A heatmap for expected cumulative live birth rate in preimplantation genetic testing for monogenic disorders and chromosomal structural rearrangements.

PURPOSE: Our objective is to predict the cumulative live birth rate (CLBR) and identify the specific subset within the population undergoing preimplantation genetic testing for monogenic disorders (PGT-M) and chromosomal structural rearrangements (PGT-SR) which is likely to exhibit a diminished expected CLBR based on various patient demographics. METHODS: We performed a single-centre retrospective cohort study including 1522 women undergoing 3130 PGT cycles at a referral centre for PGT. A logistic regression analysis was performed to predict the CLBR per ovarian stimulation in women undergoing PGT-M by polymerase chain reaction (PCR) or single-nucleotide polymorphism (SNP) array, and in women undergoing PGT-SR by SNP array, array comparative genomic hybridization (CGH) or next-generation sequencing (NGS). RESULTS: The mean age of women was 32.6 years, with a mean AMH of 2.75 µg/L. Female age and AMH significantly affected the expected CLBR irrespective of the inheritance mode or PGT technology. An expected CLBR < 10% was reached above the age of 42 years and AMH ≤ 1.25 µg/L. We found no significant difference in outcome per ovarian stimulation between the different PGT technologies, i.e. PCR, SNP array, array CGH and NGS. Whereas per embryo transfer, we noticed a significantly higher probability of live birth when SNP array, array CGH and NGS were used as compared to PCR. CONCLUSION: In a PGT-setting, couples with an unfavourable female age and AMH should be informed of the prognosis to allow other reproductive choices. The heatmap produced in this study can be used as a visual tool for PGT couples.

Cleavage-stage or blastocyst-stage embryo biopsy has no impact on growth and health in children up to 2 years of age.

BACKGROUND: Studies show conflicting results on neonatal outcomes following embryo biopsy for PGT, primarily due to small sample sizes and/or heterogeneity in the timing of embryo biopsy (day 3; EBD3 or day 5/6; EBD5) and type of embryo transfer. Even fewer data exist on the impact on children's health beyond the neonatal period. This study aimed to explore outcomes in children born after EBD3 or EBD5 followed by fresh (FRESH) or frozen-thawed embryo transfer (FET). METHODS: This single-centre cohort study compared birth data of 630 children after EBD3, of 222 EBD5 and of 1532 after non-biopsied embryo transfers performed between 2014 and 2018. Follow-up data on growth were available for 426, 131 and 662 children, respectively. RESULTS: Embryo biopsy, either at EBD3 or EBD5 in FET and FRESH cycles did not negatively affect anthropometry at birth, infancy or childhood compared to outcomes in non-biopsied FET and FRESH cycles. While there was no adverse effect of the timing of embryo biopsy (EBD3 versus EBD5), children born after EBD3 followed by FET had larger sizes at birth, but not thereafter, than children born after EBD3 followed by FRESH. Reassuringly, weight and height gain, proportions of major congenital malformations, developmental problems, hospital admissions and surgical interventions were similar between comparison groups. CONCLUSION: Our study indicated that neither EBD3 nor EBD5 followed by FRESH or FET had a negative impact on anthropometry and on health outcomes up to 2 years of age.

Electronic witnessing in the medically assisted reproduction laboratory: insights and considerations after 10 years of use.

