Preimplantation Genetic Screening Cycles Research Articles

Variations in chromosomal aneuploidy rates in IVF blastocysts and early spontaneous abortion chorionic villi.

To compare chromosomal aberrations and aneuploidy features in (i) blastocysts following intracytoplasmic sperm injection (ICSI) and trophectoderm (TE) biopsy using preimplantation genetic screening (PGS) and (ii) early spontaneous abortion chorionic villus biopsies (SA-CVB) using single-nucleotide polymorphism (SNP) array detection. We retrospectively reviewed the data for 1014 TEs from 220 PGS cycles and 1724 SA-CVBs originating from naturally pregnant couples and patients undergoing assisted reproductive technology (ART) during 2017 to 2018. SNP array was applied in both PGS and SA-CVBs detection. Aberrations were defined, and the frequency and ratio of each chromosome aberration were compared between the two groups. There were more abnormalities in TEs in the form of complex chromosome aneuploidies and monosomies, while SA-CVBs had more trisomies, sex chromosome abnormalities, and polyploidies. In both groups, chromosomal aneuploidies (including monosomies and trisomies) were confined to chromosomes 14, 15, 16, 18, 21, and 22, but showed varying distributions across the groups. Aneuploidy of chromosome 22 was most frequent in TEs, whereas that of chromosome 16 predominated in SA-CVBs. Among the sex chromosome abnormalities, X monosomies were significantly more prevalent in SA-CVBs. Chromosomal aberrations and aneuploidy manifested specific characteristics that differed between TEs and SA-CVBs, which indicates that distinct chromosomal abnormalities can affect certain developmental stages of embryos. Further analysis is needed to explore the chromosomal mechanisms affecting embryo development and implantation. Such information will help clinical assessments in prenatal diagnosis and reduce the incidence of genetically abnormal fetuses.

The impact of in vitro human embryo fragmentation on blastocyst development and ploidy using Next-Generation Sequencing (NGS)

Introduction The degree of fragmentation has been utilized in non-invasive selection of Day 2 or Day 3 embryos for transfer. Fragmentation happens in both in vitro and in vivo embryo, where anucleate cells of varying size and number are found along with nucleate cells in the embryo. While fragmentation may potentially affect the developmental potential of an embryo, very little evidence has been reported in the literature. This study was carried out to evaluate the effects of embryo fragmentation on the blastulation rate (BR), blastocyst utilization rate (BUR), implantation rate (IR) and euploid rate of the blastocyst. Materials & Methods A total of 438 PGS cycles from January 2017 to December 2017 were retrospectively analyzed. Intracytoplasmic sperm injection (ICSI) was carried out after oocyte retrieval. Normally fertilized (2PN) embryos (n= 3720) were evaluated according to the degree of fragmentation (group 0F: 0 – 5% fragments, group 0/1F: 6 -10% fragments, group 1F: 11 – 15% fragments, group 1/2F: 16 – 20% fragments, group 2F: 21 – 25% fragments and group 2/3F: >25% fragments) at 66 – 68 hours post injection. Following extended culture to blastocyst stage, trophectoderm (TE) biopsy was performed on good or fair graded blastocysts (n=1865) on either Day 5 or Day 6. Pre-implantation Genetic Screening (PGS) using Next-Generation Sequencing (NGS) (Veriseq Protocol, Illumina) was used for aneuploidy screening. A total of 252 euploid or low-level mosaicism blastocysts were transferred and the BR, BUR, IR and the euploidy rate of the blastocyst were evaluated. Results Embryos with higher degree of fragmentation have been found to have a lower BR (81.4%, 73.5%, 60.7%, 47.0%, 31.6% and 12.8%, respectively) and BUR (66.2%, 52.6%, 37.7%, 23.5%, 9.9% and 4.3%, respectively) in our study. We found that embryos with no fragment or lower degree of fragmentation have a higher chance of reaching the blastocyst stage, while most of the embryos with a higher degree of fragmentation were arrested after Day 3. Our study did not show any differences in euploidy rate, mosaicism rate and aneuploidy rate between groups with an average of 67.29%, 8.89% and 25.09% respectively. Transfer of blastocyst with higher degree of fragmentation on Day 3 did not show any significant decrease of in implantation rate. Conclusions In our study, fragmentation has been shown to affect blastocyst development due to unequal allocation of cells. But once a blastocyst develops, there do not seem to be any impact on IR and chromosome abnormalities. Indeed, pregnancies has been reported with the transfer of embryos with a high degree of fragmentation. Our small sample size however, may impact on the validity of this study. As embryo selection solely based on the degree of fragmentation on Day 3 is ineffective, extended culture of all embryos regardless of degree of fragmentation to blastocyst stage is recommended. This will potentially avoid accidental discarding of embryos that are destined to implant and form a pregnancy.

