Parameters of poor prognosis in preimplantation genetic testing for monogenic disorders.

STUDY QUESTION: What is the likelihood of success of a single cycle of preimplantation genetic testing for monogenic disorders (PGT-M), measured as the cumulative live birth rate (CLBR) and based on various patient demographics? SUMMARY ANSWER: For all women aged ≤40 years, the CLBR was at least 10% when the number of oocytes was ≥7 (range 10-30%) or was at least 5% when the number of oocytes was ≥3 (range 5-17%). WHAT IS KNOWN ALREADY: The number of oocytes is significantly associated with the number of embryos for genetic testing and the clinical outcome in PGT-M. Embryos diagnosed as affected or embryos that remain without diagnosis cannot be used for embryo transfer. The size of the group of embryos non-suitable for transfer varies between 25% and 81%, depending on the indication. Thus, PGT-M is more likely to be more severely impacted by suboptimal ovarian response, poor fertilization and suboptimal embryo development than conventional IVF/ICSI schemes without PGT. STUDY DESIGN, SIZE, DURATION: This was a single-centre retrospective comparative cohort study, of cycles between January 2011 and December 2015. A total number of 2265 PGT-M cycles were compared to 2833 conventional ICSI cycles. The principal aim of our study was the identification of the parameters of poor CLBR in couples undergoing PGT-M using multiplex short tandem repeat (STR) markers on blastomere biopsy DNA. The secondary aim was to compare the parameters of poor CLBR of the PGT-M population to those of couples undergoing ICSI without PGT. PARTICIPANTS/MATERIALS, SETTING, METHODS: The baseline characteristics of the PGT-M group were compared to the conventional ICSI group. A multiple regression analysis was applied to account for the following potential confounding factors: female age, number of previous ART cycles, number of oocytes/suitable embryos for transfer and dosage of gonadotrophins used for ovarian stimulation. MAIN RESULTS AND THE ROLE OF CHANCE: The PGT-M group was younger (female age 32.0 vs 34.5 years), had a higher number of previous ART cycles (1.1 vs 0.9 cycles) and used more gonadotrophins (2367 vs 1984 IU). Per cycle, the PGT-M group had more retrieved oocytes (11.8 vs 8.3 oocytes), fewer suitable embryos for transfer (1.7 vs 2.8 embryos) and a lower CLBR (29.4% vs 35.0%). Multiple regression analysis showed that the CLBR in the PGT-M group was significantly influenced by female age, the number of previous ART cycles, the number of oocytes and the dose of ovarian stimulation. In both groups, the predicted CLBR increased with increasing numbers of oocytes and suitable embryos. At least two retrieved oocytes or one embryo per single PGT-M cycle could confer an estimated CLBR above 10%. By assessing female age and the number of retrieved oocytes together, it was shown that for all women aged ≤40 years, the predicted CLBR per single PGT-M cycle was ≥10% when the number of oocytes was ≥7 or was ≥5% when the number of oocytes was ≥3. LIMITATIONS, REASONS FOR CAUTION: Despite the large sample size, the findings are confined by limited confounder adjustment and the lack of specific PGT-M comparators. WIDER IMPLICATIONS OF THE FINDINGS: This study aimed to describe the likelihood of success of PGT-M treatment, measured as CLBR, based on various patient demographics. In a PGT-M program, couples need to be informed of the prognosis more specifically when it is futile. The table of predicted CLBRs presented in this study is a useful tool in counselling PGT-M couples for making reproductive choices. STUDY FUNDING/COMPETING INTEREST(S): No funding was required and there are no competing interests. TRIAL REGISTRATION NUMBER: N/A.

Preimplantation genetic testing with HLA matching: from counseling to birth and beyond.

Preimplantation genetic testing-human leukocyte antigen '(PGT-HLA) only' refers to the HLA typing of single or few cells biopsied from in vitro fertilized preimplantation embryos. The aim of the procedure is to establish a pregnancy, in which the fetus is HLA compatible with an affected sibling in need of a hematopoietic stem cell transplantation (HSCT). During PGT-M-HLA, the identification of a HLA-compatible embryo is combined with the detection of mutation(s) underlying immunodeficiencies and hemoglobinopathies. We report a combined retrospective and prospective cohort analysis of PGT-(M-)HLA procedures carried out from 1998 until 2017, with follow-up of transplantations to 2019. During the study period, 234 couples from 22 countries were invited for a multidisciplinary consultation. Two couples were rejected and 70 couples declined (various reasons), leaving 162 couples for which 414 clinical cycles were carried out. Cleavage stage biopsy followed by single-cell multiplex PCR for short tandem repeat-based haplotyping was applied in most cases (98.7%). The diagnostic efficiency was high (94.8%) but only 16.5% of the embryos was genetically suitable for transfer. Fresh and frozen-thawed embryo transfer resulted in 67 clinical pregnancies, 63 deliveries, and 74 live births, of which 60 children were HLA compatible. This yielded a live birth delivery rate of 30.3% per transfer. Information on neonatal characteristics of the matching PGT-(M-)HLA children showed reassuring outcomes. So far, HSCT was carried out successfully for 25 out of 26 cases. In conclusion, our data show that PGT-(M-)HLA is a valuable procedure: the high complexity and limited delivery rate are balanced by the successful HSCT outcome and the positive impact on families.