STUDY QUESTION: What have we learnt after 10 years of electronic witnessing? SUMMARY ANSWER: When applied correctly, an electronic witnessing system can replace manual witnessing in the medically assisted reproduction lab to prevent sample mix-up. WHAT IS KNOWN ALREADY: Electronic witnessing systems have been implemented to improve the correct identification, processing, and traceability of biological materials. When non-matching samples are simultaneously present in a single workstation, a mismatch event is generated to prevent sample mix-up. STUDY DESIGN, SIZE, DURATION: This evaluation investigates the mismatch and administrator assign rate over a 10-year period (March 2011-December 2021) with the use of an electronic witnessing system. Radiofrequency identification tags and barcodes were used for patient and sample identification. Since 2011, IVF and ICSI cycles and frozen embryo transfer cycles (FET) were included; IUIs cycles were included since 2013. PARTICIPANTS/MATERIALS, SETTING, METHODS: The total number of tags and witnessing points were recorded. Witnessing points in a particular electronic witnessing system represent all the actions that have been performed from gamete collection through embryo production, to cryopreservation and transfer. Mismatches and administrator assigns were collected and stratified per procedure (sperm preparation, oocyte retrieval, IVF/ICSI, cleavage stage embryo or blastocyst embryo biopsy, vitrification and warming, embryo transfer, medium changeover, and IUI). Critical mismatches (such as mislabelling or non-matching samples within one work area) and critical administrator assigns (such as samples not identified by the electronic witnessing system and unconfirmed witnessing points) were selected. MAIN RESULTS AND THE ROLE OF CHANCE: A total of 109 655 cycles were included: 53 023 IVF/ICSI, 36 347 FET, and 20 285 IUI cycles. The 724 096 used tags, led to a total of 849 650 witnessing points. The overall mismatch rate was 0.251% (2132/849 650) per witnessing point and 1.944% per cycle. In total, 144 critical mismatches occurred over the different procedures. The yearly mean critical mismatch rate was 0.017 ± 0.007% per witnessing point and 0.129 ± 0.052% per cycle. The overall administrator assign rate was 0.111% (940/849 650) per witnessing point and 0.857% per cycle, including 320 critical administrator assigns. The yearly mean critical administrator assign rate was 0.039 ± 0.010% per witnessing point and 0.301 ± 0.069% per cycle. Overall mismatch and administrator assign rates remained fairly stable during the evaluated time period. Sperm preparation and IVF/ICSI were the procedures most prone to critical mismatch and administrator assigns. LIMITATIONS, REASONS FOR CAUTION: The procedures and methods of integration of an electronic witnessing system may vary from one laboratory to another and result in differences in the potential risks related to sample identification. Individual embryos cannot (yet) be identified by such a system; this makes extra manual witnessing indispensable at certain critical steps where potential errors are not recorded. The electronic witnessing system still needs to be used in combination with manual labelling of both the bottom and lid of dishes and tubes to guarantee correct assignment in case of malfunction or incorrect use of radiofrequency identification tags. WIDER IMPLICATIONS OF THE FINDINGS: Electronic witnessing is considered to be the ultimate tool to safeguard correct identification of gametes and embryos. But this is only possible when used correctly, and proper training and attention of the staff is required. It may also induce new risks, i.e. blind witnessing of samples by the operator. STUDY FUNDING/COMPETING INTEREST(S): No funding was either sought or obtained for this study. J.S. presents webinars on RIW for CooperSurgical. The remaining authors have nothing to declare. TRIAL REGISTRATION NUMBER: N/A.

Multiple vitrification-warming and biopsy procedures on human embryos: clinical outcome and neonatal follow-up of children.

STUDY QUESTION: Does double vitrification and warming of human blastocysts having undergone biopsy once or twice have an impact on the clinical outcome? SUMMARY ANSWER: The clinical pregnancy rate obtained with double vitrification single biopsy blastocysts was comparable to that obtained with single vitrification single biopsy blastocysts in our center in the same time period (46%; 2016-2018), whereas that obtained with double-vitrified double-biopsied blastocysts seemed lower and will need further study. WHAT IS KNOWN ALREADY: Genetic testing on cryopreserved unbiopsied embryos involves two cryopreservation procedures. Retesting of failed/inconclusive-diagnosed blastocysts inevitably involves a second round of biopsy and a second round of vitrification as well. To what extent this practice impacts on the developmental potential of blastocysts has been studied to a limited extent so far and holds controversy. Additionally, the obstetrical/perinatal outcome after the transfer of double-vitrified/single or double-biopsied blastocysts is poorly documented. STUDY DESIGN, SIZE, DURATION: This retrospective observational study included 97 cycles of trophectoderm biopsy and preimplantation genetic testing (PGT) on vitrified-warmed embryos followed by a second round of vitrification between March 2015 and December 2019. PARTICIPANTS/MATERIALS, SETTING, METHODS: In 36 warming cycles, no biopsy was performed on the embryos before the first vitrification (single biopsy group). In 61 warming cycles, the embryos had been biopsied on Day 3 (n = 4) or on Day 5/6 (n = 57) before the first vitrification (double biopsy group). A second biopsy was mostly indicated in cycles of failed or inconclusive diagnosis at the first biopsy. Two cycles involved a more specific mutation test for X-linked diseases on male embryos and one cycle involved testing for a second monogenic indication supplementary to a previously tested reciprocal translocation. Post-warming suitability for biopsy, availability of genetically transferable embryos and clinical outcome of subsequent frozen-thawed embryo transfer (FET) cycles were reported. Neonatal follow-up of the children was included. MAIN RESULTS AND THE ROLE OF CHANCE: In total, 91 cleavage-stage embryos and 154 blastocysts were warmed, of which 34 (37.4%) and 126 (81.8%), respectively, were of sufficient quality to undergo trophectoderm biopsy and were subsequently vitrified for a second time. Out of these, 92 underwent biopsy for the first time (single biopsy), whereas 68 underwent a second biopsy (double biopsy). After diagnosis, 77 blastocysts (48.1%) were revealed to be genetically transferable (44 in the single biopsy group and 33 in the double biopsy group). In 46 warming cycles, 51 blastocysts were warmed and 49 survived this second warming procedure (96.0%). Subsequently, there were 45 FET cycles resulting in 27 biochemical pregnancies and 18 clinical pregnancies with fetal heartbeat (40.0% per FET cycle: 44.0% in the single biopsy group and 35.0% in the double biopsy group, P = 0.54). Thirteen singletons were born (eight in the single biopsy group and five in the double biopsy group), while three pregnancies were ongoing. A total of 26 embryos (13 in each group) remain vitrified and have the potential to increase the final clinical pregnancy rate. The neonatal follow-up of the children born so far is reassuring. LIMITATIONS, REASONS FOR CAUTION: This is a small retrospective cohort, thus, the implantation potential of double vitrification double biopsy blastocysts, as compared to double vitrification single biopsy blastocysts and standard PGT (single vitrification, single biopsy), certainly needs further investigation. Although one could speculate on birthweight being affected by the number of biopsies performed, the numbers in this study are too small to compare birthweight standard deviation scores in singletons born after single or double biopsy. WIDER IMPLICATIONS OF THE FINDINGS: PGT on vitrified-warmed embryos, including a second vitrification-warming step, results in healthy live birth deliveries, for both single- and double-biopsied embryos. The neonatal follow-up of the 13 children born so far did not indicate any adverse effect. The present study is important in order to provide proper counseling to couples on their chance of a live birth per initial warming cycle planned and concerning the safety issue of rebiopsy and double vitrification. STUDY FUNDING/COMPETING INTEREST(S): None. TRIAL REGISTRATION NUMBER: N/A.