Early blastulation of day 4 embryo correlates with the increased euploid rate of preimplantation genetic screening cycles

ObjectiveIt is known that embryos with faster growing potential, especially in blastocyst development, correlate with the increased euploid rate. Our study investigated the preimplantation genetic screening cycle to analyze the correlation between early blastulation (EB) on day 4 embryo and the euploid rate. Materials and methodsThis is a retrospective study examining 273 biopsied blastocysts after preimplantation genetic screening obtained from 54 patients from March 2013 to March 2017. Of the 273 biopsied embryos, 81 had early blastulation on day 4 and were classified as the EB (+) group, while the other 192 had no early blastulation and were classified as the EB (−) group. Euploid rates were compared between the two groups. A total of 34 single euploid embryos were transferred, with 14 from the EB (+) group and 20 from the EB (−) group. Clinical pregnancy was compared between the groups. ResultsThere is a statistically significant increase in the euploid rate in the EB (+) group (49.4% vs. 34.4%, p = 0.02). The clinical pregnancy rate was also increased in the single euploid embryo transfer group with early blastulation, but did not reach statistical significance (71.4% vs. 50.0%, p = 0.211). ConclusionsEarly blastulation of day 4 embryo correlates significantly with the euploid rate. Early blastulation of day 4 embryo may serve as a potential aid for embryo selection for transfer in preimplantation genetic screening cycles.

Male factor & mosaicism: assessing the contribution of abnormal semen parameters to rate of mosaicism in next generation sequencing (NGS) preimplantation genetic screening (PGS) intracytoplasmic sperm injection (ICSI) cycles

Advances in preimplantation genetic screening (PGS) have led to practices changes in assisted reproductive technology (ART), enabling fertility centers to transfer single embryos while maintaining excellent ongoing pregnancy rates, reducing miscarriage rates, and dramatically reducing ART-associated multiple pregnancies [1,2]. The introduction of next generation sequencing (NGS) has allowed PGS laboratories to assess for embryo mosaicism – although the true incidence and reproductive potential of mosaic embryos is controversial. Severe male factor is known to increase risk of aneuploidy [3]. However, the influence of male factor infertility on mosaicism is unknown at this time. While aneuploidy is mostly due to maternal meiotic errors, mosaicism is likely caused by post-fertilization mitotic errors [4] and abnormal sperm may contribute to an embryo's risk of being mosaic. We sought to examine the influence of abnormal semen parameters on mosaicism in NGS PGS-tested embryos. The purpose of this study was to evaluate rate of mosaic embryo formation in NGS PGS cycles according to semen abnormality. Secondary aims were to assess sex ratio and subtypes of mosaicism in NGS PGS cycles according to semen abnormality. We performed a retrospective review of women undergoing PGS at a single academic fertility center from July 1, 2015 to September 1, 2017. Only intracytoplasmic sperm injection (ICSI) PGS cycles were included. In all cycles, PGS was performed via trophectoderm biopsy on day 5 or 6 and analyzed using NGS at a single reference lab. Patient demographics, fertility testing, cycle characteristics and PGS outcomes were collected. PGS outcomes were compared between oligospermic and non-oligospermic cohorts, between asthenospermic and non-asthenospermic cohorts, and between oligoasthenospermic and normospermic cohorts. 228 ART-ICSI cycles with PGS testing were included for analysis: 130 normospermic, 32 oligospermic, 47 asthenospermic, and 12 oligoasthenospermic cycles, resulting in 374 normospermic, 106 oligospermic, 162 asthenospermic, and 38 oligoasthenospermic biopsied embryos. Baseline characteristics were similar between cohorts with the exception of semen parameters (Tables 1-3). PGS cycles with oligospermia demonstrated a higher proportion of mosaic embryos (36/100, 34%) versus PGS cycles without oligospermia (115/617, 18.6%), p<0.001. PGS cycles with oligoasethenospermia demonstrated a higher proportion of mosaic embryos (15/38, 39.5% versus 88/384, 23.5%, p<0.001) compared to PGS cycles without oligoasthenospermia. Additional PGS outcomes were similar between cohorts (Tables 1-3). Oligoasthenospermia and oligospermia, but not asthenospermia, may increase the risk of mosaic embryos following ART-ICSI cycles with NGS PGS.

