Reproductive hormones of ICSI-conceived young adult men: the first results.

STUDY QUESTION: Are reproductive hormone levels (FSH, LH, inhibin B and testosterone) in male offspring conceived by ICSI because of male infertility comparable with those from peers born after spontaneous conception? SUMMARY ANSWER: In this cohort of 54 young men conceived by ICSI because of male-factor infertility, mean and median reproductive hormone levels were found to be comparable with results from spontaneously conceived peers, but ICSI-conceived men were more likely to have low inhibin B (<10th percentile) and high FSH (>90th percentile) levels. WHAT IS KNOWN ALREADY: Since the worldwide oldest ICSI offspring have recently reached young adulthood, their reproductive health can now be investigated. This typically involves semen analysis and a hormonal profiling including the measurement of FSH, LH, inhibin B and testosterone. Circulating levels of FSH and inhibin B are generally known as markers of the exocrine function of the testis, i.e. spermatogenesis, while LH and testosterone reflect its endocrine function. We have previously observed a normal pubertal development and comparable levels of inhibin B and testosterone among pubertal ICSI boys when compared to spontaneously conceived peers. However, at present, information on the gonadal function of ICSI offspring in adulthood is still lacking. STUDY DESIGN, SIZE, DURATION: This study, conducted between March 2013 and April 2016 at the UZ Brussel, is part of a larger follow-up project focusing on reproductive and metabolic health of young adults between 18 and 22 years and conceived after ICSI because of male infertility. The ICSI men are part of a longitudinally followed cohort while the spontaneously conceived controls were recruited cross-sectionally. PARTICIPANTS/MATERIALS, SETTING, METHODS: Results of a single fasting blood sample from 54 young adult ICSI men were compared to that of 57 spontaneously conceived peers. Reproductive hormone analysis involved FSH, LH, testosterone and inhibin B measurement. Furthermore, the association between their reproductive hormones and their sperm parameters was examined. Data were analyzed by multiple linear and logistic regression adjusted for covariates. MAIN RESULTS AND THE ROLE OF CHANCE: ICSI men had comparable mean levels of FSH, LH, testosterone and inhibin B in comparison to spontaneously conceived counterparts, even after adjustment for confounders, such as age, BMI and season. Young ICSI-conceived men were more likely to have inhibin B levels below the 10th percentile (<125.2 ng/l; Adjusted Odds Ratio (AOR) 4.0; 95% CI: 0.9-18.4; P = 0.07) compared with spontaneously conceived peers and were more likely to have FSH levels above the 90th percentile (>5.5 IU/L; AOR 3.3; 95% CI: 0.9-11.9; P = 0.06) compared with spontaneously conceived peers, but neither difference reached statistical significance. FSH, LH and inhibin B, but not testosterone, levels were significantly associated with sperm concentration and total sperm count. LIMITATIONS, REASONS FOR CAUTION: The main limitation is the small study population. Furthermore, the results of this study should be interpreted according to the background of the participants: all subjects in our study group were conceived by ICSI because of severe male infertility and hence the results cannot be generalized to all ICSI offspring because the indications for performing ICSI have since been widened. WIDER IMPLICATIONS OF THE FINDINGS: These first results in a small group of ICSI men show reassuring reproductive hormonal levels. However, larger studies are required to confirm our results. Since inhibin B and FSH are consistently correlated with semen characteristics, we would suggest that the reproductive status of young adults conceived by ICSI is explored with a hormonal assessment given its easier acceptance compared to semen sampling. STUDY FUNDING/COMPETING INTERESTS: This study was supported by Methusalem grants and by grants from Wetenschappelijk Fonds Willy Gepts, all issued by the Vrije Universiteit Brussel (VUB). A grant from the Belgian Society for Pediatric Endocrinology and Diabetology was received for this project. All co-authors, except M.B. and H.T., declare no conflict of interest. M.B. has received consultancy fees from MSD, Serono Symposia and Merck. The Universitair Ziekenhuis Brussel (UZ Brussel) and the Centre for Medical Genetics have received several educational grants from IBSA, Ferring, Organon, Shering-Plough, Merck for establishing the database for follow-up research and organizing the data collection. The institution of HT receives research grants from the 'Research Fund of Flanders' (FWO), an unconditional grant from Ferring for research on testicular stem cells and research grants from Ferring, Merck, MSD, Roche, Besins, Goodlife and Cook for several research projects in female infertility. H.T. has received consultancy fees from Finox, Abbott and ObsEva for research projects in female infertility. TRIAL REGISTRATION NUMBER: N/A.

In vitro fertilization with single blastocyst-stage versus single cleavage-stage embryos.

