Does additional hybridization also improve preimplantation genetic screening results?

Increased efficiency of preimplantation genetic diagnosis for infertility using “no result rescue”

O-138: Preimplantation genetic diagnosis (PGD) is indicated for recurrent miscarriage even in cycles producing five or fewer embryos

Thawing cryopreserved oocytes: genetic screening of thawed oocytes and ongoing pregnancy success rate

Detection of Mosaicism in Blastocyst using High Resolution Next Generation Sequencing Preimplantation Genetic Screening (hr-NGS)

Preimplantation genetic screening (PGS) for aneuploidy in embryos after in vitro fertilization (IVF) does not improve reproductive outcome in women over 35: a prospective controlled randomized study

Next-generation sequencing: challenges in reproductive genetics

Study question Does the selection of blastocysts for single embryo transfer, through the diagnosis of aneuploidy, improves the live birth rate in patients undergoing in vitro fertilization? Summary answer There seems to be no statistical difference in live birth rates between embryos with preimplantational genetic diagnosis (PGD) and those without. What is known already: Initial reports indicate that reproductive results improve after the selection of embryos to be transfer after performing a biopsy of the blastomeres, or trophectoderm cells, with the subsequent comprehensive analysis of the chromosomes. However, these results are now questioned. Reports in the literature are contrasting, so the real utility of selecting all embryos through comprehensive chromosome analysis calls for a more careful analysis that compares the risks, costs, and benefits of these techniques and their actual utility in reproductive results of patients treated with in vitro fertilization. Specifically results related to live birth rate. Study design, size, duration A systematic review of prospective studies evaluating live birth rate after embryo transfer of embryos selected by blastocyst biopsy for aneuploidy analysis compared with reproductive outcomes in embryo transfers of embryos selected morphologically, without biopsy nor screening for aneuploidies. Participants/materials, setting, methods A literature search was performed in PubMed, EmBase, and the Cochrane library (from January 2000 to december 2019). A cumulative meta-analysis and evaluation of heterogeneity was performed for the clinical pregnancy rate. The quality of the included studies was assessed using Cochrane’s Risk of Bias tool and ROBINS I for observational studies Main results and the role of chance Seven studies were included, three were randomized controlled trials and four were non-randomized studies of intervention (NRSI). The included studies were published between 2013 and 2019. For the preimplantational genetic diagnosis, three studies used array comparative genomic hybridization, three studies used next generation sequencing and only one study used qPCR. A total of 1638 patients were included, only two studies excluded patients with advanced maternal age (>35 years), two studies studied patients with recurrent implantation failure and three studies patients with recurrent pregnancy loss. Regarding the assisted reproduction techniques (ART), only studies where embryos where biopsied after day five for the genetic diagnosis where considered, most used ICSI and performed frozen-thawed transfer of up to two embryos, only one study allowed patients to be transferred with more than two embryos per cycle. Reproductive outcomes (live birth rate, miscarriage rate, clinical pregnancy) were extracted considering the events per embryo transfer and calculating the pooled odds ratios (OR) with 95% confidence intervals (95%CI) as our main outcome, sensitivity analyses will be performed using the events per cycles to assess the robustness of the effect estimate. Preliminary meta-analyses resulted in a pooled OR of 1.45 (95%CI 0.24–8.78) for NRSI and 1.34 (95%CI 0.85–2.11) for RCT. Limitations, reasons for caution The main limitation was the quantity of studies with acceptable methodology. This generated heterogeneity, hindering the evaluation of the true impact of PGD in ART outcomes. The use of events per embryo transfer as a main outcome could bias the results favoring PGD as less embryos are usually transferred. Wider implications of the findings: Our results show that there are too few studies with adequate methodology to generate a conclusion about the true benefit of PGD. However, a slight tendency favoring the reproductive outcomes of PGD was found. Trial registration number PROSPERO CRD42020198866