High Gonadotropin Dosage Does Not Affect Euploidy and Pregnancy Rates in IVF PGS Cycles With Single Embryo Transfer

(Abstracted from Hum Reprod 2017;32:2209–2217) The most effective and reliable method for embryo selection in in vitro fertilization (IVF) cycles is preimplantation genetic screening (PGS). There is a significant decrease in euploidy and blastulation rates with increasing maternal age.

Duration of blastulation may be associated with ongoing pregnancy rate in single euploid blastocyst transfer cycles

Not all euploid embryos implant, necessitating additional tools to select viable blastocysts in preimplantation genetic screening cycles. In this retrospective cohort study, 129 consecutive patients who underwent 129 single euploid blastocyst transfers in cryopreserved embryo transfer cycles were included. All embryos were individually cultured in a time-lapse incubator from intracytoplasmic sperm injection up to trophoectoderm biopsy. Twenty-three time-lapse morphokinetic variables were tested among patients with (n = 68) or without (n = 61) ongoing pregnancy. All 23 time-lapse morphokinetic variables, apart from duration of blastulation (tB–tSB), were comparable between patients with or without ongoing pregnancy. Duration of blastulation was significantly shorter in patients with ongoing pregnancy (8.1 ± 3.2 versus 9.5 ± 3.4 h; P = 0.014); shorter duration of blastulation remained an independent predictor for ongoing pregnancy, when tested by logistic regression analysis (OR 0.81; 95% CI 0.70 to 0.93). One important limitation of this study, and a reason for caution, is the use of multiple comparisons, which can lead to differences at the 0.05 level simply by chance or random variation. Nonetheless, the study suggests that when more than one euploid blastocyst is available, priority might be given to those with a shorter duration of blastulation.

Preimplantation genetic screening (PGS) with next generation sequencing (NGS) achieves ongoing pregnancy with fewer transfers and total miscarriages compared to non-PGS cycles

