Cryopreservation of human embryos and its contribution to in vitro fertilization success rates

Prenatal growth trajectories and birth outcomes after frozen-thawed extended culture embryo transfer and fresh embryo transfer: the Rotterdam Periconception Cohort

RESEARCH QUESTION

Are there differences in prenatal growth trajectories and birth outcomes between singleton pregnancies conceived after IVF treatment with frozen-thawed extended culture embryo transfer at day 5, fresh embryo transfer at day 3 or naturally conceived pregnancies?

DESIGN

From a prospective hospital-based cohort, 859 singleton pregnancies were selected, including 133 conceived after IVF with frozen-thawed embryo transfer, 276 after fresh embryo transfer, and 450 naturally conceived pregnancies. Longitudinal 3D ultrasound scans were performed at 7, 9 and 11 weeks of gestation for offline crown-rump length (CRL) and embryonic volume measurements. Second trimester estimated fetal weight was based on growth parameters obtained during the routine fetal anomaly scan at 20 weeks of gestation. Birth outcome data were collected from medical records.

RESULTS

No differences regarding embryonic growth trajectories were observed between frozen-thawed and fresh embryo transfer. Birthweight percentiles after fresh embryo transfer were lower than after frozen-thawed embryo transfer (38.0 versus 48.0; P = 0.046, respectively). The prevalence of non-iatrogenic preterm birth (PTB) was significantly lower in pregnancies resulting from fresh embryo transfer compared with frozen-thawed embryo transfer (4.7% versus 10.9%; P = 0.026, respectively). Compared with naturally conceived pregnancies, birthweight percentiles and percentage of non-iatrogenic PTB were significantly lower in pregnancies after fresh embryo transfer and gestational age at birth was significantly higher.

CONCLUSIONS

This study shows that embryonic growth is comparable between singleton pregnancies conceived after fresh and frozen-thawed embryo transfer. The lower relative birthweight and PTB rate in pregnancies after fresh embryo transfer than after frozen-thawed embryo transfer and naturally conceived pregnancies warrants further investigation.

A systematic review of clinical efficacy of frozen-thawed embryos and fresh embryos in in-vitro fertilization cycles

BACKGROUND

Frozen-thawed embryo (FTE) and fresh embryo (FE) transfer are two common strategies in vitro fertilization (IVF), while the results and findings still vary among studies.

METHODS

We searched multiple databases for relevant studies comparing the clinical effects of FTE and FE. Meta-analyses were conducted with Review Manager 5.0 to assess the efficacy among included articles. We also analyzed the risk of bias for the reports.

RESULTS

Nine studies eventually met the inclusion criteria from 2010 to 2018, and 11396 patients were included. The meta-analyses indicated no significant difference in biochemical pregnancy, clinical pregnancy and ongoing pregnancy rates. Meanwhile, the implantation rate and live birth rate in frozen-thawed embryos were much higher than those of fresh embryo. The birth weight in the frozen-thawed ET group was greater than that of the FE group, and the low birth weight rate in FTE was lower than FE group.

CONCLUSION

Our findings suggested a trend toward favouring frozen-thawed FTE might be a preferred transfer strategy for patients with IVF.

Creation of a Bioengineered Ovary: Isolation of Female Germline Stem Cells for the Repopulation of a Decellularized Ovarian Bioscaffold

Ovarian failure is the most common cause of infertility and affects about 1% of young women. One innovative strategy to restore ovarian function may be represented by the development of a bioprosthetic ovary, obtained through the combination of tissue engineering and regenerative medicine.We here describe the two main steps required for bioengineering the ovary and for its ex vivo functional reassembling. The first step aims at producing a 3D bioscaffold, which mimics the natural ovarian milieu in vitro. This is obtained with a whole organ decellularization technique that allows the maintenance of microarchitecture and biological signals of the original tissue. The second step involves the use of magnetic activated cell sorting (MACS) to isolate purified female germline stem cells (FGSCs). These cells are able to differentiate in ovarian adult mature cells, when subjected to specific stimuli, and can be used them to repopulate ovarian decellularized bioscaffolds. The combination of the two techniques represents a powerful tool for in vitro recreation of a bioengineered ovary that may constitute a promising solution for hormone and fertility function restoring. In addition, the procedures here described allow for the creation of a suitable 3D platform with useful applications both in toxicological and transplantation studies.

