the live birth rates per patient given or not given PGT-A: 26.8 versus 21.1% in the RPL group and 35.7 versus 26.0% in the RIF group, respectively. There were also no differences in the miscarriage rates per clinical pregnancies given or not given PGT-A: 14.3 versus 20.0% in the RPL group and 11.8 versus 0% in the RIF group, respectively. However, PGT-A improved the live birth rate per embryo transfer procedure in both the RPL (52.4 vs 21.6%, adjusted OR 3.89; 95% CI 1.16-13.1) and RIF groups (62.5 vs 31.7%, adjusted OR 3.75; 95% CI 1.28-10.95). Additionally, PGT-A was shown to reduce biochemical pregnancy loss per biochemical pregnancy: 12.5 and 45.0%, adjusted OR 0.14; 95% CI 0.02-0.85 in the RPL group and 10.5 and 40.9%, adjusted OR 0.17; 95% CI 0.03-0.92 in the RIF group. There was no difference in the distribution of genetic abnormalities between RPL and RIF patients, although double trisomy tended to be more frequent in RPL patients. The sample size was too small to find any significant advantage for improving the live birth rate and reducing the clinical miscarriage rate per patient. Further study is necessary. A large portion of pregnancy losses in the RPL group might be due to aneuploidy, since PGT-A reduced the overall incidence of pregnancy loss in these patients. Although PGT-A did not improve the live birth rate per patient, it did have the advantage of reducing the number of embryo transfers required to achieve a similar number live births compared with those not undergoing PGT-A. This study was supported by the Japan Society of Obstetrics and Gynecology and grants from the Japanese Ministry of Education, Science, and Technology. There are no conflicts of interest to declare. N/A.

Sato T ，Sugiura-Ogasawara M ，Ozawa F ，Yamamoto T ，Kato T ，Kurahashi H ，Kuroda T ，Aoyama N ，Kato K ，Kobayashi R ，Fukuda A ，Utsunomiya T ，Kuwahara A ，Saito H ，Takeshita T ，Irahara M ... -  《-》

Preimplantation genetic testing for aneuploidy by microarray analysis of polar bodies in advanced maternal age: a randomized clinical trial.

Verpoest W ，Staessen C ，Bossuyt PM ，Goossens V ，Altarescu G ，Bonduelle M ，Devesa M ，Eldar-Geva T ，Gianaroli L ，Griesinger G ，Kakourou G ，Kokkali G ，Liebenthron J ，Magli MC ，Parriego M ，Schmutzler AG ，Tobler M ，van der Ven K ，Geraedts J ，Sermon K ... -  《-》

Leave the past behind: women's reproductive history shows no association with blastocysts' euploidy and limited association with live birth rates after euploid embryo transfers.

Is there an association between patients' reproductive history and the mean euploidy rates per biopsied blastocysts (m-ER) or the live birth rates (LBRs) per first single vitrified-warmed euploid blastocyst transfers? Patients' reproductive history (as annotated during counselling) showed no association with the m-ER, but a lower LBR was reported after euploid blastocyst transfer in women with a history of repeated implantation failure (RIF). Several studies have investigated the association between the m-ER and (i) patients' basal characteristics, (ii) ovarian stimulation strategy and dosage, (iii) culture media and conditions, and (iv) embryo morphology and day of full blastocyst development. Conversely, the expected m-ER due to women's reproductive history (previous live births (LBs), miscarriages, failed IVF cycles and transfers, and lack of euploid blastocysts among prior cohorts of biopsied embryos) still needs investigations. Yet, this information is critical to counsel new patients about a first cycle with preimplantation genetic testing for aneuploidy (PGT-A), but even more so after former adverse outcomes to prevent treatment drop-out. This observational study included all patients undergoing a comprehensive chromosome testing (CCT)-based PGT-A cycle with at least one biopsied blastocyst in the period April 2013-December 2019 at a private IVF clinic (n = 2676 patients undergoing 2676 treatments and producing and 8151 blastocysts). m-ER were investigated according to women's reproductive history of LBs: no/≥1, miscarriages: no/1/>1; failed IVF cycles: no/1/2/>2, and implantation failures after previous transfers: no/1/2/>2. Among the 2676 patients included in this study, 440 (16%) had already undergone PGT-A before the study period; the data from these patients were further clustered according to the presence or absence of euploid embryo(s) in their previous cohort of biopsied blastocysts. The clinical outcomes per first single vitrified-warmed euploid blastocyst transfers (n =1580) were investigated according to the number of patients' previous miscarriages and implantation failures. The procedures involved in this study included ICSI, blastocyst culture, trophectoderm biopsy without hatching in Day 3, CCT-based PGT-A without reporting segmental and/or putative mitotic (or mosaic) aneuploidies and single vitrified-warmed euploid blastocyst transfer. For statistical analysis, Mann-Whitney U or Kruskal-Wallis tests, as well as linear regressions and generalised linear models among ranges of maternal age at oocyte retrieval were performed to identify significant differences for continuous variables. Fisher's exact tests and multivariate logistic regression analyses were instead used for categorical variables. Maternal age at oocyte retrieval was the only variable significantly associated with the m-ER. We defined five clusters (<35 years: 66 ± 31%; 35-37 years: 58 ± 33%; 38-40 years: 43 ± 35%; 40-42 years: 28 ± 34%; and >42 years: 17 ± 31%) and all analyses were conducted among them. The m-ER did not show any association with the number of previous LBs, miscarriages, failed IVF cycles or implantation failures. Among patients who had already undergone PGT-A before the study period, the m-ER did not associate with the absence (or presence) of euploid blastocysts in their former cohort of biopsied embryos. Regarding clinical outcomes of the first single vitrified-warmed euploid blastocyst transfer, the implantation rate was 51%, the miscarriage rate was 14% and the LBR was 44%. This LBR was independent of the number of previous miscarriages, but showed a decreasing trend depending on the number of previous implantation failures, reaching statistical significance when comparing patients with >2 failures and patients with no prior failure (36% versus 47%, P < 0.01; multivariate-OR adjusted for embryo quality and day of full blastocyst development: 0.64, 95% CI 0.48-0.86, P < 0.01). No such differences were shown for previous miscarriage rates. The sample size for treatments following a former completed PGT-A cycle should be larger in future studies. The data should be confirmed from a multicentre perspective. The analysis should be performed also in non-PGT cycles and/or including patients who did not produce blastocysts, in order to investigate a putative association between women's reproductive history with outcomes other than euploidy and LBRs. These data are critical to counsel infertile couples before, during and after a PGT-A cycle, especially to prevent treatment discontinuation due to previous adverse reproductive events. Beyond the 'maternal age effect', the causes of idiopathic recurrent pregnancy loss (RPL) and RIF are likely to be endometrial receptivity and selectivity issues; transferring euploid blastocysts might reduce the risk of a further miscarriage, but more information beyond euploidy are required to improve the prognosis in case of RIF. No funding was received and there are no competing interests. N/A.

Cimadomo D ，Capalbo A ，Dovere L ，Tacconi L ，Soscia D ，Giancani A ，Scepi E ，Maggiulli R ，Vaiarelli A ，Rienzi L ，Ubaldi FM ... -  《-》

Minimizing mosaicism: assessing the impact of fertilization method on rate of mosaicism after next-generation sequencing (NGS) preimplantation genetic testing for aneuploidy (PGT-A).

Palmerola KL ，Vitez SF ，Amrane S ，Fischer CP ，Forman EJ ... -  《-》