PREIMPLANTATION GENETIC TESTING: Clinical experience of preimplantation genetic testing.

Thirty years of rapid technological advances in the field of genetic testing and assisted reproduction have reshaped the procedure of preimplantation genetic testing (PGT). The development of whole genome amplification and genome-wide testing tools together with the implementation of optimal hormonal stimulation protocols and more efficient cryopreservation methods have led to more accurate diagnoses and improved clinical outcomes. In addition, the shift towards embryo biopsy at day 5/6 has changed the timeline of a typical PGT clinical procedure. In this paper, we present an up-to-date overview of the different steps in PGT from patient referral to baby follow-up.

Birthweight of singletons born after blastocyst-stage or cleavage-stage transfer: analysis of a data set from three randomized controlled trials.

PURPOSE: The present post hoc analysis aims to study the neonatal data of singletons born from three randomized controlled trials (RCTs) which compared the outcome of day 3 and day 5 transfers. METHODS: Our analysis included 208 liveborn singletons from three existing RCTs (publication dates 2004, 2005, and 2006), 93 children from cleavage-stage transfers and 115 from blastocyst-stage transfers. Vanishing twins were excluded from the analysis. Singleton birthweight was the primary outcome measure. Gestational age and gender of the newborn were accounted for in the multiple regression analysis, along with other confounding factors, such as maternal age, BMI, parity, and smoking behavior. RESULTS: There was no significant difference in gestational age (median, interquartile range) between cleavage-stage transfer (275 days; 267-281) and blastocyst-stage transfer (277 days; 270-281; p = 0.22). Singleton birthweight (median, interquartile range) was not significantly different between cleavage-stage transfer (3330 g; 3020-3610) and blastocyst-stage transfer (3236 g; 2930-3630; p = 0.40), even following multivariable regression analysis to control for potential maternal and newborn confounders. CONCLUSION: The gestational age and birthweight were not significantly different after cleavage-stage and blastocyst-stage transfers. One limitation to be recognized is the age of the data, with original data collection dates from 2001 to 2004. Additionally, the RCTs used for the present analysis have a fairly young age restriction.

Birthweight of singletons born after cleavage-stage or blastocyst transfer in fresh and warming cycles.