Fertility outcomes in women after controlled ovarian stimulation with gonadotropin releasing hormone agonist long protocol: fresh versus frozen embryo transfer

Background

Along with progress in embryo cryopreservation, especially the vitrification, freeze all strategy has become more acceptable than ever. Some studies have found comparable or higher live birth rate with frozen embryo transfer (FET) than with fresh embryo transfer(ET)in gonadotropin releasing hormone antagonist (GnRH-ant) protocol. However from our literature research, there have been no reports about live birth rate comparison between fresh ET and FET with gonadotropin releasing hormone agonist (GnRH-a) long protocol. The aim of this study is to retrospectively investigate whether patients benefit from freeze all strategy in GnRH-a protocol using real-world data.

Methods

This is a retrospective cohort study, in which women undergoing fresh ET or FET with GnRH-a long protocol at Chongqing Reproductive and Genetics Institute from January 2016 to December 2018 were evaluated. The primary outcome was live birth rate. The secondary outcomes were implantation rate, clinical pregnancy rate, pregnancy loss and ectopic pregnancy rate.

Results

A total of 7,814 patients met inclusion criteria, implementing 5,216 fresh ET cycles and 2,598 FET cycles, respectively. The demographic characteristics of the patients were significantly different between fresh ET and FET groups, except BMI. After controlling for a broad range of potential confounders including age, infertility duration, BMI, AMH, number of oocytes retrieved and of available embryos, multivariate logistic regression analysis demonstrated that there was no significant difference in clinical pregnancy rate, ectopic pregnancy rate and pregnancy loss rate between two groups (all P > 0.05). However, the implantation rate and live birth rate in fresh ET group were significantly higher than FET group (P < 0.001 and P = 0.012, respectively).

Conclusions

Under GnRH-a long protocol, compared to FET, fresh ET was associated with higher implantation rate and live birth rate in infertile patients that underwent in vitro fertilization (IVF). The freeze all strategy should be individualized and made with caution especially with GnRH-a long protocol.

A qualitative study on couples' attitudes and concerns regarding a freeze all strategy in ART treatment

The freeze all strategy has become a promising alternative to fresh embryo transfer in fertility treatment almost eliminating late ovarian hyperstimulation syndrome (OHSS) in the segmented cycle. There is a lack of in-depth knowledge regarding patients' attitudes towards the freeze all strategy. The aim of this study was to explore the attitudes towards a freeze all strategy compared with fresh embryo transfer in assisted reproductive technology (ART) treatment among couples in a public health care setting. We conducted semi-structured qualitative interviews with ten couples already participants in a randomised controlled trial (RCT) and undergoing ART treatment. The couple's responses showed five themes: (i) Starting treatment provides needed relief; (ii) Treatment must be provided with humanity; (iii) Provision of information instigates positive attitudes towards treatment; (iv) Fresh treatment - 'The normal way'; and (v) Freeze all treatment - 'The new black'. When thorough information about treatment procedures and safety aspects regarding both the freeze all and fresh embryo transfer strategy is given prior to initiation of treatment, couples feel secure and content, regardless of which treatment strategy is finally applied. This qualitative study found that starting treatment could prompt longed-for relief, as professionals would now 'take over' and assist in meeting the couple's family building goals.

Fertility technologies and how to optimize laboratory performance to support the shortening of time to birth of a healthy singleton: a Delphi consensus

PURPOSE

To explore how the assisted reproductive technology (ART) laboratories can be optimized and standardized to enhance embryo culture and selection, to bridge the gap between standard practice and the new concept of shortening time to healthy singleton birth.

METHODS

A Delphi consensus was conducted (January to July 2018) to assess how the ART laboratory could be optimized, in conjunction with existing guidelines, to reduce the time to a healthy singleton birth. Eight experts plus the coordinator discussed and refined statements proposed by the coordinator. The statements were distributed via an online survey to 29 participants (including the eight experts from step 1), who voted on their agreement/disagreement with each statement. Consensus was reached if ≥ 66% of participants agreed/disagreed with a statement. If consensus was not achieved for any statement, that statement was revised and the process repeated until consensus was achieved. Details of statements achieving consensus were communicated to the participants.

RESULTS

Consensus was achieved for all 13 statements, which underlined the need for professional guidelines and standardization of lab processes to increase laboratory competency and quality. The most important points identified were the improvement of embryo culture and embryo assessment to shorten time to live birth through the availability of more high-quality embryos, priority selection of the most viable embryos and improved cryosurvival.

CONCLUSION

The efficiency of the ART laboratory can be improved through professional guidelines on standardized practices and optimized embryo culture environment, assessment, selection and cryopreservation methodologies, thereby reducing the time to a healthy singleton delivery.

The Appraisal of Body Content (ABC) trial: Increased male or female adiposity does not significantly impact in vitro fertilization laboratory or clinical outcomes

OBJECTIVE

To investigate the impact of obesity as determined by bioelectric impedance analysis (BIA) and body mass index (BMI) on in vitro fertilization (IVF) laboratory and clinical outcomes.