BACKGROUND: Single-embryo transfer has been recommended to reduce the incidence of multiple gestations when in vitro fertilization is performed in women under 36 years of age. We designed a prospective, randomized, controlled trial to determine whether there were any differences in the rates of pregnancy and delivery between women undergoing transfer of a single cleavage-stage (day 3) embryo and those undergoing transfer of a single blastocyst-stage (day 5) embryo. METHODS: We studied 351 infertile women under 36 years of age who were randomly assigned to undergo transfer of either a single cleavage-stage embryo (176 patients) or a single blastocyst-stage embryo (175 patients). Multifollicular ovarian stimulation was performed with a gonadotropin-releasing hormone antagonist and recombinant follicle-stimulating hormone. RESULTS: The study was terminated early after a prespecified interim analysis (which included 50 percent of the planned number of patients) found a higher rate of pregnancy among women undergoing transfer of a single blastocyst-stage embryo (P=0.02). The rate of delivery was also significantly higher in this group than in the group undergoing transfer of a single cleavage-stage embryo (32.0 percent vs. 21.6 percent; relative risk, 1.48; 95 percent confidence interval, 1.04 to 2.11). Two multiple births occurred, both of monozygotic twins, both of which were in the group undergoing transfer of a single cleavage-stage embryo. CONCLUSIONS: These findings support the transfer of a single blastocyst-stage (day 5) embryo in infertile women under 36 years of age.

Diagnostic efficiency, embryonic development and clinical outcome after the biopsy of one or two blastomeres for preimplantation genetic diagnosis.

BACKGROUND: Preimplantation genetic diagnosis or screening (PGD, PGS) involves embryo biopsy on Day 3. Opting for one- or two-cell biopsy is a balance between the lowest risk for misdiagnosis on the one hand and the highest chance for a pregnancy on the other hand. METHODS: A prospective controlled trial was designed and 592 ICSI cycles were randomly assigned to the one-cell (group I) or the two-cell group (group II). Primary outcomes were diagnostic efficiency and embryonic development to delivery with live birth (analysed by cycle). The false-positive rate for the PCR cycles is presented as a secondary outcome (analysed by embryo). RESULTS: A strong significant correlation was observed between embryonic developmental stage on Day 3 and post-biopsy in vitro development on Day 5 (P < 0.0001). The influence of the intervention on Day 3 was less significant (P = 0.007): the biopsy of one cell is less invasive than the biopsy of two cells. PCR diagnostic efficiency was 88.6% in group I and 96.4% in group II (P = 0.008). For the fluorescence in situ hybridization (FISH) PGD cycles no significant difference in efficiency was obtained (98.2 and 97.5% in group I and II, respectively). Similar delivery rates with live birth per started cycle were obtained [58/287 or 20.2% in group I versus 52/303 or 17.2% in group II, P = 0.358; the absolute risk reduction = 3.05%; 95% confidence interval (CI): -3.24, 9.34]. Post-PGD PCR reanalysis showed six false positives in 97 embryos (6.2%) in group II and none in group I (91 embryos reanalysed). No false negatives were found. CONCLUSIONS: While removal of two blastomeres decreases the likelihood of blastocyst formation, compared with removal of one blastomere, Day 3 in vitro developmental stage is a stronger predictor for Day 5 developmental potential than the removal of one or two cells. The biopsy of only one cell significantly lowers the efficiency of a PCR-based diagnosis, whereas the efficiency of the FISH PGD procedure remains similar whether one or two cells are removed. Delivery rates with live birth per started cycle were not significantly different.

Efficient differentiation of human embryonic stem cells into a homogeneous population of osteoprogenitor-like cells.

The use of human embryonic stem cells (hESC) in both research and therapeutic applications requires relatively large homogeneous populations of differentiated cells. The differentiation of three hESC lines into highly homogeneous populations of osteoprogenitor-like (hESC-OPL) cells is reported here. These cells could be expanded in a defined culture system for more than 18 passages, and showed a fibroblast-like morphology and a normal stable karyotype. The cells were strongly positive for the same antigenic markers as mesenchymal stem cells but negative for markers of haematopoetic stem cells. The hESC-OPL cells were able to differentiate into the osteogenic, but not into the chondrogenic or adipogenic, lineage and were positive for markers of early stages of osteogenic differentiation. When cultured in the presence of osteogenic supplements, the cells indicated the capacity to achieve, under inductive conditions, a mature osteoblast phenotype. The differentiation protocol is based on a monolayer approach, and does not require any exogenous factors other than fetal calf serum, or coculture systems of animal or human origin. This method is likely to be amenable to large-scale production of homogeneous osteoprogenitor-like cells and thus overcomes one of the major problems of differentiation of hESC, with important relevance for further cell therapy studies.

Methylation analysis of KvDMR1 in human oocytes.

Recently, several reports have been published that showed a higher incidence of assisted reproductive technologies (ART) in patients with Beckwith-Wiedemann syndrome compared with the general population, and in most of these patients, aberrant methylation imprints of KvDMR1 have been found. This has led to the concern that ART might increase the incidence of imprinting syndromes such as Beckwith-Wiedemann syndrome. Not much is known on environmental or genetic factors that may interfere with the processes of imprint maintenance or resetting. A methylation analysis of KvDMR1 was performed in human oocytes at different stages of nuclear maturity and in sperm cells. The results indicate that the maternal methylation imprints were already established at the germinal vesicle stage, whereas all sperm cells were unmethylated, thereby showing that the KvDMR1 carries a germline methylation imprint. For one of the oocytes analysed, an unmethylated pattern was found, which highlights the need for further molecular studies that consider the safety of ART.

Single-cell chromosomal imbalances detection by array CGH.

Genomic imbalances are a major cause of constitutional and acquired disorders. Therefore, aneuploidy screening has become the cornerstone of preimplantation, prenatal and postnatal genetic diagnosis, as well as a routine aspect of the diagnostic workup of many acquired disorders. Recently, array comparative genomic hybridization (array CGH) has been introduced as a rapid and high-resolution method for the detection of both benign and disease-causing genomic copy-number variations. Until now, array CGH has been performed using a significant quantity of DNA derived from a pool of cells. Here, we present an array CGH method that accurately detects chromosomal imbalances from a single lymphoblast, fibroblast and blastomere within a single day. Trisomy 13, 18, 21 and monosomy X, as well as normal ploidy levels of all other chromosomes, were accurately determined from single fibroblasts. Moreover, we showed that a segmental deletion as small as 34 Mb could be detected. Finally, we demonstrated the possibility to detect aneuploidies in single blastomeres derived from preimplantation embryos. This technique offers new possibilities for genetic analysis of single cells in general and opens the route towards aneuploidy screening and detection of unbalanced translocations in preimplantation embryos in particular.

Clinical outcome of preimplantation genetic diagnosis for cystic fibrosis: the Brussels' experience.

Preimplantation genetic diagnosis is an alternative for prenatal diagnosis that makes it possible to perform the diagnosis of a chromosomal or monogenic disorder at the preimplantation embryo level. Cystic fibrosis is one of the monogenic diseases for which PGD can be performed. In this study, we looked at the requests and PGD cycles for this particular disorder over an 11-year period. Sixty-eight percent of the requests eventually led to at least one complete PGD cycle. In 80% of the cycles, an embryo transfer was performed and an ongoing pregnancy was obtained in 22.2% of the cycles with oocyte retrieval. After embryo transfer, a couple had 27.8% chance of giving birth to a liveborn child. No misdiagnosis was recorded. The rate of perinatal deaths/stillborn children was relatively high, but no excess of major congenital anomalies was observed in the surviving children.

Methylation analysis of the intergenic differentially methylated region of DLK1-GTL2 in human.

Imprinting is a non-Mendelian form of inheritance where epigenetic modifications control mono-allelic expression depending on the parental origin. Methylation of CpG-dinucleotides at differentially methylated regions (DMRs) is one of the best-studied mechanisms directing expression to one specific parental allele. We studied the methylation patterns of the intergenic (IG)-DMR of DLK1 and GTL2. The methylation marks of the IG-DMR were analysed in human gametes, preimplantation embryos, amniocytes and blood of babies born after intracytoplasmic sperm injection (ICSI) and blood from adults using a bisulphite sequencing technique. In oocytes, the IG-DMR was mainly unmethylated while in sperm cells a generally methylated pattern was detected. This germ-line specific methylation mark was maintained in the preimplantation embryos until the second cleavage stage. Afterwards in the preimplantation embryos, intermediate methylation patterns (26-74% methylation) occurred, which may point to relaxation of the imprints. Intermediate patterns were also present in amniocytes, blood from ICSI babies and adults. We hypothesise that in the early cleavage stage embryo a strict differential methylation pattern is needed for the correct imprint establishment of surrounding imprinted genes. Once correct imprinting of the involved gene(s) is acquired, a more relaxed state of the IG-region is allowed.

Developmental stage on day-5 and fragmentation rate on day-3 can influence the implantation potential of top-quality blastocysts in IVF cycles with single embryo transfer.