STUDY QUESTION: Does extended culture to the blastocyst stage affect singleton birthweight after either fresh or vitrified-warmed embryo transfer? SUMMARY ANSWER: Singleton birthweight z-scores did not vary significantly after a fresh blastocyst transfer, whereas the additional effect of vitrification remains inconclusive. WHAT IS KNOWN ALREADY: Observational studies have associated extended culture with an increased risk of preterm birth and low birthweight. On the contrary, in terms of birthweight and gestational age, singletons born after vitrification have been associated with a better perinatal outcome when compared to those born following a fresh transfer. STUDY DESIGN, SIZE, DURATION: Our post-hoc cohort analysis on neonatal outcomes included 447 liveborn singletons was derived from a recent retrospective analysis on cumulative live birth rates after cleavage-stage and blastocyst transfers. These babies were born following a fresh single cleavage-stage transfer (FCT Day 3, n = 113), fresh single blastocyst transfer (FBT Day 5, n = 218), vitrified-warmed cleavage-stage transfer (VCT Day 3, n = 58) or vitrified-warmed blastocyst transfer (VBT Day 5, n = 58). PARTICIPANTS/MATERIALS, SETTING, METHODS: Singleton birthweight was the primary outcome measure. Gestational age and gender of the newborn were accounted for by using birthweight z-scores in a multivariable linear regression analysis, adjusting for other confounders (maternal age, BMI, parity and smoking behaviour). Vanishing twins were excluded from the analysis. MAIN RESULTS AND THE ROLE OF CHANCE: A significantly lower z-score was observed after blastocyst transfer compared to cleavage-stage transfer in the vitrified-warmed Day 5 group (P = 0.013), a difference not observed in the fresh transfer groups (P = 0.32). Following multivariable regression analysis [adjusted regression coefficient (95% confidence interval)], the FCT and FBT groups showed no significant influence on the birthweight z-scores after fresh transfer [-0.19 (-0.44; 0.05)], but the transfer of vitrified blastocysts (VBT) was associated with a lower birthweight [-0.52 (-0.90; -0.15)] compared with the transfer of vitrified cleavage-stage embryos (VCT). LIMITATIONS, REASONS FOR CAUTION: The present cohort was relatively small, especially in the vitrified-warmed subgroups. Pregnancy-associated factors possibly influencing birthweight (such as diabetes, hypertension, pre-eclampsia) were also not accounted for in the analysis. WIDER IMPLICATIONS OF THE FINDINGS: Different ART procedures, including extended culture and vitrification, may hold potential safety issues. These results require further confirmation in future larger studies. STUDY FUNDING/COMPETING INTEREST(S): None. TRIAL REGISTRATION NUMBER: N/A.

Gonadotropin Releasing Hormone Agonists or Antagonists for Preimplantation Genetic Diagnosis (PGD)? A Prospective Randomised Trial.

BACKGROUND: The use of GnRH analogue medication is essential in reproductive medicine to avoid premature ovulation by pituitary suppression for the duration of ovarian stimulation by gonadotrophins. The type of pituitary suppression by either GnRH agonist analogues versus GnRH antagonist analogues may result in different embryological hence clinical results. Preimplantation genetic diagnosis is a subtype of IVF in which embryos are created for genetic diagnosis of hereditary disorders in order to avoid genetically affected children. Embryological quality hence ovarian stimulation in preimplantation genetic diagnosis is crucial as genetic selection will reduce the number of available embryos to a fraction of the total. OBJECTIVE: The aim of this study was to assess the efficiency of GnRH antagonist versus GnRH agonist treatment for pituitary suppression in ovarian stimulation for PGD, by proxy of number and quality of embryos at cleavage stage available for biopsy. METHOD: We conducted a prospective randomised controlled trial comparing pituitary suppression by GnRH antagonist versus GnRH agonist in ovarian stimulation for PGD. The primary outcome measure was the number of embryos of sufficient quality for biopsy at cleavage stage. Secondary outcome parameters were the number of blastocysts available of top quality, and clinical pregnancy rate. RESULTS: There was no difference in number of oocytes retrieved, embryos at cleavage stage available for biopsy or embryo quality. The clinical pregnancy rate was higher in the GnRH agonist group; however the sample size was insufficient to allow conclusions. CONCLUSION: The use of GnRH agonist versus antagonist treatment does not result in differences in a number of oocytes, embryos or embryo quality in ovarian stimulation for preimplantation genetic diagnosis.

Cumulative live birth rates after fresh and vitrified cleavage-stage versus blastocyst-stage embryo transfer in the first treatment cycle.