DESIGN

Prospective cohort study.

SETTING

Academic-affiliated private practice.

PATIENT(S)

A total of 1,889 infertile couples undergoing IVF from June 2016 to January 2019.

INTERVENTION(S)

Female patients and male partners underwent BIA and BMI measurement at the time of oocyte retrieval. Embryology and clinical outcomes were prospectively tracked with comparison groups determined by percentage of body fat (%BF) and BMI categories.

MAIN OUTCOME MEASURE(S)

Fertilization rate, blastocyst formation rate, euploidy rate, miscarriage rate, sustained implantation rate, live birth rate, rates of low birth weight/very low birth weight, prematurity rates.

RESULT(S)

Fertilization rates and euploidy rates were equivalent among all women. Blastocyst formation rates were slightly higher (55%) in women with an obese %BF compared with all other %BF categories (51%); however, this trend was not noted in women defined as obese by BMI. Miscarriage rates, sustained implantation rates, and live birth rates were equivalent among all women. The rate of very low birth weight was low but increased in obese women (3%) versus underweight, normal-weight, and overweight counterparts (0%-1.3%) as determined by %BF and BMI. Obesity in men did not significantly affect any embryologic or clinical outcomes.

CONCLUSION(S)

Although maternal obesity imposes a small but increased risk of very low birth weight infants, most embryology and pregnancy outcomes are equivalent to normal weight patients. Paternal obesity does not appear to affect IVF, pregnancy, or delivery outcomes.

Fresh versus frozen embryo transfers in assisted reproduction

BACKGROUND

In vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI) treatments conventionally consist of a fresh embryo transfer, possibly followed by one or more cryopreserved embryo transfers in subsequent cycles. An alternative option is to freeze all suitable embryos and transfer cryopreserved embryos in subsequent cycles only, which is known as the 'freeze all' strategy. This is the first update of the Cochrane Review on this comparison.

OBJECTIVES

To evaluate the effectiveness and safety of the freeze all strategy compared to the conventional IVF/ICSI strategy in women undergoing assisted reproductive technology.

SEARCH METHODS

We searched the Cochrane Gynaecology and Fertility Group Trials Register, CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL, and two registers of ongoing trials from inception until 23 September 2020 for relevant studies, checked references of publications found, and contacted study authors to obtain additional data.

SELECTION CRITERIA

Two review authors (TZ and MZ) independently selected studies for inclusion, assessed risk of bias, and extracted study data. We included randomised controlled trials comparing a 'freeze all' strategy with a conventional IVF/ICSI strategy including a fresh embryo transfer in women undergoing IVF or ICSI treatment.

DATA COLLECTION AND ANALYSIS

The primary outcomes were cumulative live birth rate and ovarian hyperstimulation syndrome (OHSS). Secondary outcomes included effectiveness outcomes (including ongoing pregnancy rate and clinical pregnancy rate), time to pregnancy and obstetric, perinatal and neonatal outcomes.

MAIN RESULTS

We included 15 studies in the systematic review and eight studies with a total of 4712 women in the meta-analysis. The overall evidence was of moderate to low quality. We graded all the outcomes and downgraded due to serious risk of bias, serious imprecision and serious unexplained heterogeneity. Risk of bias was associated with unclear blinding of investigators for preliminary outcomes of the study during the interim analysis, unit of analysis error, and absence of adequate study termination rules. There was an absence of high-quality evidence according to GRADE assessments for our primary outcomes, which is reflected in the cautious language below. There is probably little or no difference in cumulative live birth rate between the 'freeze all' strategy and the conventional IVF/ICSI strategy (odds ratio (OR) 1.08, 95% CI 0.95 to 1.22; I2 = 0%; 8 RCTs, 4712 women; moderate-quality evidence). This suggests that for a cumulative live birth rate of 58% following the conventional strategy, the cumulative live birth rate following the 'freeze all' strategy would be between 57% and 63%. Women might develop less OHSS after the 'freeze all' strategy compared to the conventional IVF/ICSI strategy (OR 0.26, 95% CI 0.17 to 0.39; I2 = 0%; 6 RCTs, 4478 women; low-quality evidence). These data suggest that for an OHSS rate of 3% following the conventional strategy, the rate following the 'freeze all' strategy would be 1%. There is probably little or no difference between the two strategies in the cumulative ongoing pregnancy rate (OR 0.95, 95% CI 0.75 to 1.19; I2 = 31%; 4 RCTs, 1245 women; moderate-quality evidence).  We could not analyse time to pregnancy; by design, time to pregnancy is shorter in the conventional strategy than in the 'freeze all' strategy when the cumulative live birth rate is comparable, as embryo transfer is delayed in a 'freeze all' strategy. We are uncertain whether the two strategies differ in cumulative miscarriage rate because the evidence is very low quality (Peto OR 1.06, 95% CI 0.72 to 1.55; I2 = 55%; 2 RCTs, 986 women; very low-quality evidence) and cumulative multiple-pregnancy rate (Peto OR 0.88, 95% CI 0.61 to 1.25; I2 = 63%; 2 RCTs, 986 women; very low-quality evidence). The risk of hypertensive disorders of pregnancy (Peto OR 2.15, 95% CI 1.42 to 3.25; I2 = 29%; 3 RCTs, 3940 women; low-quality evidence), having a large-for-gestational-age baby (Peto OR 1.96, 95% CI 1.51 to 2.55; I2 = 0%; 3 RCTs, 3940 women; low-quality evidence) and a higher birth weight of the children born (mean difference (MD) 127 g, 95% CI 77.1 to 177.8; I2 = 0%; 5 RCTs, 1607 singletons; moderate-quality evidence) may be increased following the 'freeze all' strategy. We are uncertain whether the two strategies differ in the risk of having a small-for-gestational-age baby because the evidence is low quality (Peto OR 0.82, 95% CI 0.65 to 1.05; I2 = 64%; 3 RCTs, 3940 women; low-quality evidence).