Deep impact: sequencing embryo biopsy specimens at increasing depth

Outcomes of trophectoderm biopsy on cryopreserved blastocysts: a case series

In both in vitro fertilisation (IVF) and intracytoplasmic sperm injection (ICSI), selection of the most competent embryo(s) for transfer is generally based on morphological criteria. However, many women fail to achieve a pregnancy after transfer of good quality embryos. One of the presumed causes is that such morphologically normal embryos show an abnormal number of chromosomes (aneuploidies). In preimplantation genetic screening (PGS), embryos are analysed for aneuploidies and only embryos that are euploid for the chromosomes tested are transferred. This technique has been suggested and used to improve pregnancy rates for the following indications: (i) advanced maternal age, (ii) repeated IVF failure, (iii) repeated miscarriage and (iv) testicular sperm extraction (TESE)-ICSI. Although PGS is used more and more often, its effectiveness is still unclear. To assess the effectiveness of PGS in terms of live births in women undergoing IVF or ICSI treatment. We searched the Cochrane Menstrual Disorders and Subfertility Group Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (Cochrane Library Issue 1, 2005), MEDLINE (1966 to present) and EMBASE (1980 to present) (searched March 2005) and reference lists of articles. We also contacted authors for providing additional data when necessary. Trials for all four suggested indications as mentioned above were sought. All relevant published randomised controlled trials were selected. They were eligible for inclusion if the comparison dealt with IVF/ICSI with PGS versus IVF/ICSI without PGS. Relevant data were extracted independently by two authors. All trials were screened and analysed according to predetermined quality criteria. Validity was assessed in terms of method of randomisation, completeness of follow-up, intention-to-treat analysis and presence or absence of blinding. The primary outcome measure was live birth rate per woman. Secondary outcome measures were the proportion of women reaching embryo transfer, mean number of embryos transferred per transfer, clinical pregnancy rate, multiple pregnancy rate, miscarriage rate, ongoing pregnancy rate, proportion of women reaching embryo transfer after cryopreservation and proportion of women whose child has a congenital malformation. Two randomised controlled trials met our predetermined eligibility criteria. These trials used PGS for advanced maternal age. The primary outcome of live birth rate per woman was not significantly different in the PGS and control groups, though data were only available from one study. The live birth rate was 11% (21 out of 199) in the PGS group, versus 15% (29 out of 190) in the control group (OR 0.65; 95% CI 0.36 to 1.19). For a control group rate of 15%, these data suggest a live birth rate using PGS of between 4% and 17%. Ongoing pregnancy rate was provided in both studies. This was not significantly different with a combined odds ratio of 0.64 (95% CI 0.37 to 1.09). For a control group rate of 20%, this suggests an ongoing pregnancy rate using PGS of between 8% and 21%. To date there is insufficient data to determine whether PGS is an effective intervention in IVF/ICSI for improving live birth rates. Available data on PGS for advanced maternal age showed no difference in live birth rate and ongoing pregnancy rate. However, only two randomised trials were found, of which one included only 39 patients. For both studies comments on their methodological quality can be made. Therefore more properly conducted randomised controlled trials are needed. Until such trials have been performed PGS should not be used in routine patient care.

Patient education and informed consent for preimplantation genetic diagnosis: Health literacy for genetics and assisted reproductive technology

Preimplantation genetic diagnosis (PGD) has been available for nearly 10 years, and this approach presently is practiced in 17 countries for an increasing number of indications. The few studies done suggest that PGD is most accepted by women who have previously had an affected pregnancy terminated. Because substantial investment is needed to set up a PGD program, for both equipment and highly trained personnel, an attempt was made to determine the level of demand for the procedure in the United Kingdom in a survey of patient interest groups, regional genetics centers, assisted conception units, and health authorities. Couples were sent a questionnaire to learn how aware they are of PGD technology. The conditions targeted for the survey included cystic fibrosis, thalassemia, retinitis pigmentosa, Duchenne muscular dystrophy, hemophilia, leukodystrophy, Huntington disease, and sickle cell anemia. More than 70 percent of the institutions surveyed and all patient interest groups responded to the questionnaire. In vitro fertilization units reported referring up to 156 cases annually, and genetics centers reported referring 52. Patient interest groups knew of another 48 referrals. Two-thirds of regional genetics centers were aware of PGD methods of diagnosing cystic fibrosis, but fewer knew of methods for diagnosing X chromosome–linked disorders or chromosomal translocations. About one-fourth of the centers still believe that accuracy and reliability are controversial issues. About one-fourth of in vitro fertilization units had referred couples for PGD, chiefly to detect cystic fibrosis. Eight of nine patient groups were aware of PGD, but only two knew which hospitals offer the procedure. A large majority of patient groups and one-third of genetic centers reported believing that inadequate information is available on PGD. Only 18 percent of the health authorities surveyed have a policy for PGD, and nearly two-thirds were unaware of the procedure. About three in four authorities did not know how the cost of a cycle of PGD compares with that of caring for an affected child. This survey in itself seems to have raised awareness of PGD. Contact with patient interest groups has been especially fruitful. It would seem that a lack of information about this practice has limited patient choices. Prenat Diagn 1999;19:1205–1208

The development of in vitro fertilization in the 1970s has revolutionized the treatment of infertility. In the US, 126 procedures are performed per million people each year. The ability to culture embryos in vitro has allowed the development of preimplantation genetic diagnosis (PGD). PGD is similar to the prenatal diagnosis used to screen for various genetic diseases before birth, but its advantage is that it allows the selection of certain embryos before their transfer back to the uterus and avoids selective pregnancy terminations. For women of advanced maternal age or couples with known genetic mutations, the ability to screen for embryos free of certain genetic mutations is reassuring. As with many medical interventions associated with human reproduction, however, PGD raises many ethical issues. Recently, PGD has been used in new ways, including: HLA typing so that the child's HLA profile matches that of a sick sibling and is thus available for stem cell transplantation; sex selection; and selection of affected embryos so that the child has the same minor disability as the parents (e.g., deafness). We explore the field of PGD with the director of a PGD laboratory, a bioethicist, and an attorney to understand their views on the ethics of PGD. As the director of a PGD laboratory, do you feel laboratories need to consider the moral/ethical and societal implications before developing a new PGD test? Richard T. Scott: The practice in a PGD laboratory is no different from any other area of medicine. Thoughtful and ethical decision-making is mandatory. Any controversial case is first evaluated by all the physicians and scientists in the program. Complex issues are dealt with by the entire team, with the ultimate responsibility falling on the director. We are always mindful that PGD laboratories are unique, in that they analyze embryo biopsies and produce …