BACKGROUND: In IVF-ICSI cycles with single embryo transfer (SET), embryo selection for transfer is of crucial importance. The present study aimed to define which embryo parameters might be related to the implantation potential of advanced blastocysts. METHODS: Overall, in 203 cycles with SET, developmental characteristics of 93 implanted (group A) and 110 non-implanted (group B) advanced blastocysts of good quality were compared. The following developmental parameters were assessed in the two groups: normal fertilization, developmental stage on day 5, number of blastomeres on day 2 and on day 3, fragmentation rate on day 3, compaction on day 4 and cleavage pattern on day 2 and day 3. RESULTS: Expanded blastocysts compared to full blastocysts have higher implantation potential (56.5% vs. 29.3%, p < 0.05). In group B, a higher proportion of advanced blastocysts showed between 10% and 50% anucleated fragments on day 3 than in group A (23.6 vs 11.8, P = 0.03). Advanced blastocysts with >10-50% fragments on day 3 showed a significant lower implantation (29.7%) than those with < or = 10%fragments (49.4%, P = 0.03). All the other parameters analysed were comparable for the two groups. CONCLUSION: Developmental stage on day 5 and fragmentation rate on day 3 were related to the implantation potential of advanced blastocysts and should also be taken into account in the selection of the best advanced blastocyst for transfer.

Human embryo research in Belgium: an overview.

OBJECTIVE: To present an overview of the numbers and types of human embryos used in research projects in Belgium from 2007 to 2015. DESIGN: Analysis of all research proposals approved by the Federal Commission for Medical and Scientific Research on Embryos In Vitro. SETTING: Not applicable. PATIENT(S): Not applicable. MAIN OUTCOME MEASURE(S): Number of embryos used for research, number of embryos created for research, and areas of embryo research. RESULT(S): Since 2007, 15,811 embryos were used for 36 research projects. In total, 10,492 (66%) fresh supernumerary embryos (unfit for transfer or freezing) were used, 4,083 (26%) frozen supernumerary embryos (donated by parents whose child wish was completed or abandoned), and 1,236 (8%) embryos created for research. Most projects focused on research into embryo development. Fresh supernumerary embryos were mainly used for human embryonic stem cell (hESC) research. Frozen supernumerary embryos were almost exclusively used for research into embryo development and for hESC research. Embryos created for research were used for research into embryo development, oocyte research, research into cryopreservation of oocytes, and hESC research. CONCLUSION(S): Having concrete data on embryo research is crucial for an informed debate. Moreover, these data are necessary to find out trends in research such as the numbers of embryos needed and the areas of research. Data collection requires a sufficiently clear definition of "research" and "embryo." These conceptual questions frequently reveal lack of clarity in legislation.

Possible role of USP26 in patients with severely impaired spermatogenesis.

The ubiquitin-specific protease 26 (USP26) gene is an X-linked gene specifically expressed in testis tissue. This gene is therefore a potential infertility gene. In order to analyse its possible involvement in spermatogenesis and infertility, 42 patients with Sertoli cell-only syndrome were analysed for mutations in this gene. We found four patients with exactly the same three changes of the nucleotide and therefore also amino acid sequence. These patients showed 370-371insACA, 494T>C and 1423C>T causing T123-124ins, L165S and H475Y, respectively. These changes were not found in 10 control samples. Furthermore, two polymorphisms were observed which do not alter the amino-acid sequence. A restriction analysis that can make a distinction between a T and a C, at position 494, was set up in order to examine more patient and control samples. Another 69 patients with Sertoli cell-only syndrome, 32 patients with maturation arrest and 142 control samples were analysed using this method. None of the control samples or patients with maturation arrest featured the change at position 494. However, four more patients with Sertoli cell-only syndrome were identified with the three alterations. The frequency of alterations in this group is therefore 7.2% (8/111). One of the patients had a deletion of the long arm of the Y chromosome, while another patient had a varicocoele. These results indicate that these alterations might be involved in male infertility or might increase the risk of male infertility.

Preimplantation genetic diagnosis.

Preimplantation genetic diagnosis (PGD) was introduced at the beginning of the 1990s as an alternative to prenatal diagnosis, to prevent termination of pregnancy in couples with a high risk for offspring affected by a sex-linked genetic disease. At that time, embryos obtained in vitro were tested to ascertain their sex, and only female embryos were transferred. Since then, techniques for genetic analysis at the single-cell level, involving assessment of first and second polar bodies from oocytes or blastomeres from cleavage-stage embryos, have evolved. Fluorescence in-situ hybridisation (FISH) has been introduced for the analysis of chromosomes and PCR for the analysis of genes in cases of monogenic diseases. In-vitro culture of embryos has also improved through the use of sequential media. Here, we provide an overview of indications for, and techniques used in, PGD, and discuss results obtained with the technique and outcomes of pregnancies. A brief review of new technologies is also included.