AUTHORS' CONCLUSIONS

We found moderate-quality evidence showing that one strategy is probably not superior to the other in terms of cumulative live birth rate and ongoing pregnancy rate. The risk of OHSS may be decreased in the 'freeze all' strategy. Based on the results of the included studies, we could not analyse time to pregnancy. It is likely to be shorter using a conventional IVF/ICSI strategy with fresh embryo transfer in the case of similar cumulative live birth rate, as embryo transfer is delayed in a 'freeze all' strategy. The risk of maternal hypertensive disorders of pregnancy, of having a large-for-gestational-age baby and a higher birth weight of the children born may be increased following the 'freeze all' strategy. We are uncertain if 'freeze all' strategy reduces the risk of miscarriage, multiple pregnancy rate or having a small-for-gestational-age baby compared to conventional IVF/ICSI.

Comparing the cumulative live birth rate of cleavage-stage versus blastocyst-stage embryo transfers between IVF cycles: a study protocol for a multicentre randomised controlled superiority trial (the ToF trial)

INTRODUCTION

In vitro fertilisation (IVF) has evolved as an intervention of choice to help couples with infertility to conceive. In the last decade, a strategy change in the day of embryo transfer has been developed. Many IVF centres choose nowadays to transfer at later stages of embryo development, for example, transferring embryos at blastocyst stage instead of cleavage stage. However, it still is not known which embryo transfer policy in IVF is more efficient in terms of cumulative live birth rate (cLBR), following a fresh and the subsequent frozen-thawed transfers after one oocyte retrieval. Furthermore, studies reporting on obstetric and neonatal outcomes from both transfer policies are limited.

METHODS AND ANALYSIS

We have set up a multicentre randomised superiority trial in the Netherlands, named the Three or Fivetrial. We plan to include 1200 women with an indication for IVF with at least four embryos available on day 2 after the oocyte retrieval. Women are randomly allocated to either (1) control group: embryo transfer on day 3 and cryopreservation of supernumerary good-quality embryos on day 3 or 4, or (2) intervention group: embryo transfer on day 5 and cryopreservation of supernumerary good-quality embryos on day 5 or 6. The primary outcome is the cLBR per oocyte retrieval. Secondary outcomes include LBR following fresh transfer, multiple pregnancy rate and time until pregnancy leading a live birth. We will also assess the obstetric and neonatal outcomes, costs and patients' treatment burden.

ETHICS AND DISSEMINATION

The study protocol has been approved by the Central Committee on Research involving Human Subjects in the Netherlands in June 2018 (CCMO NL 64060.000.18). The results of this trial will be submitted for publication in international peer-reviewed and in open access journals.

TRIAL REGISTRATION NUMBER

Netherlands Trial Register (NL 6857).

Mitochondrial DNA in Fresh versus Frozen Embryo Culture Media of Polycystic Ovarian Syndrome Patients Undergoing Invitro Fertilization: A Possible Predictive Marker of a Successful Pregnancy

Purpose

Frozen embryos transfer (ET) may improve the live-birth and reduce rates of ovarian hyperstimulation in polycystic ovary syndrome (PCOS) patients. Morphological criteria are the classical way for embryo selection, yet recently, many biochemical and genetic markers have been developed. This study aimed to compare fresh and frozen ET using the mtDNA/gDNA ratio of embryo secretome and the possibility of using this ratio as a predictive marker of PCOS pregnancy rate.