Factors influencing the clinical outcome of preimplantation genetic testing for polycystic kidney disease.

STUDY QUESTION: What are the factors influencing the success rate for couples undergoing preimplantation genetic testing (PGT) for polycystic kidney disease (PKD)? SUMMARY ANSWER: In our study cohort, the live birth delivery rate is significantly associated with female age while the male infertility accompanying autosomal dominant PKD (ADPKD) does not substantially affect the clinical outcome. WHAT IS KNOWN ALREADY: While women with ADPKD have no specific fertility problems, male ADPKD patients may present with reproductive system abnormalities and infertility. STUDY DESIGN, SIZE, DURATION: This retrospective cohort study involves 91 PGT cycles for PKD for 43 couples (33 couples for PKD1, 2 couples for PKD2 and 8 couples for autosomal recessive PKD (ARPKD)) from January 2005 until December 2016 with follow-up of transfers until end of 2017. PARTICIPANTS/MATERIALS, SETTING, METHODS: Sixteen single-cell clinical tests for PKD based on multiplex PCR of short tandem repeat markers, with or without a specific mutation were developed and applied for diagnosis of 584 Day 3 cleavage stage embryos. In 18 couples, the male partner was affected with ADPKD (=Group A) and 12 of them had a documented infertility status. Group A underwent 52 cycles to oocyte retrieval. For 18 other couples, the female partner was affected with ADPKD (=Group B) and four male partners from this group had a documented history of infertility. This group underwent 31 cycles to OR. MAIN RESULTS AND THE ROLE OF CHANCE: Genetic analysis resulted in 545 embryos (93.3%) with a diagnosis, of which 215 (36.8%) were genetically transferable. Transfer of 74 embryos in 53 fresh cycles and of 34 cryopreserved embryos in 33 frozen-warmed embryo transfer cycles resulted in a live birth delivery rate of 38.4% per transfer with 31 singleton live births, two twin live births and one ongoing pregnancy. The observed cumulative delivery rate was 57.8% per couple after five treatment cycles. Thirty cryopreserved embryos still remain available for transfer. The clinical pregnancy rate per transfer (fresh + frozen; 45.9% in group A versus 60.0% in group B, P < 0.05) and the live birth delivery rate per transfer (fresh + frozen; 27.0% in group A versus 42.9% in group B, P < 0.05) was significantly lower for couples with the male partner affected with ADPKD compared with couples with the female partner affected with ADPKD. However, a multivariate logistic regression analysis showed that only female age was associated with live birth delivery rate (odds ratio = 0.87; 95% CI: 0.77-0.99; P = 0.032). LIMITATIONS, REASONS FOR CAUTION: This study is based on retrospective data from a single centre with Day 3 one-cell and two-cell biopsy. Further analysis of a larger cohort of PKD patients undergoing PGT is required to determine the impact of male infertility associated with ADPKD on the cumulative results. WIDER IMPLICATIONS OF THE FINDINGS: Knowledge about factors affecting the clinical outcome after PGT can be a valuable tool for physicians to counsel PKD patients about their reproductive options. Males affected with ADPKD who suffer from infertility should be advised to seek treatment in time to improve their chances of conceiving a child. STUDY FUNDING/COMPETING INTEREST(S): No funding was obtained. There are no competing interests to declare. TRIAL REGISTRATION NUMBER: Not applicable.

Dissociation between MK-801- and captivity-induced stereotypies in bank voles.

Pharmacologically induced stereotypies (PHIS) following dopamine agonists and, more recently, the non-competitive NMDA antagonist dizocilpine (MK-801), are used to study human psychopathology and for screening potential neuroleptic drugs. On the other hand, bank voles (Clethrionomys glareolus) spontaneously develop stereotyped jumping in barren cages, already before the age of 1 month (= captivity-induced stereotypies or CIS). Large interindividual differences in the level of jumping exist. In this study, the effect of MK-801 on various behaviours of bank voles, and in particular the relationship between CIS and PHIS, was investigated by repeated administration of MK-801 to stereotyping (ST) and non-stereotyping (NST) voles. The animals received nine daily s.c. injections of, respectively, saline and 0.3 mg/kg MK-801, with a 48-h break between both treatments. Their behaviour was visually recorded every 4 days. The results showed that jumping was neither evoked in NST, nor intensified in ST. Instead, in both ST and NST, PHIS consisting of intensive sniffing and locomotor stereotypy characterised by running in unidirectional circles were elicited. Furthermore, ST showed behavioural sensitisation for locomotor stereotypy, while in NST intensive sniffing was progressively enhanced. These results suggest that CIS and PHIS induced by MK-801 in bank voles are regulated, at least in part, by different neuronal mechanisms and that ST and NST could be predisposed to develop more easily one given PHIS than the other.