STUDY QUESTION: Do cumulative live birth rates differ between single cleavage-stage Day 3 transfer and single blastocyst-stage Day 5 transfer? SUMMARY ANSWER: Cumulative live birth rates after Day 3 and 5 transfers were similar in young patients when the vitrified embryo transfers were also taken into account. WHAT IS KNOWN ALREADY: Previous evidence has shown that the probability of live birth following IVF with a fresh embryo transfer is significantly higher after blastocyst-stage Day 5 transfer. However, because the introduction of vitrification has enhanced the survival of cryopreserved embryos and improved pregnancy rates, the optimal outcome measure for this comparison should now be cumulative live birth rates, as these include the eventual contribution of vitrified-warmed embryos. STUDY DESIGN, SIZE, DURATION: Our retrospective study included first IVF/ICSI cycles performed between January 2010 and December 2013 at a tertiary care centre. PARTICIPANTS/MATERIALS, SETTING, METHODS: All patients were scheduled for fresh single embryo transfer, either on Day 3 (n = 377) or on Day 5 (n = 623). Both IVF and ICSI cycles were included and the sperm used were either fresh or frozen partner ejaculates, or frozen donor ejaculates. The primary outcome was cumulative live birth (after 24 weeks) rate per started cycle, including the eventual contribution of vitrification until the birth of a first child. MAIN RESULTS AND THE ROLE OF CHANCE: Live birth rates per started cycle were significantly lower after transferring the fresh single cleavage-stage embryo, compared to a blastocyst (31.3% and 37.8%, respectively, P = 0.041). Furthermore, the number of embryo transfers necessary until the first live birth was significantly lower for blastocyst-stage embryos (P < 0.001). However, the cumulative live birth rates were 52.6% for cleavage-stage and 52.5% for blastocyst-stage transfers (P = 0.989). LIMITATIONS, REASONS FOR CAUTION: The extrapolation of the results is limited by the retrospective nature of the study. Furthermore, the analysis was restricted to patients under 36 years of age undergoing their first treatment cycle. WIDER IMPLICATIONS OF THE FINDINGS: These results deserve further clinical consideration in terms of time and cost efficiency. A subsequent analysis of the neonatal outcomes is necessary to confirm the safety of treatment cycles using extended culture. STUDY FUNDING/COMPETING INTERESTS: No external funding was received and there are no conflicts of interest to declare.

The why, the how and the when of PGS 2.0: current practices and expert opinions of fertility specialists, molecular biologists, and embryologists.

STUDY QUESTION: We wanted to probe the opinions and current practices on preimplantation genetic screening (PGS), and more specifically on PGS in its newest form: PGS 2.0? STUDY FINDING: Consensus is lacking on which patient groups, if any at all, can benefit from PGS 2.0 and, a fortiori, whether all IVF patients should be offered PGS. WHAT IS KNOWN ALREADY: It is clear from all experts that PGS 2.0 can be defined as biopsy at the blastocyst stage followed by comprehensive chromosome screening and possibly combined with vitrification. Most agree that mosaicism is less of an issue at the blastocyst stage than at the cleavage stage but whether mosaicism is no issue at all at the blastocyst stage is currently called into question. STUDY DESIGN, SAMPLES/MATERIALS, METHODS: A questionnaire was developed on the three major aspects of PGS 2.0: the Why, with general questions such as PGS 2.0 indications; the How, specifically on genetic analysis methods; the When, on the ideal method and timing of embryo biopsy. Thirty-five colleagues have been selected to address these questions on the basis of their experience with PGS, and demonstrated by peer-reviewed publications, presentations at meetings and participation in the discussion. The first group of experts who were asked about 'The Why' comprised fertility experts, the second group of molecular biologists were asked about 'The How' and the third group of embryologists were asked about 'The When'. Furthermore, the geographical distribution of the experts has been taken into account. Thirty have filled in the questionnaire as well as actively participated in the redaction of the current paper. MAIN RESULTS AND THE ROLE OF CHANCE: The 30 participants were from Europe (Belgium, Germany, Greece, Italy, Netherlands, Spain, UK) and the USA. Array comparative genome hybridization is the most widely used method amongst the participants, but it is slowly being replaced by massive parallel sequencing. Most participants offering PGS 2.0 to their patients prefer blastocyst biopsy. The high efficiency of vitrification of blastocysts has added a layer of complexity to the discussion, and it is not clear whether PGS in combination with vitrification, PGS alone, or vitrification alone, followed by serial thawing and eSET will be the favoured approach. The opinions range from in favour of the introduction of PGS 2.0 for all IVF patients, over the proposal to use PGS as a tool to rank embryos according to their implantation potential, to scepticism towards PGS pending a positive outcome of robust, reliable and large-scale RCTs in distinct patient groups. LIMITATIONS, REASONS FOR CAUTION: Care was taken to obtain a wide spectrum of views from carefully chosen experts. However, not all invited experts agreed to participate, which explains a lack of geographical coverage in some areas, for example China. This paper is a collation of current practices and opinions, and it was outside the scope of this study to bring a scientific, once-and-for-all solution to the ongoing debate. WIDER IMPLICATIONS OF THE FINDINGS: This paper is unique in that it brings together opinions on PGS 2.0 from all different perspectives and gives an overview of currently applied technologies as well as potential future developments. It will be a useful reference for fertility specialists with an expertise outside reproductive genetics. LARGE SCALE DATA: none. STUDY FUNDING AND COMPETING INTERESTS: No specific funding was obtained to conduct this questionnaire.