Subjects and Methods

One hundred PCOS patients undergoing IVF were chosen according to Rotterdam criteria and divided into two groups. Group I (50 with fresh ET), group II (50 with frozen ET), and otherwise 33 apparently healthy women as a control group with fresh ET. We then carried out absolute quantification of embryo culture media mtDNA and gDNA by real-time PCR.

Results

mtDNA/gDNA ratio was significantly low in PCOS embryo culture media in comparison with control. Additionally, while the mtDNA/gDNA ratio was significantly high in pregnant PCOS embryo culture media, it was high, though not statistically significant, in the fresh ET than frozen ET group. mtDNA/gDNA ratio sensitivity and specificity in PCOS embryo culture media as a predictive value of pregnancy rate were (86% and 96%, respectively).

Conclusion

mtDNA/gDNA ratio measurement in PCOS embryo culture media is a novel marker that can be clinically applied as a predictive value of the quality of the morphologically good embryo.

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Prediction of live birth probability after in vitro fertilization and intracytoplasmic sperm injection treatment: A multi-center retrospective study in Chinese population

AIM

To develop a prediction model to estimate the chances of live birth over multiple cycles of in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) treatment.

METHODS

A retrospective cohort study was launched in three reproductive centers including 10 824 couples who received 14 106 treatment cycles with known pregnancy outcomes by the end of 2016. Discrete time logistic regression was used to establish the model and a nomogram was developed to predict the chance of live birth on plain paper-based final predictors.

RESULTS

Among 10 824 couples, 5809 (53.7%) ended up with a live birth with several successive transplant cycles. What's more, we found that younger female age (p < 0.001), smaller cycle number (p < 0.001), female body mass index (p < 0.001), male factor (p < 0.001), ovulation disorder (p = 0.006), and higher endometrial thickness (p < 0.001) were significantly associated with increased live birth rate. Discrimination of the model expressed by area under the curve (AUC) was 0.66.

CONCLUSION

Our study will help shape couples' expectations of their ART outcome, allowing them to plan their treatments more efficiently and prepare emotionally and financially.

A Comparison of the Efficacy of Immediate Versus Delayed Frozen-Thawed Embryo Transfer on the Ongoing Pregnancy Rate After a Failed IVF Attempt: Study Protocol for a Randomized, Non-Inferiority, Parallel-Group, Controlled Trial

INTRODUCTION

In clinical practice, the ideal time at which to perform a Frozen-thawed Embryo Transfer (FET) after a failed In-vitro Fertilization-embryo Transfer (IVF-ET) is still unclear to most practicing physicians. In addition, physicians often delay the introduction of FET due to concerns on the possible residual effects of ovarian hyperstimulation, which may interfere with the regular menstrual cycle. Moreover, given that most of the published studies on the topic are retrospective with contradictory findings, it is crucial to provide evidence-based randomized control guides for clinical practice.

METHODS/ANALYSIS

The study is a randomized, non-inferiority, parallel-group, controlled trial that will enroll a total of 732 women undergoing their first FET after a failed fresh embryo transfer (ET) cycle. The participants will then be randomized into two groups based on a computer-generated randomized list. The two groups include: (i) an immediate group were FET will be carried out during the first menstrual cycle after a failed fresh ET cycle and (ii) a delayed group where FET will be carried out during the second menstrual cycle after a failed fresh ET cycle. Primary outcomes will be defined as viable pregnancies with fetal heartbeats, diagnosed through pelvic ultrasonography after twelve weeks of gestation.

ETHICS AND DISSEMINATION

The study was approved by the Ethics Committee of the Assisted Reproductive Medicine at the Affiliated Hospital of Shandong University of Traditional Chinese Medicine (SDTCM/E-2020.2.01). In addition, written informed consent will be obtained from all the participants before the study. The results of this trial will be disseminated in a peer-reviewed journal.

DISCUSSION

Currently, there is no consensus with regard to the duration after which the effects of ovarian stimulation are observed after a failed fresh ET and the optimal time required to begin FET. Moreover, no randomized controlled trial exists that compares the ongoing pregnancy rates after immediate versus delayed FET following a failed fresh ET cycle. Therefore, it is important to conduct a well-designed randomized trial to determine whether it is necessary to delay FET for at least one menstrual cycle after the failure of fresh ET.

CLINICAL TRIAL REGISTRATION

ChiCTR2000033313 (http://www.chictr.org.cn/enIndex.aspx).

