Preimplantation genetic testing for aneuploidy (PGT-A) is an emerging technology that aims to identify euploid embryos for transfer, reducing the risk of embryonic chromosomal abnormalities. However, the clinical benefits of PGT-A in recurrent pregnancy failure (RPF) patients, particularly in young RPF patients, remains uncertain.
This meta-analysis aimed to determine whether RPF patients undergoing PGT-A had better clinical outcomes compared to those not undergoing PGT-A, thus assessing the value of PGT-A in clinical practice.
We systematically searched PubMed, the Cochrane Library, China National Knowledge Infrastructure (CNKI), Wanfang Data, and VIP Database for Chinese Technical Periodicals (VIP) from 2002 to 2022. Thirteen published studies involving 930 RPF patients screened using PGT-A and over 1,434 RPF patients screened without PGT-A were included in this meta-analysis. Clinical outcomes were evaluated based on embryo transfers after PGT-A (n=1,015) and without PGT-A (n=1,799).
The PGT-A group demonstrated superior clinical outcomes compared to the in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) group. The PGT-A group had a significantly higher implantation rate (IR) (RR=2.01, 95% CI: [1.73; 2.34]), clinical pregnancy rate (CPR) (RR=1.53, 95% CI: [1.36; 1.71]), ongoing pregnancy rate (OPR) (RR=1.76, 95% CI: [1.35; 2.29]), live birth rate (LBR) (RR=1.75, 95% CI: [1.51; 2.03]), and significantly lower clinical miscarriage rate (CMR) (RR=0.74, 95% CI: [0.54; 0.99]). Subgroup analysis based on patient age (under 35 years and 35 years or older) showed that both PGT-A subgroups had significantly better CPR (P<0.01) and LBR (P<0.05) values compared to the IVF/ICSI groups.
This meta-analysis demonstrates that PGT-A in RPF patients, is associated with improved clinical outcomes, including higher IR, CPR, OPR, and LBR values, and lower CMR compared to the IVF/ICSI group. These findings support the positive clinical application of PGT-A in RPF patients.
http://INPLASY.com, identifier INPLASY 202320118.

Chromosomal mosaicism becomes a common phenomenon in Preimplantaion genetic testing (PGT). This meta-analysis was conducted to study which feature of chromosomal mosaicism was compatible for embryo transfer.
After searching the database PubMed, Embase, CCTR and related reviews up until May 2021. Two reviewers extracted relevant information and assessed study quality by the Newcastle-Ottawa scale independently. Summary Odd Radios (OR) were calculated using fixed- or random-effects models for clinical outcomes. A network meta-analysis compared the clinical outcomes of different chromosomes.
A total of six studies with 1,106 cycles of single mosaic embryo transferred were included. Significant results of implantation rate (IR), miscarriage rate (MR), and ongoing pregnancy/live birth rate (OP/LBR) were observed when comparing embryos with mosaicism level < 50% and ≥ 50% [OR 1.42, 95% CI (1.06, 1.89); OR 0.45, 95% CI (0.27, 0.75); OR 1.74, 95% CI (1.28, 2.37)], and embryos with mosaicism with only affecting segmental chromosome(s) and only involving whole chromosome(s) [OR 1.31, 95% CI (1.01, 1.71); OR 0.57, 95% CI (0.36, 0.93); OR 1.51, 95% CI (1.15, 2.00)]. Embryos with only mosaic gains or losses had significant higher IR and OP/LBR than complex mosaicism [Gains vs complex: OR 1.75, 95% CI (1.20, 2.54); OR 1.73, 95% CI (1.16, 2.58). Losses vs complex: OR 1.90, 95% CI (1.34, 2.71); OR 2.10, 95% CI (1.44, 3.07)]. Mosaic embryos with only one chromosome involved had significant favorable outcomes of IR and OP/LBR than with three or more chromosomes involved [OR 1.76, 95% CI (1.23, 2.52); OR 1.86, 95% CI (1.25,2.78)]. Chr. 7, Chr. 2, Chr. 1, Chr. 18, Chr. 11, Chr. X, Chr. 13, Chr. 14, Chr. 12, and Chr. 9 were considered as prioritized chromosomes of mosaic embryos for transfer.
This analysis support the embryos with mosaicism level ≥ 50%, whole chromosome(s) involved, multiple mosaic abnormalities were associated with worse pregnancy outcomes. Mosaicism level of 50% could be used as a threshold to assess the mosaic embryos.