Chromosome fragility at FRAXA in human cleavage stage embryos at risk for fragile X syndrome.

Fragile X syndrome (FXS), the most common inherited intellectual disability syndrome, is caused by expansion and hypermethylation of the CGG repeat in the 5' UTR of the FMR1 gene. This expanded repeat, also known as the rare fragile site FRAXA, causes X chromosome fragility in cultured cells from patients but only when induced by perturbing pyrimidine synthesis. We performed preimplantation genetic diagnosis (PGD) on 595 blastomeres biopsied from 442 cleavage stage embryos at risk for FXS using short tandem repeat (STR) markers. In six blastomeres, from five embryos an incomplete haplotype was observed with loss of all alleles telomeric to the CGG repeat. In all five embryos, the incomplete haplotype corresponded to the haplotype carrying the CGG repeat expansion. Subsequent analysis of additional blastomeres from three embryos by array comparative genomic hybridization (aCGH) confirmed the presence of a terminal deletion with a breakpoint close to the CGG repeat in two blastomeres from one embryo. A blastomere from another embryo showed the complementary duplication. We conclude that a CGG repeat expansion at FRAXA causes X chromosome fragility in early human IVF embryos at risk for FXS.

Intracytoplasmic morphologically selected sperm injection (IMSI): a critical and evidence-based review.

Introduced in 2001, intracytoplasmic morphologically selected sperm injection (IMSI) represents a more sophisticated way of ICSI whereby, prior to injection, the spermatozoon is selected at higher magnification. Doing so, the spermatozoon can be evaluated for fine integrity of its nucleus and the injection of a normal spermatozoon with a vacuole-free head can be assured. Additional research is needed to unravel the underlying mechanisms responsible for the presence of vacuoles in sperm heads. Associations with acrosome status, chromatin condensation, DNA fragmentation and sperm aneuploidy have been documented, however, controversy on their nature exists. Spermatozoon shape and large vacuoles are detected and deselected in conventional ICSI as well. However, the detection of subtle small vacuoles depends on the resolving power of the optical system and may impact oocyte fertilization, embryo development and implantation. Several comparative studies have indicated that the use of high-magnification sperm selection was associated with both higher pregnancy and delivery rates, whereas also lower miscarriage rates were observed. However, still to date randomized, well-powered studies to confirm these findings are scarce and show conflicting results. Hence, the most relevant indications for IMSI still remain to be determined. Two groups of patients have been put forward i.e. severe male-factor infertility patients and patients with a history of repeated ICSI failures. However, for both groups limited to no proof of any benefit does exist. IMSI is a time-consuming procedure at the expense of oocyte ageing. The lack of proof and understanding of its benefit does not justify its routine clinical application at present.

No relationship between the type of pituitary suppression for IVF and chromosomal abnormality rates of blastomeres: an observational study.

OBJECTIVE: To investigate whether the incidence of chromosomally abnormal blastomeres is related to the type of pituitary suppression used in ovarian stimulation. DESIGN: Retrospective study. SETTING: Tertiary referral center. PATIENT(S): The study involved 694 consecutive cycles; 320 belonged to agonist group and 374 to antagonist group, of patients' ≤ 37 years of age who underwent preimplantation genetic screening between October 1, 1992 until December 31, 2006. All of them (and their partners) had normal karyotyping results. Only the data of patients who had at least one embryo biopsy were analyzed. INTERVENTION(S): Preimplantation genetic screening (PGS). MAIN OUTCOME MEASURE(S): The primary outcome measure was detection of abnormal blastomeres on the total number of embryos analyzed. RESULT(S): The total abnormal ratio was statistically similar between the embryos of the two study groups (49.9 ± 28.1 vs. 50.2 ± 26.6). Likewise, a multivariate (linear regression) analysis indicated that the total abnormality ratio was not influenced by the type of stimulation when simultaneously adjusting for age, rank of trials, indication for preimplantation genetic screening, total gonadotropin amount, number of cumulus-oocyte complexes, and number of two pronuclear oocytes embryos. No difference was observed in ongoing pregnancy rates between agonists and antagonists (26.6% vs. 23.3%, respectively). CONCLUSION(S): Based on our findings there is no difference in the proportion of abnormal blastomeres either when using gonadotropin-releasing hormone (GnRH) agonist, or antagonist protocol.

Two-year auxological and medical outcome of singletons born after embryo biopsy applied in preimplantation genetic diagnosis or preimplantation genetic screening.

BACKGROUND: Embryo biopsy is an essential but invasive procedure to perform preimplantation genetic diagnosis (PGD) or preimplantation genetic screening (PGS). The major objective of this study was to determine whether embryo biopsy might cause post-natal growth restriction. METHODS: We compared growth data and physical findings at birth and 2 years for singletons born either after PGD/PGS (n = 70), ICSI (n = 70) or natural conception (NC) (n = 70). Children were matched for gender, maternal educational level, mother tongue and birth order. RESULTS: No significant differences were found between the three groups regarding weight, height and head circumference standard deviation scores (SDS) at birth and at age 2 years, although the PGD/PGS children tended to have a lower birthweight compared with the NC children. At 2 years, the mean BMI SDS in PGD/PGS children was significantly lower compared with NC children (P = 0.005). PGD/PGS children were more frequently born after Caesarian section than ICSI children, but had no more congenital malformations, hospital admissions and surgical interventions compared with ICSI and NC children. CONCLUSIONS: Singleton children at age 2 years born after embryo biopsy applied in PGD/PGS present a similar post-natal linear growth compared with ICSI and NC children. PGD/PGS singletons appear not to be at higher risk for congenital malformations and surgical interventions during the first 2 years of life. To date, there have been no observable detrimental effects of the PGD/PGS procedure on children.

Prospectively randomized controlled trial of PGS in IVF/ICSI patients with poor implantation.

This randomized, controlled trial verifies whether patients with recurrent failed implantation benefit from preimplantation genetic diagnosis for aneuploidy, as compared with conventional assisted reproduction treatment procedures. Two hundred patients with recurrent failed implantation were randomized into two groups. A total of 139 patients underwent ovarian stimulation, and preimplantation genetic screening was performed in 72 patients. Analysis of chromosomes X, Y, 13, 16, 18, 21 and 22 was carried out using fluorescence in-situ hybridization in blastomeres of day-3 cleavage-stage embryos in the study group. The primary endpoint was implantation rate. Secondary endpoints were embryonic morphology and chromosomal status, number of transferred embryos and clinical pregnancy rate. With regard to the implantation rate, there was no significant difference between the study group (21.4%) and the control group (25.3%). The number of embryos transferred was significantly lower in the study group, namely 1.4 (SD 1.0) versus 2.1 (SD 1.0) in the control group (P < 0.05). The clinical pregnancy rate was not significantly different between the groups (25.0% in the study group versus 40.3% in the control group). It can be concluded that preimplantation genetic screening does not increase the implantation rates after IVF-intracytoplasmic sperm injection in women with repeated implantation failure.

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.

Blastocyst formation in in vitro fertilization versus intracytoplasmic sperm injection cycles: influence of the fertilization procedure.

OBJECTIVE: To compare the quality of early cleaving embryos and blastocysts obtained by IVF or intracytoplasmic sperm injection (ICSI). DESIGN: Retrospective study. SETTING: Tertiary infertility center. PATIENT(S): Sibling oocytes of 104 patients in 104 IVF vs. ICSI cycles. INTERVENTION(S): Cumulus oocyte complexes (n = 1,358) were randomly subjected to ICSI or IVF. MAIN OUTCOME MEASURE(S): Embryo development and blastocyst formation rate. The blastocyst quality and cycle efficiency were also evaluated. RESULT(S): Early embryo cleavage was higher after ICSI (37.1%) compared to IVF (14.1%). The percentage of > or =4-cell embryos on day 2 and > or =8-cell embryos on day 3 was similar for both procedures. The overall blastocyst formation was not different between ICSI (50.2%) and IVF (54.8%), neither was the percentage of good-quality blastocysts (31.3% for ICSI and 36.0% for IVF). The total cycle efficiency (percentage of embryos transferred and frozen per two pronuclei [2PN]) was comparable for the two techniques (51.7% for ICSI and 57.4% for IVF). CONCLUSION(S): No differences were found on sibling oocytes in the embryo development and blastocyst formation, irrespective of the fertilization procedure. Earlier suggestions that the ICSI technique may result in impaired blastocyst development were not confirmed in this study.