Effect of vitrification on global gene expression dynamics of bovine elongating embryos

Embryo vitrification involves exposure to high concentrations of cryoprotectants and osmotic stress during cooling and warming in the cryopreservation process. Many of these factors can potentially affect gene expression. In this study, invitro-produced bovine embryos at the blastocyst stage were subjected to vitrification. Four recipients each were used for transferring non-vitrified (n=80) and vitrified (n=80) embryos. A total of 12 non-vitrified and 9 vitrified viable day-14 (D14) embryos were recovered by uterine flushing. RNA-seq analysis of the whole embryo or isolated trophectoderm (TE) from vitrified and fresh recovered D14 embryos revealed a total of 927 and 4376 genes with changed expression in embryos and TE isolates, respectively, as a result of vitrification. In addition, we found 671 and 61 genes commonly up- or downregulated in both vitrified whole embryos and TE. Commonly upregulated pathways by vitrification included epithelial adherens junctions, sirtuin signalling, germ cell-sertoli cell junction, ATM signalling, NER and protein ubiquitination pathways. The commonly downregulated pathways included EIF2 signalling, oxidative phosphorylation, mitochondrial dysfunction, regulation of eIF4 and p70S6K signalling and mTOR signalling pathways. Our analysis identified specific pathways and implicated specific gene expression patterns affecting embryo developmental competence that are important to cryopreservation.

Risk of neurodevelopmental disorders in children born from different ART treatments: a systematic review and meta-analysis

BACKGROUND

Various techniques in assisted reproductive technology (ART) have been developed as solutions for specific infertility problems. It is important to gain consensual conclusions on the actual risks of neurodevelopmental disorders among children who are born from ART. This study aimed to quantify the relative risks of cerebral palsy, intellectual disability, autism spectrum disorder (ASD), and behavioral problems in children from different ART methods by using systematic review and meta-analysis. Healthcare providers could use the results of this study to suggest the suitable ART technique and plan optimum postnatal care.

METHODS

Pubmed, Google Scholar, and Scopus databases were used to search for studies up to January 2020. Of the 181 screened full manuscripts, 17 studies (9.39%) fulfilled the selection criteria. Based on the Newcastle-Ottawa scale ratings, 7 studies were excluded, resulting in 10 studies that were eventually included in the meta-analyses. Mantel-Haenszel risk ratio model was used in the meta-analysis, and the results are described using forest plot with 95% confidence interval. Heterogeneity was assessed using the I² value.

RESULTS

Pooled evaluation of 10 studies showed that the risk of cerebral palsy in children from assisted reproductive technology (ART) is higher than children from natural conceptions (risk ratio [RR] 1.82, [1.41, 2.34]; P = 0.00001). Risk of intellectual disability (RR 1.46, [1.03, 2.08]; P = 0.03) and ASD (RR 1.49 [1.05, 2.11]; P = 0.03) are higher in intracytoplasmic sperm injection (ICSI) children compared to conventional in vitro fertilization (IVF) children. The differences in the risk of neurodevelopmental disorders in children born after frozen and fresh embryo transfers are not significant. Analysis on potential cofounder effects, including multiple birth, preterm birth, and low birth body weight highlight possibilities of significant correlation to the risks of neurodevelopmental disorders.

CONCLUSIONS

Pooled estimates suggest that children born after ART are at higher risk of acquiring cerebral palsy. ICSI treatment causes higher risk of intellectual disability and ASD. These findings suggest the importance of the availability of intensive care unit at the time of delivery and long-term developmental evaluation particularly in children from ICSI.

The freeze-all strategy after IVF: which indications?

The freeze-all strategy is gaining popularity worldwide as an alternative to the conventional fresh embryo transfer. It consists of cryopreservation of the entire embryo cohort and the embryo transfer in a subsequent cycle that takes place separately from ovarian stimulation. The freeze-all strategy was initially a 'rescue' strategy for women at high risk of ovarian hyperstimulation syndrome; however, this approach has been extended to other indications as a scheduled strategy to improve implantation rates. This assumes that ovarian stimulation can alter endometrial receptivity in fresh cycles owing to the effect of supraphysiological levels of steroids on endometrial maturation. The procedure, however, has not been associated with increased live birth rates in all infertile couples, and concerns have been raised about the occurrence of several adverse perinatal outcomes. It is, therefore, crucial to identify in which subgroups of patients a freeze-all strategy could be beneficial. The aim of this review is to summarize current scientific research in this field to highlight potential indications for this strategy and to guide clinicians in their daily practice.

Repeated cryopreservation process impairs embryo implantation potential but does not affect neonatal outcomes

RESEARCH QUESTION

Does repeated cryopreservation process affect embryo implantation potential and neonatal outcomes of human embryos?