To determine the cumulative ongoing pregnancy/live birth rates (OP/LBR) of PGS cycles with NGS compared to non-PGS cycles using an intention to treat analysis. Cohort Study All patients undergoing an oocyte retrieval for IVF or IVF/PGS with NGS and their subsequent frozen embryo transfer (FET) cycles at a single university-based fertility center were collected from 1/2014 through 7/2016. Embryo banking cycles, donor oocyte cycles, cycles utilizing PGS with array comparative genomic hybridization, and IVF cycles with no blastocyst stage embryos were excluded. Cumulative OP/LBRs were calculated per retrieval including up to 4 transfers and analyzed by age-group. IVF/PGS cycles with no euploid embryos available for transfer were included. Secondary outcomes included the number of embryos transferred per cycle, cumulative OP/LBR after the first embryo transfer (ET), and cumulative spontaneous abortion rate (SABR) per clinical pregnancy. Statistical analysis was performed using Fisher’s exact test with P<0.05 considered significant. 2547 cycles meeting inclusion criteria were identified. 844 retrievals and 525 FET cycles were performed in the PGS with NGS group. In the no PGS group, there were 953 retrievals and 225 FET cycles. 242 retrieval cycles did not form blastocysts and were excluded. The number of embryos transferred per cycle was significantly higher in the no PGS group than the PGS with NGS group (1.58±0.69 vs 1.01±0.11, p<0.001). Primary and secondary outcomes are summarized in the table. Per retrieval, there was no statistical difference in cumulative OP/LBR between groups. Pregnancy was achieved more often after the first transfer in women 38-40 years old. The cumulative OP/LBR per retrieved patient with embryos available for transfer was significantly higher for the PGS group over age 35. The cumulative SABR was significantly higher for ages 38-42yo in the no PGS group.Tabled 1Cumulative OP/LBR Per Retrieval (%) by agePGS with NGSNo PGSP- value<3562.6% (97/155)70.1% (169/241)0.1535-3750.3% (86/171)53.8% (78/145)0.6138-4042.4% (109/257)38% (62/163)0.4341-4217.9% (29/162)21.1% (15/71)0.68>427.1% (7/98)10.3% (8/78)0.64OP/LBR after 1st ET per Retrieval (%) by agePGS with NGSNo PGSP- value<3554.2% (84/155)47.3% (114/241)0.2235-3745.6% (78/171)40.7% (59/145)0.4438-4039.3% (101/257)29.4% (48/163)0.04941-4216% (26/162)18.3% (13/71)0.8>426.1% (6/98)9% (7/78)0.66Cumulative OP/LBR per retrieved patient with embryos available for transfer (%) by agePGS with NGSNo PGSP-value<3574.6% (97/130)70.1% (169/241)0.4335-3771.1% (86/121)53.8% (78/145)0.00638-4070.8% (109/154)38% (62/163)<0.00141-4267.4% (29/43)21.1% (15/71)<0.001>4246.7% (7/15)10.3% (8/78)0.004Cumulative SABR per clinical pregnancy (%) by agePGS with NGSno PGSP- value<3510.2% (11/108)14.5% (28/193)0.3735-3714.9% (15/101)20.4% (20/98)0.3638-4011.7% (14/120)28.6% (24/84)0.00441-4214.7% (5/34)46.4% (13/28)0.013>4212.5% (1/8)55.6% (10/18)0.1 Open table in a new tab Overall, cumulative OP/LBRs are similar in women undergoing IVF with or without PGS, but IVF cycles without PGS have significantly more embryos transferred per cycle. Retrievals utilizing PGS with NGS result in OP/LB with fewer embryo transfers in women 38-40 years old and fewer miscarriages in women ages 38-42.

Impact of preimplantation genetic screening on donor oocyte-recipient cycles in the United States

Our objective was to estimate the contribution of preimplantation genetic screening to invitro fertilization pregnancy outcomes in donor oocyte-recipient cycles. This was a retrospective cross-sectional study of US national data from the Society for Assisted Reproductive Technology Clinic Outcome Reporting System between 2005 and 2013. Society for Assisted Reproductive Technology Clinic Outcome Reporting relies on voluntarily annual reports by more than 90% of US invitro fertilization centers. We evaluated pregnancy and live birth rates in donor oocyte-recipient cycles after the first embryo transfer with day 5/6 embryos. Statistical models, adjusted for patient and donor ages, number of embryos transferred, race, infertility diagnosis, and cycle year were created to compare live birth rates in 392 preimplantation genetic screening and 20,616 control cycles. Overall, pregnancy and live birth rates were significantly lower in preimplantation genetic screening cycles than in control cycles. Adjusted odds of live birth for preimplantation genetic screening cycles were reduced by 35% (odds ratio, 0.65, 95% confidence interval, 0.53-0.80; P < .001). Preimplantation genetic screening, as practiced in donor oocyte-recipient cycles over the past 9 years, has not been associated with improved odds of live birth or reduction in miscarriage rates.

Initial maternal serum human chorionic gonadotropin levels in pregnancies achieved after assisted reproductive technology are higher after preimplantation genetic screening and after frozen embryo transfer: a retrospective cohort.

