Preimplantation genetic testing and child health: a national register-based study.

STUDY QUESTION: Is preimplantation genetic testing (PGT) associated with adverse perinatal outcome and early childhood health? SUMMARY ANSWER: Children born after PGT had comparable perinatal outcomes to children born after IVF/ICSI and comparable findings regarding early childhood health. WHAT IS KNOWN ALREADY: PGT is offered to couples affected by monogenic disorders (PGT-M) or inherited chromosomal aberrations (PGT-SR), limiting the risk of transferring the disorder to the offspring. PGT, an invasive technique, requires genetic analysis of one or up to ten cells from the embryo and is combined with IVF or ICSI. Several studies, most of them small, have shown comparable results after PGT and IVF/ICSI concerning perinatal outcome. Only a few studies with limited samples have been published on PGT and childhood health. STUDY DESIGN, SIZE, DURATION: We performed a register-based study including all singletons born after PGT (n = 390) in Sweden during 1 January 1996-30 September 2019. Singletons born after PGT were compared with all singletons born after IVF/ICSI (n = 61 060) born during the same period of time and with a matched sample of singletons (n = 42 034) born after spontaneous conception selected from the Medical Birth Register. Perinatal outcomes, early childhood health, and maternal outcomes were compared between pregnancies after PGT and IVF/ICSI as well as between pregnancies after PGT and spontaneous conception. Primary outcomes were preterm birth (PTB) and low birthweight (LBW) whereas childhood morbidity was the secondary outcome. PARTICIPANTS/MATERIALS, SETTING, METHODS: Data on women who went through PGT and gave birth were obtained from the local databases at the two PGT centres in Sweden, whereas data on IVF treatment for the IVF/ICSI group were obtained from the national IVF registers. These data were then cross-linked to national health registers; the Medical Birth Register, the Patient Register, and the Cause of Death Register. Logistic multivariable regression analysis and Cox proportional hazards models were performed with adjustment for relevant confounders. MAIN RESULTS AND THE ROLE OF CHANCE: The mean follow-up time was 4.6 years for children born after PGT and 5.1 years for children born after spontaneous conception, whereas the mean follow-up time was 9.0 years for children born after IVF/ICSI. For perinatal outcomes, PTB occurred in 7.7% of children after PGT and in 7.3% of children after IVF/ICSI, whereas the rates were 4.9% and 5.2% for LBW (adjusted odds ratio (AOR) 1.22, 95% CI 0.82-1.81 and AOR 1.17, 95% CI 0.71-1.91, respectively). No differences were observed for birth defects. In comparison to spontaneous conception, children born after PGT had a higher risk for PTB (AOR 1.73, 95% CI 1.17-2.58). Regarding early childhood health, the absolute risk of asthma was 38/390 (9.7%) in children born after PGT and 6980/61 060 (11.4%) in children born after in IVF/ICSI, whereas the corresponding numbers were 34/390 (8.7%) and 7505/61 060 (12.3%) for allergic disorders. Following Cox proportional hazards models, no significant differences were found for these outcomes. Sepsis, hypothyroidism, attention deficit hyperactivity disorder, autism spectrum disorders, mental retardation, cerebral palsy, and epilepsy were diagnosed in a maximum of three PGT children. No PGT children died during the follow-up period. Regarding maternal outcomes, the rates of placenta praevia and caesarean delivery were significantly higher after PGT in comparison to spontaneous conception (AOR 6.46, 95% CI 3.38-12.37 and AOR 1.52, 95% CI 1.20-1.92, respectively), whereas no differences were seen comparing pregnancies after PGT and IVF/ICSI. LIMITATIONS, REASONS FOR CAUTION: The rather small sample size of children born after PGT made it impossible to adjust for all relevant confounders including fertilization method and culture duration. Moreover, the follow-up time was short for most of the children especially in the PGT group, probably lowering the absolute number of diagnoses in early childhood. WIDER IMPLICATIONS OF THE FINDINGS: The results are reassuring and indicate that the embryo biopsy itself has no adverse effect on the perinatal, early childhood, or maternal outcomes. Although the results are comparable to IVF/ICSI also regarding early childhood outcome, they should be taken with caution due to the low number of children with diagnoses and short follow-up time. Long-term follow-up studies on children born after PGT are scarce and should be conducted considering the invasiveness of the technique. STUDY FUNDING/COMPETING INTEREST(S): The study was financed by grants from the Swedish state under the agreement between the Swedish government and the county councils, the ALF-agreement (LUA/ALF 70940), the Board of National Specialised Medical Care at Sahlgrenska University Hospital and Hjalmar Svensson Research Foundation. There are no conflicts of interest to declare. TRIAL REGISTRATION NUMBER: N/A.

Preimplantation genetic testing practices in the Nordic countries.

INTRODUCTION: Preimplantation genetic testing (PGT) is growing in importance and volume internationally. International societies such as the European Society for Human Reproduction and Embryology compile international results and these data are published in scientific journals. We present the first compilation of practices, quality measuress and outcome data from Nordic clinics performing PGT. MATERIAL AND METHODS: We conducted a structured online survey of PGT practices in the Nordic countries to compare clinical and laboratory techniques, outcomes and quality measures applied in Nordic clinics. The survey was designed by the authors and answered by the authors and members of the study group. The outcome data represents results from 2018. Results and details were clarified through iteration with responding clinics while maintaining anonymity. Response rate in the study was 80%, with 8 of 10 clinics performing PGT responding. RESULTS: Most of the PGT cycles in the Nordic countries are funded through the public healthcare system with University Hospitals performing the majority of treatments, 716/848, or 84.4%, of oocyte retrievals in this dataset. The genetic analyses are in five cases performed by the affiliated local genetic laboratory, and the remaining three consult with large international private enterprise laboratories. Genetic counseling is widely used. Results in the Nordic clinics compare well with international data. Systematic quality control procedures are in place and the larger clinics and laboratories utilize ISO certification or accreditation in the quality management. Automatic witnessing with detailed electronic documentation of laboratory processes is not utilized in the responding clinics, although a majority uses manual witnessing procedures in the laboratory. The outcome after PGT in terms of clinical pregnancy per transfer is around 40% per embryo transfer and compares well with international data. CONCLUSIONS: Preimplantation genetic testing is organized in rather few clinics in the Nordic countries and most of them use local laboratories for genetic analyses of the biopsies. Laboratory procedures are largely in accordance with international guidelines and the outcome after PGT in terms of clinical pregnancy per transfer is comparable to results in international reports.

Comprehensive analysis of soluble RNAs in human embryo culture media and blastocoel fluid.

PURPOSE: miRNAs have been suggested as biomarkers of embryo viability; however, findings from preliminary studies are divergent. Furthermore, the presence of other types of small RNA molecules remains to be investigated. The purpose of this study was to perform a comprehensive analysis of small non-coding RNA levels in spent and unconditioned embryo culture media, along with miRNA levels in blastocoelic fluid samples from human embryos. METHODS: miRNAs in unconditioned culture medium from 3 different manufacturers, along with miRNA from day 5 conditioned culture medium, control medium, and corresponding blastocoel fluid from 10 human blastocysts were analyzed with array-based q-PCR analysis. Subsequently, deep sequencing of total and small RNA in day 5 spent culture medium from 5 human blastocysts and corresponding controls was performed. RESULTS: In spite of using state-of-the-art sensitive detection methods, no miRNAs were found to be reliably present in the spent culture medium or the blastocoel fluid. Ct values were above the recommended limit for detection in the array-based analysis, a finding that was confirmed by deep sequencing. The majority of miRNAs identified by deep sequencing were expressed in all samples including control media and seem to originate from sources other than conditioned IVF media. CONCLUSIONS: Our findings question the use of miRNAs as a reliable biomarker and highlight the need for a critical methodological approach in miRNA studies. Interestingly, tiRNA fragments appear to be overexpressed in conditioned IVF media samples and could potentially be a novel biomarker worthy of investigation.

Impaired body balance, fine motor function and hearing in women with Turner syndrome.

OBJECTIVE: Fractures are related to falling. Turner syndrome (TS) is associated with hypogonadism, osteoporosis and fractures and has been considered as a syndrome of early ageing. The aim was to study whether fine motor function (FM) and body balance (BB) were impaired and related to genotype, fractures, metabolic variables and hearing. DESIGN: Cross-sectional study. PATIENTS: TS women, n = 75, mean age 30 years (range 16-59) and treated with oestrogen hormone replacement therapy (HRT) at the out-patient clinic, Sahlgrenska University Hospital, Göteborg, Sweden, and 31 healthy controls, mean age 37 years (range 24-63). MEASUREMENTS: Six FM and eight BB tests with open and closed eyes, respectively, were done. Bone mineral density was estimated with Dual energy X-ray Absorptiometry. Presence/absence of fractures was noted, blood samples were taken and audiometry was done in the TS women. RESULTS: TS women had poorer FM (27.4 +/- 6.0 vs. 32.8 +/- 2.2; P < 0.0001) and BB (28.0 +/- 8.1 vs. 34.7 +/- 2.4; P < 0.0001) than controls. FM was poorer in TS women with hearing aids compared to those without (P < 0.05). FM and BB were negatively correlated with age, waist : hip ratio and positively correlated with hearing, and bone mineral density, and BB was negatively correlated with physical activity in TS women. BB correlated negatively with age in controls. FM, BB and hearing function were poorer in 45,X, nonmosaics, than in 45,X/46,XX, mosaics. CONCLUSIONS: FM and BB were poorer in adult TS women on HRT than in controls. Higher age, hearing impairment, osteoporosis, abdominal obesity, a sedentary lifestyle and the TS per se were strong determinants, and mosaicism mitigated both fine motor function and BB in TS.

Side differences in the degree of mosaicism of the buccal mucosa in Turner syndrome.

BACKGROUND: The aim was to investigate if there were any differences in the degree of mosaicism between the left- and right-hand sides of the buccal mucosa in women with Turner syndrome. METHODS: Buccal smears were taken on the left- and right-hand sides at the same time for genetic analyses with fluorescence in situ hybridization in women with Turner syndrome, n = 20; 10 with and 10 without mosaicism based on the blood karyotype, and one control. A difference in the degree of mosaicism ≥5% between the sides was considered as an actual difference and <5% as equivalent. RESULTS: Of 20, 10 (50%) had ≥ 5% difference in the degree of mosaicism between the left- and right-hand sides of the buccal mucosa. The mean difference was 9.1% and the median was 4.5%, range 1%-38%. The control with ordinary female karyotype had no side difference. CONCLUSION: There was an intraorganic mosaicism of the buccal mucosa with a side difference in the degree of mosaicism of up to 38% in women with Turner syndrome. When mosaicism is strongly suspected, but not confirmed by the blood karyotype, it is recommended that buccal smears from both sides of the oral cavity should be analyzed.

Elevated liver enzymes in Turner syndrome during a 5-year follow-up study.

OBJECTIVES: To study the prevalence and incidence of elevated liver enzymes and their relationship with body weight, metabolic factors and other diseases in Turner syndrome (TS). DESIGN: Five-year follow-up. PATIENTS: Women with TS (n = 218, mean age 33 +/- 13, range 16-71 years) from outpatient clinics at university hospitals in Sweden. MEASUREMENTS: Fasting blood samples for aspartate (AST) and alanine aminotransferase (ALT), bilirubin, alkaline phosphatase (ALP), gamma-glutamyl transferase (GT), viral hepatitis serology and hepatic auto-antibodies, vitamin B12, blood glucose, lipids and hormones. RESULTS: Seventy-nine subjects (36%) had one or more liver enzyme levels higher than the reference level, the most prevalent being GT. Karyotype 45,X was present in 51% of all TS women and in 48% of those with elevated liver enzymes. Body weight, body mass index (BMI), total cholesterol, triglycerides, and apolipoproteins A and B at start were higher in TS women with elevated liver enzymes than in TS women with normal levels. At 5 years, AST, ALT and GT were increased and another 23% of patients had developed elevated liver enzymes, that is, 59% in total (36% + 23%), while in 6%, the elevated liver enzymes had been normalized and all 6% also had lowered cholesterol levels. Multivariate analysis showed that GT was correlated with total cholesterol; P = 0.0032 at start and P = 0.0005 at 5 years, independently of other factors. Liver biopsy in six TS women showed one cholangitis, one hepatitis C, two steatosis and two normal biopsies. Withdrawal of oestrogen substitution did not influence the liver enzymes. CONCLUSIONS: Pathological liver enzymes were common in TS women, with a prevalence of 36% at 33 years of age, an annual incidence over 5 years of 3.4%. There was no relation to karyotype, alcohol, viral hepatitis, E(2) or autoimmunity, but a connection with total serum cholesterol.

Transplanting embryonic stem cells onto damaged human corneal endothelium.

AIM: To investigate whether human embryonic stem cells (hESCs) could be made to attach, grow and differentiate on a human Descemet's membrane (DM). METHODS: Spontaneously differentiated hESCs were transferred onto a human corneal button with the endothelial layer removed using ocular sticks. The cells were cultured on a DM for up to 15 d. The genetically engineered hESC line expressed green fluorescent protein, which facilitated identification during the culture experiments, tissue preparation, and analysis. To detect any differentiation into human corneal endothelial-like cells, we analysed the transplanted cells by immunohistochemistry using specific antibodies. RESULTS: We found transplanted cells form a single layer of cells with a hexagonal shape in the periphery of the DM. The majority of the cells were negative for octamer-binding transcription factor 4 but positive for paired box 6 protein, sodium potassium adenosine triphosphatase (NaKATPase), and Zona Occludens protein 1. In four of the 18 trials, the transplanted cells were found to express CK3, which indicates that the stem cells differentiated into corneal epithelial cells in these cases. CONCLUSION: It is possible to get cells originating from hESCs to become established on a human DM, where they grow and differentiate into corneal endothelial-like cells in vitro.

Clonal derivation and characterization of human embryonic stem cell lines.

Human embryonic stem cells (hESC) are isolated as clusters of cells from the inner cell mass of blastocysts and thus should formally be considered as heterogeneous cell populations. Homogenous hESC cultures can be obtained through subcloning. Here, we report the clonal derivation and characterization of two new hESC lines from the parental cell line SA002 and the previously clonally derived cell line AS034.1, respectively. The hESC line SA002 was recently reported to have an abnormal karyotype (trisomy 13), but within this population of cells we observed rare individual cells with an apparent normal karyotype. At a cloning efficiency of 5%, we established 33 subclones from SA002, out of which one had a diploid karyotype and this subline was designated SA002.5. From AS034.1 we established one reclone designated AS034.1.1 at a cloning efficiency of 0.1%. These two novel sublines express cell surface markers indicative of undifferentiated hESC (SSEA-3, SSEA-4, TRA-1-60, and TRA-1-81), Oct-4, alkaline phosphatase, and they display high telomerase activity. In addition, the cells are pluripotent and form derivatives of all three embryonic germ layers in vitro as well as in vivo. These results, together with the clonal character of SA002.5 and AS034.1.1 make these homogenous cell populations very useful for hESC based applications in drug development and toxicity testing. In addition, the combination of the parental trisomic hESC line SA002 and the diploid subclone SA002.5 provides a unique experimental system to study the molecular mechanisms underlying the pathologies associated with trisomy 13.

Hypothyroidism is common in turner syndrome: results of a five-year follow-up.

Turner syndrome (TS) is caused by a sex chromosome aberration. The aim was to study the prevalence and incidence of thyroid disease in adults with TS. Women with TS (n = 91; mean age, 37.7 +/- 11 yr) were compared with an age-matched female random population sample (n = 228). At baseline, 15 (16%) TS women were treated for hypothyroidism, and elevated serum TSH was found in another eight (9%). As a result, hypothyroidism was more common in women with TS (25%) than in controls (2%; P < 0.0001). Serum free T4 was lower (P = 0.02), and serum TSH was higher (P < 0.0001) in TS women than in age-matched controls. Of all TS women with hypothyroidism, 10 (43%) had an elevated thyroid peroxidase antibody titer vs. 15 (22%) of those without hypothyroidism (P < 0.05), evenly distributed between the karyotype 45,X and mosaicism. A high body mass index, but not a family history or blood lipids, was associated with hypothyroidism in TS. After the 5-yr follow-up, an additional 11 (16%) developed hypothyroidism, of whom four (36%) had elevated thyroid peroxidase. Altogether, 34 (37%) TS women had hypothyroidism after the 5-yr follow-up. Autoimmune hypothyroidism was common, with an annual incidence of 3.2% in TS. Thyroid function should be checked regularly in TS.

Human embryonic stem cells and chromosome stability.

The use of human embryonic stem cells (HESC) in research is increasing exponentially and HESC will certainly be of importance in biological, clinical and toxicological research for many years to come. Once established, HESC lines are expected to be chromosomally stable. However, our own experience of culturing HESC and some published reports indicate that HESC may show chromosomal instability while being cultured continuously in vitro. We conclude that the effects of different culture techniques and long-term culture on the chromosome stability of HESC still remain to be elucidated and we recommend regular analysis of the chromosome constitution in cell lines using traditional karyotyping, CGH, FISH and PCR. We also recommend freezing of HESC at low passage number and in larger batches after thawing and expansion in order to secure material in case mutations occur in the cell line at a later stage of culture.

The proportion of diploid 46,XX cells increases with time in women with Turner syndrome--a 10-year follow-up study.

In the normal population, loss of one of the sex chromosomes leading to monosomy (45,X) is a part of the aging process. In Turner syndrome (TS), the classic karyotype 45,X is found in up to 50% at birth, and others have a second cell line; mosaicism. The aim was to study if the chromosomal pattern in TS women changes over time. Fluorescence in situ hybridization was performed on buccal smear cells obtained twice, 10 years apart, from 42 women with TS aged 26-66 years (mean±standard deviation: 42.0±11.6). DNA probes specific for chromosomes X (DXZ1) and Y (DYZ3) were used and >100 cells were analyzed/patient. Nineteen women had monosomy (45,X) (<10% 46,XX), nine had 45,X/46,XX mosaicism, and 14 had iso, ring, or a marker chromosome at baseline. At 10 years, the percentage of diploid cells had increased in 29 of 42 women (69%), with an average increase of 5.7±13.0%. There was a positive correlation between age and % change in diploid 46,XX or 46,XY cells (r=0.38, p=0.023). This new finding might have relevance for the life expectancy in TS.

[Cloning techniques for mitochondrial diseases and prenatal diagnosis]. / Kloningstekniker för mitokondriellt nedärvda sjukdomar och fosterdiagnostik.

Disorders caused by mutation in the mitochondrial DNA are uncommon. Due to the special pattern of inheritance and of the variability of penetrance the options to affected couples to have healthy children are few. So far traditional prenatal diagnosis is of limited benefit. The problems may be overcome by oocyte donation. However, if the couple wants their own biological offspring, no good method is available today. We discuss ooplasmic and nuclear transfer as possible future options for these couples to have healthy biological children.

Transplantation of human embryonic stem cells onto a partially wounded human cornea in vitro.

PURPOSE: The aim of this study was to investigate whether cells originating from human embryonic stem cells (hESCs) could be successfully transplanted onto a partially wounded human cornea. A second aim was to study the ability of the transplanted cells to differentiate into corneal epithelial-like cells. METHODS: Spontaneously, differentiated hESCs were transplanted onto a human corneal button (without limbus) with the epithelial layer partially removed. The cells were cultured on Bowman's membrane for up to 9 days, and the culture dynamics documented in a time-lapse system. As the transplanted cells originated from a genetically engineered hESC line, they all expressed green fluorescent protein, which facilitated their identification during the culture experiments, tissue preparation and analysis. To detect any differentiation into human corneal epithelial-like cells, we analysed the transplanted cells by immunohistochemistry using antibodies specific for CK3, CK15 and PAX6. RESULTS: The transplanted cells established and expanded on Bowman's membrane, forming a 1-4 cell layer surrounded by host corneal epithelial cells. Expression of the corneal marker PAX6 appeared 3 days after transplantation, and after 6 days, the cells were expressing both PAX6 and CK3. CONCLUSION: This shows that it is possible to transplant cells originating from hESCs onto Bowman's membrane with the epithelial layer partially removed and to get these cells to establish, grow and differentiate into corneal epithelial-like cells in vitro.

Pregnancy rate and outcome in Swedish women with Turner syndrome.

Pregnancies occurred in 57 (12%) of 482 Swedish women with Turner syndrome with a liveborn rate of 54% in 124 pregnancies. Spontaneous pregnancies occurred in 40%, mainly in women with 45,X/46,XX mosaicism, and oocyte donation in 53% where miscarriages were less frequent, odds ratio = 0.43 (95% confidence interval 0.17-1.04).

Myofibroblasts in the normal conjunctival surface.

PURPOSE: To investigate the occurrence of myofibroblasts (MFBs) in the normal conjunctival surface and to evaluate any anatomical and time-related variations. METHODS: MFBs were screened among healthy individuals (35 eyes) by collecting impression cytology (IC) samples from the bulbar conjunctiva. A cohort of volunteers (12 eyes) was followed for 1 year by taking two to five imprints every month. MFBs were identified by immunohistochemical localization of the MFB marker alpha-smooth-muscle actin (alpha-SMA). RESULTS: Using a filter imprint technique, MFBs were found consistently in 94% of samples from the conjunctival surface of participating individuals. The overall MFB levels, expressed as percentage of all cells on the filter, were highest in March-May [mean 4.1%, standard deviation (SD) +/- 1.5] and lowest in December-February (mean 1.2%, SD +/- 0.5). The difference was statistically significant [p < 0.0005, Friedman test, one-way repeated measures analysis of variance (anova)]. Moreover, there was a clear divergence of MFB density between the nasal, temporal, superior and inferior bulbar conjunctiva (mean 1.7%, 1.9%, 22% and 9.7%, respectively). CONCLUSION: MFBs, known as a cellular constituent of granulation tissue in wound healing, occur in the normal conjunctival surface, which is a novel finding. Our results also show that MFB level follows a seasonal variation pattern in a temperate climate, increasing in April-September and decreasing in October-March. This variation might reflect a degree of a transient or ongoing state of tissue repair after conjunctival trauma or stress caused by exposure to environmental factors.

Donor and recipient endothelial cell population of the transplanted human cornea: a two-dimensional imaging study.

Purpose. To elucidate the pattern of donor and recipient endothelial cell populations in transplanted human corneas and determine the degree to which donor endothelial cells survive in the graft. Methods. Thirty-six corneal grafts were collected from recipients of opposite sex to the donor, at the time of retransplantation for various indications. Cells from the endothelial side of the grafts were harvested, preserving their relative location on the endothelium. Fluorescence in situ hybridization of the sex chromosomes enabled each cell to be identified as donor- or recipient-derived. Images of the graft endothelium were assembled, to depict the pattern of cell population of the graft, and the proportion of donor cells present was estimated. Results. Endothelial cells of donor origin were found in 26 of 36 grafts (72.2%)-in one case, up to 26 years after transplantation. The proportion of donor endothelium ranged from 2% to 99%; however, there was no significant correlation of this proportion with postoperative time (P = 0.19). The mean annual rate of donor cell loss correlated negatively with the time to graft failure by endothelial decompensation (P = 0.002). Endothelial images indicated a highly variable pattern of recipient cell repopulation of the graft. A tendency toward donor cell retention in transparent, successful grafts was noted; however, this feature alone was not a reliable indicator of long-term graft transparency. Conclusions. Two-dimensional imaging of the corneal graft endothelium revealed a variable pattern and extent of donor and recipient cell population, indicating the highly dynamic nature of the corneal endothelium after transplantation.

Survival of donor-derived cells in human corneal transplants.

PURPOSE: To determine the fate of donor epithelial, stromal, and endothelial cells after corneal transplantation in humans. METHODS: Fifty-two transplanted corneal buttons were explanted over a 2-year period from patients who required regrafting and had received corneas from donors of opposite sex. Fluorescence in situ hybridization of the sex chromosomes of the epithelial, stromal, and endothelial cells was performed in histologic sections prepared from each freshly explanted graft. Fluorescence microscopy was subsequently used to determine the origin of cells in the graft (donor or recipient) and to quantify the relative proportion of donor and recipient cells of each corneal cell type. RESULTS: As early as 3 months after transplantation, donor epithelial cells were completely replaced by recipient epithelium in all corneal buttons examined. Donor stromal and endothelial cells, however, were found in all 52 buttons, with 4% to 95% of stromal cells and 6% to 95% of endothelial cells being of donor origin. No significant correlation between donor cell proportion and the age of the graft could be found. Donor-derived cells were found in significant numbers up to 32 years after transplantation. Eight corneas in this study were transparent, compensated grafts, and a similar long-term survival of donor stromal and endothelial cells was found in these cases. CONCLUSIONS: Although donor epithelial cells are promptly replaced, a high proportion of donor stromal and endothelial cells can survive within the corneal transplant in the long-term. The proportion of surviving donor cells is highly variable; however, the source of this variability remains unknown.