DESIGN

This retrospective cohort study was conducted in the Reproductive Medicine Centre, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology. All assisted reproductive technology (ART) cycles were carried out between January 2014 and December 2018. Preferentially matched participants were divided into three groups according to the times of embryo cryopreservation: the fresh group (n = 249), the cryopreservation group (n = 244) and the re-cryopreservation group (n = 216). Embryo implantation rate, live birth rate, miscarriage rate and neonatal complication rate were compared among these three groups.

RESULTS

The embryo implantation rate, clinical pregnancy rate and live birth rate in the re-cryopreservation group were significantly lower, and the miscarriage rate also slightly increased. Logistic regression analysis indicated that embryos with repeated cryopreservation and lower trophectoderm scores were at higher risk of embryo implantation failure in single embryo transfer cycles (OR 1.79 and 1.56, respectively). No significant differences were observed in gender, gestational age, birthweight, neonatal abnormality and neonatal complications among the groups.

CONCLUSIONS

Our findings demonstrate the adverse effect of repeated cryopreservation on embryo implantation potential. The study offers embryologists and reproductive clinicians a warning of detrimental role of repeated cryopreservation. If unnecessary, it is strongly recommended to avoid repeated practice of vitrification and warming on embryos.

Is there a critical LH level for hCG trigger after the detection of LH surge in modified natural frozen-thawed single blastocyst transfer cycles?

Purpose

There is no consensus yet in the literature on an optimal luteinizing hormone (LH) level for human chorionic gonadotrophin (hCG) trigger timing in patients undergoing frozen-thawed embryo transfer (FET) with modified natural cycles (mNC). The objective of our study was to compare the clinical results of hCG trigger at different LH levels in mNC-FET cases.

Methods

This retrospective study was conducted in Istanbul Memorial Hospital ART and Genetics Center. A total of 1076 cases with 1163 mNC-FET cycles were evaluated. LH levels between the start of LH rise (15 IU/L) and LH peak level (> 40 IU/L) were evaluated. Cycles were analyzed in four groups: group A (n = 287) LH level on the day prior to the day of hCG; groups B, C and D, LH levels on the day of hCG: group B (n = 245) LH 15–24.9; group C (n = 253), LH 25–39.9; group D (n = 383) LH ≥ 40. Cycle outcomes in the four groups were compared.

Results

Subgroup analyses of mNC-FET groups showed that implantation, clinical and ongoing pregnancy rates, and pregnancy losses were not significantly different in patients with different LH levels on the day of hCG trigger.

Conclusion

Our study suggests that hCG can be administered at any time between the start of LH rise (≥ 15 IU/L) and LH peak level (≥ 40 IU/L) without a detrimental effect on clinical outcome.

Improving the clinical outcomes by extended culture of day 3 embryos with low blastomere number to blastocyst stage following frozen-thawed embryo transfer

Purpose

This study aimed to investigate whether the extended culture of day 3 (D3) embryos with low blastomere number to blastocyst following frozen–thawed embryo transfer improved the clinical outcomes.

Methods

This was a retrospective study of clinical data of women undergoing in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) cycles in the Tangdu Hospital. The patients were divided into groups with 4–5, 6, 7–9 and > 9 cells based on the blastomere number of D3 embryos. The clinical outcomes were compared.

Results

In fresh transfer cycles, the implantation and clinical pregnancy rates significantly decreased, while the abortion rate significantly increased in the groups with 4–5 and 6 cells compared with those with 7–9 and > 9 cells. In frozen–thawed transfer cycles, the clinical pregnancy and implantation rates for a single blastocyst transfer cycle showed no significant differences in the groups with 4–5 and 6 cells compared with those with 7–9 and > 9 cells. However, the abortion rate was significantly higher in the group with 4–5 cells than in that with 7–9 and > 9 cells. In the double blastocyst transfer cycle, the clinical pregnancy rate showed no significant differences among the groups with 4–5, 6, and 7–9 cells.

Conclusion

The implantation and clinical pregnancy rates of D3 embryos with 6 cells significantly decreased; these embryos were not considered as high-quality embryos. Extended culture of D3 embryos with ≤ 6 blastomeres to blastocysts, particularly 6-cell embryos, resulted in a similar clinical pregnancy rate as that of blastocysts derived from D3 embryos with ≥ 7 blastomeres.