Few published articles have compared initial hCG values across all different types of ART cycles, including cycles with fresh or frozen embryo transfer. No articles have compared initial hCG values in cycles utilizing preimplantation genetic screening (PGS). The purpose of this study is to compare initial hCG values after fresh embryo transfer, frozen embryo transfer, and after PGS. This was a single-center retrospective cohort study at an academically affiliated private IVF center. All fresh and frozen embryo transfers between January 2013 and December 31, 2015 were included. We compared mean initial serum hCG values 14days after oocyte retrieval for fresh cycles and 9days after frozen embryo transfer. We examined cycles of single embryo transfer (SET) and double embryo transfer (DET). Two hundred elven IVF (fresh embryo transfer), 128 FET (frozen embryo transfer cycles, no PGS), and 111 PGS cycles (ovarian stimulation with embryo cryopreservation, PGS, and frozen transfer in a subsequent estrogen-primed cycle) with initial positive hCG values were analyzed. In patients achieving a positive hCG after SET, initial hCG values were higher after PGS compared to FET (182.4 versus 124.0mIU/mL, p=0.02) and IVF (182.4 versus 87.1mIU/mL, p<0.001) as well as FET compared to IVF (124.0 versus 87.1mIU/mL, p<0.01). After DET, initial hCG values were higher after PGS (222.8mIU/mL) compared to FET (182.1mIU/mL, p=0.02) and IVF (131.1mIU/mL, p=0.001). Our study suggests that initial serum hCG values are higher after using PGS and higher after the transfer of a frozen embryo compared to a fresh embryo. This suggests that initial hCG values relate to the chromosomal status of embryos. Initial hCG values may help determine intervention and monitoring later in pregnancy.

Detailed investigation into the cytogenetic constitution and pregnancy outcome of replacing mosaic blastocysts detected with the use of high-resolution next-generation sequencing

To determine the pregnancy outcome potential of mosaic embryos, detected by means of preimplantation genetic screening (PGS) with the use of next-generation sequencing (NGS). Retrospective study. Genetics laboratories. PGS cycles during which either mosaic or euploid embryos were replaced. Blastocysts were biopsied and processed with the use of NGS, followed by frozen embryo transfer. Trophectoderm (TE) biopsies were classified as mosaic if they had 20%-80% abnormal cells. Implantation, miscarriage rates, and ongoing implantation rates (OIRs) were compared between euploid and types of mosaic blastocysts. Complex mosaic embryos had a significantly lower OIR (10%) than aneuploidy mosaic (50%), double aneuploidy mosaic (45%), and segmental mosaic (41%). There was a tendency for mosaics with 40%-80% abnormal cells to have a lower OIR than those with <40% (22% vs. 56%). However, few embryos (n = 34) with a mosaic error in 40%-80% of the TE sample were replaced. There was no difference between monosomic and trisomic mosaics or between entire chromosome mosaicism or segmental mosaicism. Implantation rates were significantly higher (70% vs. 53%), miscarriage rates lower (10% vs. 25%), and OIRs higher (63% vs. 40%) after euploid embryo transfer than after mosaic embryo transfer. Forty-one percent of mosaic embryos produced an ongoing implantation. Complex mosaic blastocysts had a lower OIR than other mosaics. Mosaic monosomies performed as well as mosaic trisomies and mosaic segmental aneuploidies. The results suggest that embryos with >40% abnormal cells and those with multiple mosaic abnormalities (chaotic mosaics) are likely to have lower OIRs and should be given low transfer priority.

Prediction of a reciprocal translocation by preimplantation genetic screening (PGS)