Comparison of transfers to Fallopian tubes or uterus after ICSI.

The aim of this study was to compare the implantation rate of tubal-replaced microinjected oocytes (MIFT) versus conventional day 2 intrauterine embryo transfer in patients undergoing intracytoplasmic sperm injection (ICSI). Sixty-three patients in need of ICSI, between 18 and 37 years of age with normal menstrual cycles and fewer than four previous ICSI attempts, were randomized between April 1999 and December 2001. In the MIFT group, up to three micro-injected oocytes were transferred laparoscopically 4 h after microinjection. In the ICSI-embryo transfer group, up to three cleaving embryos were replaced into the uterine cavity 48 h after insemination. Fifty-nine patients reached the stage of oocyte retrieval; 31 patients had a day 2 embryo transfer and 28 patients had MIFT. The ongoing clinical pregnancy and implantation rate (i.e. the total number of gestational sacs with fetal heartbeat divided by the total number of transferred embryos or micro-injected oocytes) was 35 and 24% in the ICSI-embryo transfer group and 29 and 11% in the MIFT group respectively. In conclusion, this study shows a significant decrease in implantation rate in the MIFT group (P < 0.05). In this group of patients there seems to be no advantage to tubal replacement of micro-injected oocytes.

Influence of individual sperm morphology on fertilization, embryo morphology, and pregnancy outcome of intracytoplasmic sperm injection.

OBJECTIVE: To evaluate the influence of morphology of individual spermatozoa on fertilization and pregnancy outcome. DESIGN: Retrospective analysis. SETTING: An IVF center in an institutional research environment. PATIENT(S): Fertilization and embryo quality according to individual sperm morphology were analyzed in 662 consecutive ICSI cycles. Pregnancy outcome was evaluated for these cycles and an additional 1005 consecutive ICSI cycles. INTERVENTION(S): ICSI was performed using sperm cells of ejaculated, epididymal, or testicular origin. Observation through an inverted microscope was used to prospectively classify injected sperm cells as normal or morphologically abnormal. MAIN OUTCOME MEASURE(S): Oocyte fertilization, embryo morphology, and pregnancy outcome of unmixed embryo transfers. RESULT(S): Injection of morphologically abnormal spermatozoa (irrespective of origin) resulted in a lower fertilization rate (60.7%) than did injection of morphologically normal spermatozoa (71.7%). Embryo cleavage quality did not differ between groups. Higher pregnancy and implantation rates were obtained in patients with normal sperm morphology (36.7% and 18.7%, respectively) than in those with abnormal sperm morphology (20.2% and 9.6%). CONCLUSION(S): Individual sperm morphology assessed at the moment of ICSI correlated well with fertilization outcome but did not affect embryo development. The implantation rate was lower when only embryos resulting from injection of an abnormal spermatozoon were available.

Glucose-regulated gene expression maintaining the glucose-responsive state of beta-cells.

The mammalian beta-cell has particular properties that synthesize, store, and secrete insulin in quantities that are matched to the physiological demands of the organism. To achieve this task, beta-cells are regulated both acutely and chronically by the extracellular glucose concentration. Several in vivo and in vitro studies indicate that preservation of the glucose-responsive state of beta-cells is lost when the extracellular glucose concentration chronically deviates from the normal physiological condition. Experiments with the protein synthesis inhibitor cycloheximide suggest that the maintenance of the functional state of beta-cells depends on protein(s) with rapid turnover. Analysis of newly synthesized proteins via two-dimensional gel electrophoresis and high-density gene expression microarrays demonstrates that the glucose-dependent preservation of beta-cell function is correlated with glucose regulation of a large number of beta-cell genes. Two different microarray analyses of glucose regulation of the mRNA profile in beta-cells show that the sugar influences expression of multiple genes involved in energy metabolism, the regulated insulin biosynthetic/secretory pathway, membrane transport, intracellular signaling, gene transcription, and protein synthesis/degradation. Functional analysis of some of these regulated gene clusters has provided new evidence for the concept that cataplerosis, the conversion of mitochondrial metabolites into lipid intermediates, is a major metabolic pathway that allows beta-cell activation independently of closure of ATP-sensitive potassium channels.