Background: Preimplantation genetic diagnosis (PGD) is currently used for over 400 monogenic diseases. Some endocrine conditions that occur due to monogenic defects are either life threatening or can cause severe morbidities; thus, PGD may be an option to avoid the occurrence of such diseases. But a high cost and limited availability of licensed IVF centers can be a barrier for many patients who might otherwise benefit from PGD. Objective: To review the literature for endocrine monogenic disorders that have been prevented with PGD. Methods: An initial search in PubMed/Medline search was done to identify monogenic endocrine conditions using MeSH term “preimplantation diagnosis” and other searches using “preimplantation genetic diagnosis (PGD)”, plus “endocrine” or “monogenic” anywhere in the title or abstract. Studies were eligible for consideration if they included use of PGD for any known monogenic endocrine disease. Studies were omitted if the disease was non-endocrine or PGD was not used for embryo selection. Eleven articles (1999-2018) reported 15 cases using PGD for monogenic endocrine diseases. These were Congenital adrenal hyperplasia (n=2), X-linked adrenoleukodystrophy (n=2), Congenital lipoid adrenal hyperplasia (n=1), Persistent hyperinsulinemic hypoglycemia of infancy (n=4), Pseudohypoparathyroidism type 1a (n=1), Hypoparathyroidism-retardation-dysmorphism syndrome (n=2) and Multiple endocrine neoplasia types 1 (n=1) and 2a (n=2). Techniques used for PGD included PCR, whole genome amplification, FISH and more recently next generation sequencing. Clinical and outcome data of these cases were reviewed with respect to number of PGD cycles, successful pregnancy rates, live births and their genetic status. Results: Fifteen couples underwent 32 PGD cycles (ranging from 1-9 per couple), of which 17 cycles resulted in a pregnancy. Seven couples underwent a single PGD cycle. Four of these 7 couples had successful pregnancies each resulting in live births (all singletons), 1 couple was unable to achieve pregnancy, 1 chose to terminate the pregnancy as the karyotype detected a Turner fetus (45XO) and outcome data was not reported in one. The remaining 8 couples underwent multiple PGD cycles (2-9 per couple) and all had successful pregnancies in at least one cycle, resulting in 16 livebirths (6 singletons and 5 twins). Amongst the total live births (n=20), 60% were genetically unaffected for the tested monogenic disorder and 40% were carriers of the autosomal recessive gene mutation for which PGD was performed. Conclusion: Preimplantation genetic diagnosis may be a potential tool for preventing the inheritance of severe monogenic endocrine diseases in future generations. The current use of PGD in endocrine disorders is rare, but provides a promising option on a case by case basis provided the optimal resources are available.

Couples undergoing preimplantation genetic diagnosis (PGD) have a different background and set of treatment characteristics to couples undergoing regular IVF or ICSI. The aim of this study was to analyse the cumulative reproductive outcome of a large cohort of couples undergoing PGD in relation to a number of explanatory variables potentially affecting the prognosis. Prospective cohort study, Kaplan-Meier analysis was performed to estimate real (observed) and expected (calculated) cumulative delivery rates, and Cox proportional hazard regression analysis was used to assess the effect of age, number of cumulus oocyte complexes collected, fertility status, parity, genetic category and method of pituitary suppression. Between 1993 and 2005, 2753 unselected consecutive cycles of ICSI and PGD were carried out in 1498 couples. The cumulative observed delivery rate overall per couple with a maximum of six treatment cycles of ICSI and PGD performed was 29%. The expected cumulative delivery rate (max six cycles) overall was 62%. There were no significant differences in cumulative delivery rates between the different genetic categories (i.e. availability of transferable embryos after PGD of 50 or 75%, chromosomal translocations or aneuploidy screening). The cumulative reproductive outcome in this PGD cohort was also not significantly affected by the fertility status of the couple, their parity or the method of pituitary suppression. However, the age of the patient and the number of oocytes contributed significantly to the reproductive results. This prospective observational study demonstrates that age has a significantly negative effect on outcome of PGD, due to poor reproductive performance of female partners 40 years of age and older. The number of oocytes collected has a significant and independent effect. The other factors studied did not affect the cumulative reproductive outcome in this PGD cohort.