BACKGROUND: Delayed parenthood, by both women and men, has become more common in developed countries. The adverse effect of advanced maternal age on embryo aneuploidy and reproductive outcomes is well known. However, whether there is an association between paternal age (PA) and embryonic chromosomal aberrations remains controversial. Oocyte donation (OD) is often utilized to minimize maternal age effects on oocyte and embryo aneuploidy, thus providing an optimal model to assess the effect of PA. Several studies have revealed a higher than expected rate of aneuploidy in embryos derived from young oocyte donors, which warrants examination as to whether this may be attributed to advanced PA (APA).
UNASSIGNED: The objective of this systematic review and individual patient data (IPD) meta-analysis is to evaluate existing evidence regarding an association between PA and chromosomal aberrations in an OD model.
METHODS: This review was conducted according to PRISMA guidelines for systematic reviews and meta-analyses. Medline, Embase and Cochrane databases were searched from inception through March 2020 using the (MeSH) terms: chromosome aberrations, preimplantation genetic screening and IVF. Original research articles, reporting on the types and/or frequency of chromosomal aberrations in embryos derived from donor oocytes, including data regarding PA, were included. Studies reporting results of IVF cycles using only autologous oocytes were excluded. Quality appraisal of included studies was conducted independently by two reviewers using a modified Newcastle-Ottawa Assessment Scale. A one-stage IPD meta-analysis was performed to evaluate whether an association exists between PA and aneuploidy. Meta-analysis was performed using a generalized linear mixed model to account for clustering of embryos within patients and clustering of patients within studies.
RESULTS: The search identified 13 032 references, independently screened by 2 reviewers, yielding 6 studies encompassing a total of 2637 IVF-OD cycles (n = 20 024 embryos). Two \'low\' quality studies using FISH to screen 12 chromosomes on Day 3 embryos (n = 649) reported higher total aneuploidy rates and specifically higher rates of trisomy 21, 18 and 13 in men ≥50 years. One \'moderate\' and three \'high\' quality studies, which used 24-chromosome screening, found no association between PA and aneuploidy in Day 5/6 embryos (n = 12 559). The IPD meta-analysis, which included three \'high\' quality studies (n = 10 830 Day 5/6 embryos), found no significant effect of PA on the rate of aneuploidy (odds ratio (OR) 0.97 per decade of age, 95% CI 0.91-1.03), which was robust to sensitivity analyses. There was no association between PA and individual chromosome aneuploidy or segmental aberrations, including for chromosomes X and Y (OR 1.06 per decade of age, 95% CI 0.92-1.21). Monosomy was most frequent for chromosome 16 (217/10802, 2.01%, 95% CI 1.76-2.29%) and trisomy was also most frequent for chromosome 16 (194/10802, 1.80%, 95% CI 1.56-2.06%).
UNASSIGNED: We conclude, based on the available evidence, that APA is not associated with higher rates of aneuploidy in embryos derived from OD. These results will help fertility practitioners when providing preconception counselling, particularly to older men who desire to have a child.

BACKGROUND: Recently, the Japan Society of Obstetrics and Gynecology initiated a clinical study of preimplantation genetic test for aneuploidy. There will be a great need for a standardized embryo biopsy technique in Japan. However, the gold standard trophectoderm (TE) biopsy procedure has not been established, and this review outlines the clinical use of TE biopsy.
METHODS: Based on literature, the method and associated techniques for TE biopsy, a dissection method of TE cells from blastocysts, were investigated.
RESULTS: Two TE biopsy methods are used, namely assisted hatching (herniating) and non-assisted hatching (direct suction); however, it is not clear which of these methods is superior. It is critical to understand whether the flicking or pulling method is beneficial.
CONCLUSIONS: Non-assisted hatching biopsy method may cause blastocyst collapse with a higher probability, and it may extend the biopsy time. The biopsy procedure should be performed within 3 minutes, and thus direct TE suction may have greater disadvantages. It is a fact that pulling method of TE dissection with laser pulse is simple; however, excess laser shots may induce a higher frequency of mosaicism. It is important to understand that each technique of TE biopsy has benefits and disadvantages.

Aneuploid conceptions constitute the majority of pregnancy failures in women of advanced maternal age. The best way to combat age-related decline in fertility is through preimplantation genetic testing for aneuploidy (PGT-A). PGT-A allows for better embryo selection, which improves implantation rates with single embryo transfer and reduces miscarriage rates. Single embryo transfers decrease multiple gestations and adverse pregnancy outcomes such as preterm or low birth weight infants. Advancements in extended embryo culture, blastocyst biopsy techniques, and 24-chromosome aneuploidy screening platforms have made PGT-A safe and accessible for all patients who undergo in vitro fertilization. Improved genomic coverage of new sequencing platforms, such as next-generation sequencing, has increased the identification and diagnosis of mosaicism and partial aneuploidies in preimplantation embryos. Mosaic embryos have decreased viability compared to euploid embryos when transferred, but some mosaic embryos result in normal live births. Whole genome amplification artifacts may contribute to a misdiagnosis of mosaicism, or some mosaic embryos may self-correct to euploid after implantation. For this reason, patients without euploid embryos should be given the option of transferring mosaic embryos after genetic counseling. Further research is needed to characterize which mosaic embryos may be viable.