Frozen blastocyst transfer improves the chance of live birth in women with endometrioma

Purpose: The existing literature is scarce regarding outcomes of fresh vs frozen embryo blastocyst transfers in women with endometrioma. The goal of the study was to compare outcomes between fresh and frozen blastocyst transfers (fresh-BT vs. frozen-BT) in endometrioma-affected women. Materials and methods: This study included 315 endometrioma-affected women aged between 20 and 39 years who underwent blastocyst transfer. Primary outcome was live birth rate (an alive birth after 24 completed weeks gestation). Results: The study groups did not differ in terms of patient characteristics and treatment variables. The live birth rate was 40.7% in fresh-BT group and 56.1% in frozen-BT group (OR:1.86, 95% CI:1.18-2.92 p = .007). The approach of frozen embryo transfer was an independent factor of live birth (adjusted OR:1.83, 95% CI:1.16-2.90, p = .009). Conclusion: The approach of frozen blastocyst transfer increases the chance of live birth in endometrioma-affected patients compared with fresh blastocyst transfer. Thus, a frozen embryo transfer may be the choice of strategy in these patients.

Perinatal outcomes of singletons following vitrification versus slow-freezing of embryos: a multicenter cohort study using propensity score analysis

STUDY QUESTION

Is embryo vitrification associated with a higher risk of adverse perinatal outcomes than slow-freezing?

SUMMARY ANSWER

Embryo vitrification was not associated with increased risks of adverse perinatal outcomes of pre-term birth (PTB), low birthweight (LBW), small for gestational age (SGA), large for gestational age (LGA) and macrosomia, as compared to slow-freezing.

WHAT IS KNOWN ALREADY

Vitrification is becoming a widely adopted technology for embryo cryopreservation with higher embryo survival rate and live birth rate than the slow-freezing technique. However, limited data are currently available on risks of adverse perinatal outcomes following vitrification as compared to that of slow-freezing. The impact of vitrification on perinatal outcomes remains further to be elucidated.

STUDY DESIGN, SIZE, DURATION

Six large reproductive medical centers in Guangdong province, Southeast of China, took part in this multicenter retrospective cohort study. Cohorts of 3199 live born singletons after Day 3 frozen-thawed embryo transfer (FET) cycles with either vitrification or slow-freezing between January 2011 and December 2015 were included in the study. Each patient only contributed one cycle per cohort and vanishing twins were excluded. Propensity score (PS) matching was used to control for potential confounding factors.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All live-born singletons following either a vitrified or a slow-frozen cleavage FET cycle during the period from 2011 to 2015 were analyzed. Perinatal outcomes of PTB, LBW, macrosomia, SGA and LGA were compared. The vitrified and slow-frozen cohorts were matched by propensity scores with a 1:1 ratio accounting for potential confounding factors associated with perinatal outcomes. These variables included baseline demographics (maternal age, BMI, education level, parity, type of infertility and cause of infertility), as well as IVF characteristics (insemination method, endometrial preparation protocol and embryo cryopreservation duration).

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 2858 cases from vitrified embryo transfer (ET) and 341 babies from the slow-freezing group were included. After PS matching, 297 pairs of newborns were generated for comparison. The median gestational age was 39 weeks for both cohorts and the birthweights were comparable (3187.7 ± 502.1 g in the vitrified group vs. 3224.6 ± 483.6 in the slow-freezing group, P>0.05). There were no significant differences between the two groups on the incidence of PTB (5.4% vs. 7.7%), LBW (6.7% vs. 5.7%), macrosomia (5.7% vs. 6.1%), SGA (12.5% vs. 8.4%) and LGA (6.4% vs. 8.1%). Parallel logistic regression analysis indicated that vitrification was non-inferior to slow-freezing method in terms of the occurrence of PTB (OR, 0.68 [95% CI, 0.35, 1.31]), LBW (OR, 1.19[0.61-2.32]), macrosomia (OR, 0.94 [0.48-1.86]), SGA (1.55[0.91-2.64]) and LGA (0.78[0.42-1.45]), P>0.05. Sex-stratified PS matching models with multivariable regression analysis further confirmed that vitrification did not increase the risks of above-mentioned adverse perinatal outcomes in either the male or female infant cohort.

LIMITATIONS, REASONS FOR CAUTION

Although the analysis was adjusted for a number of important confounders, the hospital dataset did not contain other potential confounders such as the medical history and obstetrics outcomes of women during pregnancy to allow adjustment. In addition, the current findings are only applicable to cleavage stage FET, but not pronuclei stage or blastocyst stage ET.

WIDER IMPLICATIONS OF THE FINDINGS

Vitrified ET, in comparison with slow-frozen ET, was not associated with increased risks of adverse neonatal outcomes. With its superiority on live birth rates and non-inferiority on safety perinatal outcomes, transition from slow-freezing to the use of vitrification for embryo cryopreservation is reassuring. Nonetheless, future research is needed for the long-term effects of vitrification method on offspring's health outcomes.

STUDY FUNDING/COMPETING INTEREST(S)

The study was funded by the National Key Research and Development Program (2016YFC100205), Guangzhou Science and Technology Project (201804020087), