Anthropometric measurements of term singletons at 6 years of age born from fresh and frozen embryo transfer: A multicenter prospective study in Japan.

Purpose: The purpose of this study is to compare anthropometric measurements between term singletons conceived via fresh embryo transfer (FreET) and frozen embryo transfer (FET) and those born via natural conception (NC) or fertility treatments milder than assisted reproductive technology (non-ART) at 6 years of age. Methods: A total of 8149 children were enrolled, and questionnaires about anthropometric measures (weight, height, BMI) were addressed to parents, when the children were 1.5, 3, and 6 years of age. A total of 3299 term singletons were enrolled at birth: 533, 476, 916, and 1374 in the NC, non-ART, FreET, and FET groups, respectively. Results: A total of 1635 term singletons (290, 176, 467, and 702 in the NC, non-ART, FreET, and FET groups respectively) were enrolled until 6 years of age (follow-up rate, approximately 50%). When non-ART group was used as control, the FreET children were 1.0 cm taller than the non-ART children at 6 years of age, after adjusting for confounding factors. However, no differences were observed in the anthropometric data among the non-ART, ART, and NC children at 6 years of age. Conclusion: At 6 years of age, term singletons were taller in the FreET group than in the non-ART group, after adjusting for confounders.

Usefulness of combined NGS and QF-PCR analysis for product of conception karyotyping.

Purpose: Since chromosomal abnormalities can be detected in more than half of miscarriages, cytogenetic testing of the product of conception (POC) can provide important information when preparing for a subsequent pregnancy. Conventional karyotyping is the common diagnostic method for a POC but can be problematic due to the need for cell culture. Methods: We here conducted shallow whole-genome sequencing (sWGS) using next-generation sequencing (NGS) for alternative POC cytogenomic analysis. Since female euploidy samples can include 69,XXX triploidy, additional QF-PCR was performed in these cases. Results: We here analyzed POC samples from miscarriages in 300 assisted reproductive technology (ART) pregnancies and detected chromosomal abnormalities in 201 instances (67.0%). Autosomal aneuploidy (151 cases, 50.3%) was the most frequent abnormality, consistent with prior conventional karyotyping data. Mosaic aneuploidy was detected in seven cases (2.0%). Notably, the frequency of triploidy was 2.3%, 10-fold lower than the reported frequency in non-ART pregnancies. Structural rearrangements were identified in nine samples (3%), but there was no case of segmental mosaicism. Conclusions: These data suggest that NGS-based sWGS, with the aid of QF-PCR, is a viable alternative karyotyping procedure that does not require cell culture. This method could also assist with genetic counseling for couples who undergoes embryo selection based on PGT-A data.

Creation, effects on embryo quality, and clinical outcomes of a new embryo culture medium with 31 optimized components derived from human oviduct fluid: A prospective multicenter randomized trial.

Purpose: Our aim is to make an ideal embryo culture medium close to human oviduct fluid (HOF) components, and to evaluate the quality of this medium with embryo quality and clinical outcomes in assisted reproductive technology (ART) by a prospective randomized controlled trial (RCT). Methods: Study I: HOF was collected laparoscopically from patients (n = 28) with normal pelvic findings. According to HOF analysis results, the new medium "HiGROW OVIT®" (OVIT) was designed. Study II: Embryos (2 pronuclei (2PN) = 9633) were assigned from 1435 patients. The blastulation rate (BR), good BR (gBR), utilized (transferred/cryo-preserved) BR (uBR), pregnancy rate (PR), and miscarriage rate (MR) were compared between the OVIT and control groups by RCT. Results: The novel medium 'OVIT' was produced according to 31 HOF components. The concentrations of essential amino acids (e-AAs) were lower in OVIT than in current media, yet the opposite was true for ne-AA concentrations. gBR and uBR were higher in the OVIT group than in the control group. In the older female group, gBT and uBR were significantly higher in the OVIT group. Conclusions: The novel medium 'OVIT' was produced according to HOF data. The OVIT had significantly better embryo quality and clinical outcomes than the current media.

Preimplantation genetic testing for aneuploidy: a comparison of live birth rates in patients with recurrent pregnancy loss due to embryonic aneuploidy or recurrent implantation failure.

STUDY QUESTION: Can preimplantation genetic testing for aneuploidy (PGT-A) improve the live birth rate and reduce the miscarriage rate in patients with recurrent pregnancy loss (RPL) caused by an abnormal embryonic karyotype and recurrent implantation failure (RIF)? SUMMARY ANSWER: PGT-A could not improve the live births per patient nor reduce the rate of miscarriage, in both groups. WHAT IS KNOWN ALREADY: PGT-A use has steadily increased worldwide. However, only a few limited studies have shown that it improves the live birth rate in selected populations in that the prognosis has been good. Such studies have excluded patients with RPL and RIF. In addition, several studies have failed to demonstrate any benefit at all. PGT-A was reported to be without advantage in patients with unexplained RPL whose embryonic karyotype had not been analysed. The efficacy of PGT-A should be examined by focusing on patients whose previous products of conception (POC) have been aneuploid, because the frequencies of abnormal and normal embryonic karyotypes have been reported as 40-50% and 5-25% in patients with RPL, respectively. STUDY DESIGN, SIZE, DURATION: A multi-centre, prospective pilot study was conducted from January 2017 to June 2018. A total of 171 patients were recruited for the study: an RPL group, including 41 and 38 patients treated respectively with and without PGT-A, and an RIF group, including 42 and 50 patients treated respectively with and without PGT-A. At least 10 women in each age group (35-36, 37-38, 39-40 or 41-42 years) were selected for PGT-A groups. PARTICIPANTS/MATERIALS, SETTING, METHODS: All patients and controls had received IVF-ET for infertility. Patients in the RPL group had had two or more miscarriages, and at least one case of aneuploidy had been ascertained through prior POC testing. No pregnancies had occurred in the RIF group, even after at least three embryo transfers. Trophectoderm biopsy and array comparative genomic hybridisation (aCGH) were used for PGT-A. The live birth rate of PGT-A and non-PGT-A patients was compared after the development of blastocysts from up to two oocyte retrievals and a single blastocyst transfer. The miscarriage rate and the frequency of euploidy, trisomy and monosomy in the blastocysts were noted. MAIN RESULT AND THE ROLE OF CHANCE: There were no significant differences in the live birth rates per patient given or not given PGT-A: 26.8 versus 21.1% in the RPL group and 35.7 versus 26.0% in the RIF group, respectively. There were also no differences in the miscarriage rates per clinical pregnancies given or not given PGT-A: 14.3 versus 20.0% in the RPL group and 11.8 versus 0% in the RIF group, respectively. However, PGT-A improved the live birth rate per embryo transfer procedure in both the RPL (52.4 vs 21.6%, adjusted OR 3.89; 95% CI 1.16-13.1) and RIF groups (62.5 vs 31.7%, adjusted OR 3.75; 95% CI 1.28-10.95). Additionally, PGT-A was shown to reduce biochemical pregnancy loss per biochemical pregnancy: 12.5 and 45.0%, adjusted OR 0.14; 95% CI 0.02-0.85 in the RPL group and 10.5 and 40.9%, adjusted OR 0.17; 95% CI 0.03-0.92 in the RIF group. There was no difference in the distribution of genetic abnormalities between RPL and RIF patients, although double trisomy tended to be more frequent in RPL patients. LIMITATIONS, REASONS FOR CAUTION: The sample size was too small to find any significant advantage for improving the live birth rate and reducing the clinical miscarriage rate per patient. Further study is necessary. WIDER IMPLICATION OF THE FINDINGS: A large portion of pregnancy losses in the RPL group might be due to aneuploidy, since PGT-A reduced the overall incidence of pregnancy loss in these patients. Although PGT-A did not improve the live birth rate per patient, it did have the advantage of reducing the number of embryo transfers required to achieve a similar number live births compared with those not undergoing PGT-A. STUDY FUNDING/COMPETING INTEREST(S): This study was supported by the Japan Society of Obstetrics and Gynecology and grants from the Japanese Ministry of Education, Science, and Technology. There are no conflicts of interest to declare. TRIAL REGISTRATION NUMBER: N/A.

Prediction of the in vitro developmental competence of early-cleavage-stage human embryos with time-lapse imaging and oxygen consumption rate measurement.

PURPOSE: To assess an embryo's ability to develop into a good-quality blastocyst during the early-cleavage stage using time-lapse imaging and the oxygen consumption rate. METHODS: In total, 942 zygotes had their oxygen consumption rates measured. In total, 282 zygotes were assessed by using time-lapse imaging. In total, 121 zygotes were examined by using both their oxygen consumption rate and time-lapse imaging. RESULTS: The embryos with moderate respiration rates of between 0.41 and 0.61 (×1014/mol s-1) on day 3 had a 22.1% chance of becoming good-quality blastocysts; those outside that range had a 14.3% chance. With the time-lapse system, when the first division was within 24 hours, 22.3% of the embryos grew to good blastocysts. After 24 hours, the rate dropped to 8.6%. The intervals between two consecutive cleavages were calculated and the duration of the second cell cycle was defined. When the time was between nine hours and 13 hours, there was a higher rate of good blastocysts. Regarding both criteria, when the embryos had progressed in the optimal range, a high percentage of them had become good blastocysts; it was 8.0% outside of that range. CONCLUSION: Individual embryos with the potential to develop into good-quality blastocysts could be selected at day 3 of culture using these systems.

Effects of cyclophosphamide administration on the in vitro fertilization of mice.

PURPOSE: To evaluate the oocyte fertilization ability and embryo growth after cyclophosphamide (CPA) treatment in mice. METHODS: Mice were treated with CPA at different doses (0-800 mg/kg body weight). The oocytes then were retrieved and evaluated for their in vitro fertilization efficiency. RESULTS: The average number of metaphase II (MII) oocytes significantly decreased by ≥400 mg/kg CPA administration. The fertilization rate also decreased in the group that was treated with ≥400 mg/kg CPA. However, after fertilization, the embryos demonstrated normal growth ability. Two weeks after CPA administration, the number of mice from which the oocytes could be retrieved markedly decreased, but the fertilization rate and development of morphological features in the embryos were similar to those of the controls. One month after CPA administration, the number of mice from which the oocytes could be retrieved, fertilization rate, and development of the morphological features in the embryos were similar to those of the controls. CONCLUSION: The number of oocytes decreased as the CPA administration level increased; however, the oocytes' potential for fertilization and development to the blastocyst stage was not significantly affected. One month after CPA administration, the number of oocytes and the potential for development into blastocysts were recovered.

Genome-wide analysis of DNA methylation dynamics during early human development.

DNA methylation is globally reprogrammed during mammalian preimplantation development, which is critical for normal development. Recent reduced representation bisulfite sequencing (RRBS) studies suggest that the methylome dynamics are essentially conserved between human and mouse early embryos. RRBS is known to cover 5-10% of all genomic CpGs, favoring those contained within CpG-rich regions. To obtain an unbiased and more complete representation of the methylome during early human development, we performed whole genome bisulfite sequencing of human gametes and blastocysts that covered>70% of all genomic CpGs. We found that the maternal genome was demethylated to a much lesser extent in human blastocysts than in mouse blastocysts, which could contribute to an increased number of imprinted differentially methylated regions in the human genome. Global demethylation of the paternal genome was confirmed, but SINE-VNTR-Alu elements and some other tandem repeat-containing regions were found to be specifically protected from this global demethylation. Furthermore, centromeric satellite repeats were hypermethylated in human oocytes but not in mouse oocytes, which might be explained by differential expression of de novo DNA methyltransferases. These data highlight both conserved and species-specific regulation of DNA methylation during early mammalian development. Our work provides further information critical for understanding the epigenetic processes underlying differentiation and pluripotency during early human development.