An estimated 1/500 individuals carry a balanced chromosome rearrangement, and this frequency may be as high as 1/100 in the IVF patient population. Balanced translocations typically have no impact on an individual’s health; however, the transmission of unbalanced translocations can cause infertility and miscarriage. Karyotyping is routinely performed for a patient with a history of multiple pregnancy losses, but is not part of the standard workup for the unselected infertility patient. We hypothesize that patterns of segmental aneuploidies found in PGS results can predict a maternal or paternal balanced translocation. The objective of the study is to determine the ability of PGS to predict a previously unknown balanced translocation in one member of the reproductive couple through pattern detection in a cohort of embryos tested. Translocation patterns were identified by observing two or more similar terminal deletions or duplications, with or without complete aneuploidy of that chromosome, in the cohort of embryos tested, using either aCGH or NGS. PGS is unable to predict a translocation when the size of terminal segments is below the resolution of PGS and when the number of embryos tested is too small to allow observable patterns to emerge. Inversion and Robertsonian translocation predictions were not included in this study. We notified the IVF center of the suspected translocation and recommended chromosome analysis. We requested clinical follow up to know if the suspected balanced translocation was confirmed by karyotype. Fourteen PGS cases over a two-year span had patterns predictive of a reciprocal maternal or paternal balanced translocation. The average cohort size in which a pattern was detected was 7.7 embryos, and the smallest cohort size was 3. Of the fourteen cases, six had karyotyping that confirmed the suspected translocation in one member of the reproductive couple. One patient declined karyotyping, and five patients were lost to follow up. The remaining two cases were recently identified, and outcomes are pending. Therefore, in all cases in which the recommended karyotyping was performed, the suspected balanced translocation was confirmed. Our results show that PGS patterns of terminal segmental aneuploidy are highly predictive of a maternal or paternal reciprocal translocation. Future studies will develop criteria to also identify patterns predictive of Robertsonian translocations and inversions. We will standardize prediction criteria across each of our national and international laboratories and evaluate the frequency of chromosome rearrangement predictions in PGS cases. Confirming a maternal or paternal chromosome rearrangement can shed light on the cause of infertility and/or previous miscarriages. In addition, a newly identified translocation may have implications for past PGS cycles, would alter the estimated aneuploidy rate in future PGS cycles, and may affect the decision to use a gamete donor. Balanced translocations can be inherited and therefore may impact other family members in their reproductive years. Our data underscore the importance of follow up testing and counseling by a licensed genetic counselor when PGS predicts a balanced translocation.

OA-3 - Detection of a male translocation following an ovum donor preimplantation genetic screening cycle

OA-3 - Detection of a male translocation following an ovum donor preimplantation genetic screening cycle

The association between mitochondrial DNA content and implantation potential during IVF and preimplantation genetic screening cycles

The association between mitochondrial DNA content and implantation potential during IVF and preimplantation genetic screening cycles

Fresh vs frozen embryo transfer in frozen donor egg IVF and preimplantation genetic screening cycles

To evaluate whether freezing embryos, for a subsequent frozen embryo transfer (FET), would compromise the outcome in frozen donor egg IVF cycles when preimplantation genetic screening (PGS) was performed.

Intent to treat analysis of in vitro fertilization and preimplantation genetic screening versus expectant management in patients with recurrent pregnancy loss.

In an intent to treat analysis, are clinical outcomes improved in recurrent pregnancy loss (RPL) patients undergoing IVF and preimplantation genetic screening (PGS) compared with patients who are expectantly managed (EM)? Among all attempts at PGS or EM among RPL patients, clinical outcomes including pregnancy rate, live birth (LB) rate and clinical miscarriage (CM) rate were similar. The standard of care for management of patients with RPL is EM. Due to the prevalence of aneuploidy in CM, PGS has been proposed as an alternate strategy for reducing CM rates and improving LB rates. Retrospective cohort study of 300 RPL patients treated between 2009 and 2014. Among two academic fertility centers, 112 RPL patients desired PGS and 188 patients chose EM. Main outcomes measured were pregnancy rate and LB per attempt and CM rate per pregnancy. One attempt was defined as an IVF cycle followed by a fresh embryo transfer or a frozen embryo transfer (PGS group) and 6 months trying to conceive (EM group). In the IVF group, 168 retrievals were performed and 38 cycles canceled their planned PGS. Cycles in which PGS was intended but cancelled had a significantly lower LB rate (15 versus 36%, P = 0.01) and higher CM rate (50 versus 14%, P < 0.01) compared with cycles that completed PGS despite similar maternal ages. Of the 130 completed PGS cycles, 74% (n = 96) yielded at least one euploid embryo. Clinical pregnancy rate per euploid embryo transfer was 72% and LB rate per euploid embryo transfer was 57%. Among all attempts at PGS or EM, clinical outcomes were similar. Median time to pregnancy was 6.5 months in the PGS group and 3.0 months in the EM group. The largest limitation is the retrospective study design, in which patients who elected for IVF/PGS may have had different clinical prognoses than patients who elected for expectant management. In addition, the definition of one attempt at conception for PGS and EM groups was different between the groups and can introduce potential confounders. For example, it was not confirmed that patients in the EM group were trying to conceive for each month of the 6-month period. Success rates with PGS are limited by the high incidence of cycles that intend but cancel PGS or cycles that do not reach transfer. Counseling RPL patients on their treatment options should include not only success rates with PGS per euploid embryo transferred, but also LB rate per initiated PGS cycle. Furthermore, patients who express an urgency to conceive should be counseled that PGS may not accelerate time to conception. None. N/A. N/A. N/A.

Evaluation of 1100 couples with recurrent pregnancy loss using conventional cytogenetic, PGD, and PGS: hype or hope

Recurrent pregnancy loss (RPL) is an important clinical problem, mostly resulting from chromosomal or genetic defects, while in 30–60% of cases, it is idiopathic. The aim of this study is to evaluate the frequency and types of chromosomal abnormalities, also pre-implantation genetic diagnosis (PGD) and pre-implantation genetic screening (PGS) outcomes among Iranian couples with RPL. This retrospective study was conducted on 1100 Iranian couples (2200 individuals) with RPL referred to Royan Institute between 2008 and 2014. Karyotyping had been performed using standard cytogenetic techniques. PGD results of RPL patients with abnormal karyotypes and PGS results of RPL patients with normal karyotypes were also analyzed. The frequency of chromosomal abnormalities in these patients was 4.95%. Women demonstrated more abnormalities (6.82%) in comparison to men (3.09%). The successful rate of pregnancy after PGD and PGS was 52 and 18.64%, respectively. The observation of 4.95% chromosomal abnormalities among the patients with RPL could support this hypothesis that there is a direct relationship between chromosomal abnormalities and RPL. More than half of the patients who underwent PGD had successful pregnancy; therefore, this approach can improve the success rate of pregnancy in them. The results of PGS cycles showed that this technique could increase the live birth rate in RPL patients.

Clinical Pregnancy Rates after Elective versus Non-Elective Single Embryo Transfer in PGS Cycles

Objective: The objective of this study was to evaluate ongoing clinical pregnancy rates after elective single embryo transfer (eSET) versus non-elective single embryo transfer (non-elective SET) and compare them to ongoing pregnancy rates after double embryo transfer (DET) in IVF cycles with preimplantation genetic screening (PGS). Design: A retrospective study of SNP PGS outcome data from blastocysts biopsied on day 5 or day 6 was conducted to identify differences in ongoing clinical pregnancy rates between study groups. Settings: Large private IVF practice. Materials and methods: 676 cycles of IVF treatment (591 patients) with PGS between January 2013 and July 2016 followed by 658 FETs were included in the study (569 SETs and 89 double embryo transfers). 4102 embryos were vitrified after the trophectoderm biopsy, and selected embryos were subsequently thawed for a hormone replacement frozen embryo transfer (FET) cycle. 415 SETs were elective (two or more euploid embryos were available) and 154 SETs were non-elective (only one euploid embryo was available). Cumulative live birth rates were assessed by Kaplan-Meier function. Results: Our data demonstrated no statistically significant difference in clinical outcomes between the study groups: the ongoing pregnancy rate after an elective SET was 61.0% (253/415) and 53.3% (82/154) after a nonelective SET. Moreover, the ongoing pregnancy rates in a group of patients who had elective SET were not statistically different among different age groups (ongoing PR ranged from 42.3% to 56.1%). Similar results were obtained in a group of patients with non-elective SET (ongoing PR ranged from 56.1% to 66.1%). An increase in the total number of available euploid embryos from 2 to ≥ 5 embryos did not affect ongoing pregnancy rates after SET: 58.2% (53/91), 68.4% (67/98), 52.9% (36/68) and 61.4% (97/158), respectively, χ2=2.087, p=0.1486. Cumulative live birth rate after two consecutive SETs is equivalent to live birth rate after DET: 74.3% and 72.9%, respectively. Conclusion: Analysis of the data proved the effectiveness of single embryo transfers in IVF PGS cycles regardless of maternal age or total number of euploid embryos available for transfer. In order to maintain high ongoing pregnancy rates and reduce multiple gestation rates, single embryo transfer should be imperative in PGS cycles.

Aneuploidy screening by array comparative genomic hybridization improves success rates of in vitro fertilization: A multicenter Indian study.

OBJECTIVE:To evaluate the usefulness of preimplantation genetic screening (PGS) using array comparative genomic hybridization (aCGH) in the Indian population.MATERIALS AND METHODS:This is a retrospective, multicenter study including 235 PGS cycles following intracytoplasmic sperm injection performed at six different infertility centers from September 2013 to June 2015. Patients were divided as per maternal age in several groups (<35, 35–36, 37–38, 39–40, and >40 years) and as per indication for undergoing PGS. Indications for performing PGS were recurrent miscarriage, repetitive implantation failure, severe male factor, previous trisomic pregnancy, and advanced maternal age (≥35). Day 3 embryo biopsy was performed and analyzed by aCGH followed by day 5 embryo transfer in the same cycle or the following cycle. Outcomes such as pregnancy rates (PRs)/transfer, implantation rates, miscarriage rates, percentage of abnormal embryos, and number of embryos with more than one aneuploidy and chaotic patterns were recorded for all the treated subjects based on different age and indication groups.RESULTS:aCGH helped in identifying aneuploid embryos, thus leading to consistent implantation (range: 33.3%–42.9%) and PRs per transfer (range: 31.8%–54.9%) that were obtained for all the indications in all the age groups, after performing PGS.CONCLUSION:Aneuploidy is one of the major factors which affect embryo implantation. aCGH can be successfully employed for screening of aneuploid embryos. When euploid embryos are transferred, an increase in PRs can be achieved irrespective of the age or the indication.

Validation of next-generation sequencing for comprehensive chromosome screening of embryos

Massively parallel genome sequencing, also known as next-generation sequencing (NGS), is the latest approach for preimplantation genetic diagnosis. The purpose of this study was to determine whether NGS can accurately detect aneuploidy in human embryos. Low coverage genome sequencing was applied to trophectoderm biopsies of embryos at the blastocyst stage of development. Sensitivity and specificity of NGS was determined by comparison of results with a previously validated platform, array-comparative genomic hybridization (aCGH). In total, 156 samples (116 were blindly assessed) were tested: 40 samples were re-biopsies of blastocysts where the original biopsy specimen was previously tested for aCGH; four samples were re-biopsies of single blastomeres from embryos previously biopsied at the cleavage stage and tested using aCGH; 18 samples were single cells derived from well-characterized cell lines; 94 samples were whole-genome amplification products from embryo biopsies taken from previous preimplantation genetic screening cycles analysed using aCGH. Per embryo, NGS sensitivity was 100% (no false negatives), and 100% specificity (no false positives). Per chromosome, NGS concordance was 99.20%. With more improvement, NGS will allow the simultaneous diagnosis of single gene disorders and aneuploidy, and may have the potential to provide more detailed insight into other aspects of embryo viability.

Does early cleavage correlate with chromosome constitution in human preimplantation embryos?

IntroductionThe purpose of this study is to analyze the correlation between the occurrence of early cleavage and chromosome constitution of embryos from preimplantation genetic screening (PGS) and preimplantation genetic diagnosis (PGD). Material and methodsA total of 595 embryos from 96 cycles were included in this retrospective study. ResultsWhen clinical pregnancy rates per transfer were compared, statistically significant differences were observed between patients that had at least one early cleavage (ECpos) embryo and patients no EC (ECneg) (35.7% vs. 6.7%; p<.001). Statistically significant differences were found between EC, No PN and 2PN embryos at 26h, good embryo quality at day 2 (71.4%, 55.6% and 40.7%, respectively; p<.05) and in blastocyst rate (43.3% EC vs. no early cleavage embryos (NEC) 27.1%; p<.001) in PGS cycles. These differences were not found in the PGD group. Early-cleaved embryos exhibited less chromosome abnormalities than No PN and 2PN group in PGS (61%, 69.4% and 77.2%; p<.05) and differences in PGD group (69.8%, 76.2% and 66.7%; p<.05). DiscussionEarly cleavage has shown to correlate with embryo quality, with the capacity to develop up to blastocyst stage, as well as with euploid chromosome constitution.