Risk factors for placenta accreta spectrum in pregnancies conceived after frozen-thawed embryo transfer in a hormone replacement cycle.

OBJECTIVE: Assisted reproductive technology (ART), especially frozen-thawed embryo transfer (FET) in a hormone replacement cycle (HRC), is a risk factor for placenta accreta spectrum (PAS). This study aimed to clarify the risk factors for PAS related to the maternal background and ART techniques in pregnancies achieved after FET in an HRC. STUDY DESIGN: We performed a case-control study in two tertiary perinatal centres in Japan. Among 14,028 patients who delivered at ≥24 weeks of gestation or were transferred after delivery to two tertiary perinatal centres between 2010 and 2021, 972 conceived with ART and 13,056 conceived without ART. PAS was diagnosed on the basis of the FIGO classification for the clinical diagnosis of PAS or retained products of conception after delivery at ≥24 weeks of gestation. We excluded women with fresh embryo transfer, FET with a spontaneous ovulatory cycle, a donor oocyte cycle, and missing details of the ART treatment. Finally, among women who conceived after FET in an HRC, 62 with PAS and 340 without PAS were included in this study. Multivariate logistic regression models were used for case-control comparisons, with adjustment for maternal age at delivery, parity, endometriosis or adenomyosis, the number of previous uterine surgeries of caesarean section, myomectomy, endometrial polypectomy or endometrial curettage, placenta previa, the stage of transferred embryos, and endometrial thickness at the initiation of progestin administration. RESULTS: PAS was associated with ≥2 previous uterine surgeries (adjusted odds ratio, 3.57; 95 % confidence interval, 1.60-7.97) and the stage of embryo transfer (blastocysts: adjusted odds ratio, 2.89; 95 % confidence interval, 1.15-7.26). In patients with <2 previous uterine surgeries, PAS was associated with an endometrial thickness of <7.0 mm (adjusted odds ratio, 5.18; 95 % confidence interval, 1.10-24.44). CONCLUSION: Multiple uterine surgeries and the transfer of blastocysts are risk factors for PAS in pregnancies conceived after FET in an HRC. In women with <2 previous uterine surgeries, a thin endometrium before FET is also a risk factor for PAS in these pregnancies.

A questionnaire-based survey to assess patient satisfaction, ease-of-learning, ease-of-use, injection site pain and overall patient satisfaction of the follitropin-alpha (Gonal-f) filled-by-mass (FbM) prefilled pen compared with other systems of gonadotrophin administration.

BACKGROUND: Gonadotrophins are used routinely for follicular stimulation during ovarian induction and assisted reproduction techniques. Developments in recombinant follicle-stimulating hormone preparations and their injection devices have improved patient quality of life by enabling patients to self-administer treatment at home. The objective of this study was to investigate patient experiences of learning to use and overall satisfaction with the follitropin-alpha (Gonal-f) filled-by-mass (FbM) prefilled pen. METHODS: This questionnaire-based survey study was conducted in 23 fertility centres in Japan over a period of 14 months. Patients who were receiving fertility treatment with the follitropin-alpha (FbM) prefilled pen were asked to complete a questionnaire to assess their satisfaction, ease of learning and use, and injection site pain following treatment. RESULTS: A total of 663 women participated in the study. The majority of patients found the instructions for administering follitropin-alpha with the prefilled pen easy to understand (83.0%; n = 546/658) and patients found that a hands-on demonstration by a nurse or doctor was the most useful tool for learning to use the follitropin-alpha (FbM) prefilled pen (80.0%; n = 497/621). Forty-eight percent (n = 318) of patients in the study had previous experience with different types of fertility medications and the majority of these patients found the follitropin-alpha (FbM) prefilled pen easier to use (75.1%; n = 232/309) and less painful (89.0%; n = 347/390) than their previous medication. The majority (80.2%; n = 521/650) of patients reported overall satisfaction with the follitropin-alpha (FbM) prefilled pen. CONCLUSIONS: The follitropin-alpha (FbM) prefilled pen is an easy-to-use injection device according to this questionnaire-based survey. Patients who had experience of different types of fertility medication preferred the follitropin-alpha (FbM) prefilled pen to other injection devices.

The Possibility of Analyzing Endometrial Receptivity Using Cells from Embryo Transfer Catheters.

It is very important to investigate the expression of endometrial receptive markers in the endometrium during implantation. Therefore, we examined whether it would be possible to analyze endometrial receptivity using cells from embryo transfer catheters. A total of 81 cycles from 81 consenting patients were enrolled in this study. The tip of the embryo transfer (ET) catheter was cut and immersed in a dedicated reagent. Confirmation of cell distribution was carried out using a Papanicolaou stain and immunocytochemistry. Protein expression was carried out by immunocytochemistry. The expressions of estrogen receptor α, progesterone receptor, and homeobox A10 mRNA were analyzed using quantitative reverse transcription-polymerase chain reaction. We analyzed the relationship between the gene expression profiles associated with pregnancy from endometrial cells. Samples collected from the ET catheter showed clear staining for endometrial cells. Most of the cells were endometrial epithelial cells. Cervical cells were not observed. The protein expression was also confirmed. Three genes were analyzed that are associated with endometrial receptivity. Progesterone receptor expression was 1.4-fold (p<0.05) and homeobox A10 was 2.8-fold (p<0.01) higher in patients who became non-pregnant group, compared to the pregnant group. Estrogen receptor α expression tended to be higher in the non-pregnant group (p=0.18). Our results suggest that endometrial receptivity can be evaluated using cells obtained from the ET catheter. This method may be useful for elucidating the cause of implantation failure by comparing a receptive and non-receptive endometrium at the time of ET.

Chromosome analysis of human refrozen embryos following fluorescence in situ hybridization.

PURPOSE: Several recent reports have discussed refrozen and thawed embryo transfer; however, the process may cause a degree of chromosomal damage and subtle genomic mutation. In view of this possibility, the purpose of this study was to investigate the incidence of aneuploidy in refrozen embryos. METHODS: In order to investigate the incidence of aneuploidy and mosaicism observed in chromosome 1, fluorescent in situ hybridization (FISH) was used on surviving embryos that first underwent one freeze-thaw cycle, then were allowed to develop to the blastocyst stage, and subsequently survived a second freeze-thaw cycle. RESULTS: Of 1,132 blastomeric nuclei analyzed from 15 refrozen embryos, disomy was found in 82.9%. In contrast, for the 11 blastocysts subjected to only one freeze-thaw cycle, disomy was noted in 78.4%. Of the 197 blastomeric nuclei analyzed in all arrested embryos, disomy was found in 51.8%. CONCLUSIONS: The refreezing process did not increase aneuploidy. The good and fair morphology groups demonstrated a higher percentage of disomy than the poor morphology group regardless of whether they were frozen once or twice.

Decidualization modulates a signal transduction system via protease-activated receptor-1 in endometrial stromal cells.

PROBLEM: Decidual cells are thought to be involved in the maintenance of pregnancy. We conducted this study to evaluate the cellular function of endometrial stromal cells (ESCs) transitioning to decidualization. METHODS OF STUDY: Normal endometrial specimens were obtained from premenopausal patients who had undergone hysterectomies for subserosal leiomyomas. Decidualization of the ESCs (DSCs) was induced by incubating subconfluent cells in media containing medroxyprogesterone acetate and dibutyryl-cyclic adenosine monophosphate. We first analyzed the expression profile of protease-activated receptor-1 (PAR-1) between ESCs and DSCs. To investigate the intracellular signal transduction system in the DSCs, we incubated cells with thrombin receptor activator peptide 6 (TRAP-6). The levels of IL-8, monocyte chemo-attractant protein-1, matrix metalloproteinase (MMP)-1, and vascular endothelial growth factor in the culture medium were measured by enzyme-linked immunosorbent assays. The activation of the MAP kinase signaling pathway was detected by a Western blot analysis. The activation was evaluated for the expression of p21. RESULTS: PAR-1 receptor expression is upregulated in DSCs. The productions of chemokine and MMP-1 increased in the DSCs with the addition of TRAP-6. The activity of both the ERK-1 and ERK-2 isoforms was increased by 5-15 minute after TRAP-6 treatment. p70 S6 kinase showed the strongest expression after 1 hour. p21 was strongly observed in ESCs compared to the DSCs. CONCLUSION: Our results suggest that cell function is changed by decidualization in association with increasing PAR-1 expression. The upregulation of PAR-1 may have some influence on pregnancy in the decidua.

Factors associated with aberrant imprint methylation and oligozoospermia.

Disturbingly, the number of patients with oligozoospermia (low sperm count) has been gradually increasing in industrialized countries. Epigenetic alterations are believed to be involved in this condition. Recent studies have clarified that intrinsic and extrinsic factors can induce epigenetic transgenerational phenotypes through apparent reprogramming of the male germ line. Here we examined DNA methylation levels of 22 human imprinted loci in a total of 221 purified sperm samples from infertile couples and found methylation alterations in 24.8% of the patients. Structural equation model suggested that the cause of imprint methylation errors in sperm might have been environmental factors. More specifically, aberrant methylation and a particular lifestyle (current smoking, excess consumption of carbonated drinks) were associated with severe oligozoospermia, while aging probably affected this pathology indirectly through the accumulation of PCB in the patients. Next we examined the pregnancy outcomes for patients when the sperm had abnormal imprint methylation. The live-birth rate decreased and the miscarriage rate increased with the methylation errors. Our research will be useful for the prevention of methylation errors in sperm from infertile men, and sperm with normal imprint methylation might increase the safety of assisted reproduction technology (ART) by reducing methylation-induced diseases of children conceived via ART.

Granulocyte colony-stimulating factor as a potential inducer of ovulation in infertile women with luteinized unruptured follicle syndrome.

Luteinized unruptured follicle (LUF) syndrome is one of the intractable ovulation disorders that are commonly observed during cycles of treatment with ovulation inducers, for which no effective therapy other than assisted reproductive technology is available. Here, we investigated whether granulocyte colony-stimulating factor (G-CSF) could prevent the onset of LUF syndrome. We analyzed the effects of G-CSF in 68 infertile women with LUF syndrome who received ovulation induction (clomiphene + human chorionic gonadotropin [hCG] therapy or follicle-stimulating hormone + hCG therapy). G-CSF (lenograstim, 100 µg) was administered subcutaneously. Onsets of LUF syndrome were compared between the cycle during which G-CSF was given in combination with the ovulation inducer (ie, the G-CSF treatment cycle) and the subsequent cycle during which only the ovulation inducer was given (ie, the G-CSF nontreatment control cycle). The results showed that LUF syndrome recurred in only 3 cycles during the G-CSF treatment cycle (4.4% [3/68 cycles]), whereas LUF syndrome recurred in 13 cycles during the subsequent G-CSF nontreatment control cycle (19.1% [13/68 cycles]). The additional use of G-CSF significantly prevented the onset of LUF syndrome during ovulation induction (P = 0.013, McNemar test). No serious adverse reactions because of the administration of G-CSF were observed. In conclusion, our findings indicate that G-CSF may become a useful therapy for LUF syndrome.

Peritonitis after a ruptured left pyosalpinx in a patient undergoing in vitro fertilization.

OBJECTIVE: To report acute abdomen in a young woman with infertility due to small asymptomatic bilateral hydrosalpinges who was on the 12th day of an IVF cycle. DESIGN: Case report. SETTING: Private IVF clinic. PATIENT(S): A 35-year-old woman with asymptomatic bilateral hydrosalpinges. INTERVENTION(S): Abdominal laparoscopy. MAIN OUTCOME MEASURE(S): Pus and a ruptured left pyosalpinx. RESULTS: The patient suddenly developed acute abdomen while lifting a disabled person at a nursing home where she worked as a nurse. About 200 mL of pus was aspirated, and the patient had a ruptured left pyosalpinx. Bilateral salpingectomy was done by laparoscopy; the patient's postoperative recovery was uneventful. CONCLUSION: We report a rare case of acute abdomen due to peritonitis after a ruptured pyosalpinx in an IVF patient who lifted a disabled person.

Developmental potential and chromosomal constitution of embryos derived from larger single pronuclei of human zygotes used in in vitro fertilization.

Blastocysts that develop from larger 1 pronuclear zygotes are suspected to be diploid and are comparable in development potential to 2 pronuclear zygotes.

Assessing loss of imprint methylation in sperm from subfertile men using novel methylation polymerase chain reaction Luminex analysis.

OBJECTIVE: To assess the clinical value of bisulfite polymerase chain reaction Luminex (BPL), an automated, high-throughput procedure for the detection of alterations in DNA methylation. DESIGN: Experimental prospective study. SETTING: University research laboratory and private in vitro fertilization (IVF) clinic. PATIENT(S): A total of 337 men, 61 with severe oligozoospermia, 67 with moderate oligozoospermia, and 209 with microscopically normozoospermia. INTERVENTION(S): The ejaculated sperm samples after the routine semen analysis with patients' consent. MAIN OUTCOME MEASURE(S): Examination of the methylation patterns of eight imprinted loci in sperm DNA, and confirmation with combined bisulfite PCR restriction analysis (COBRA). RESULT(S): A total of 47 cases (13.9%) showed abnormal methylation at one or more imprinted loci (18 paternal, 18 maternal, and 11 cases with alterations of both maternal and paternal imprints). CONCLUSION(S): The relative ease of the BPL method provides a practical method within a clinical setting to reduce the likelihood of abnormal samples being used in assisted reproduction treatments.

The efficacy of the transfer of twice frozen-thawed embryos with the vitrification method.

OBJECTIVE: To confirm the clinical benefits of recryopreserved, twice-thawed embryo transfer (ET). DESIGN: Retrospective study. SETTING: Private fertility clinic. PATIENT(S): Forty-nine women whose embryos had been refrozen after a previous frozen-thawed ET. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Comparison of implantation and pregnancy rates of twice-cryopreserved, twice-thawed embryos versus once-cryopreserved, once-thawed embryos. RESULT(S): The pregnancy rate per ET cycle was 27.8% in the refrozen group and 25.9% in the control group (no statistically significant difference). The implantation rate was 25.0% in the refrozen group and 19.3% in the control group (no statistically significant difference). CONCLUSION(S): The refreezing of supernumerary embryos can prevent ovarian hyperstimulation syndrome in stimulated patients and in those who have experienced repeated failed pregnancies. If unexpected supernumerary embryos are available for recryopreservation after frozen-thawed ET, these embryos may be revitrified for a future transfer.

DNA methylation errors at imprinted loci after assisted conception originate in the parental sperm.

There is an increased prevalence of imprinting disorders, such as Beckwith-Wiedemann syndrome, associated with human assisted reproductive technologies (ART). Work on animal models suggests that in vitro culture may be the source of these imprinting errors. However, in this study we report that, in some cases, the errors are inherited from the father. We analyzed DNA methylation at seven autosomal imprinted loci and the XIST locus in 78 paired DNA samples. In seven out of seventeen cases where there was abnormal DNA methylation in the ART sample (41%), the identical alterations were present in the parental sperm. Furthermore, we also identified DNA sequence variations in the gene encoding DNMT3L, which were associated with the abnormal paternal DNA methylation. Both the imprinting errors and the DNA sequence variants were more prevalent in patients with oligospermia. Our data suggest that the increase in the incidence of imprinting disorders in individuals born by ART may be due, in some cases, to the use of sperm with intrinsic imprinting mutations.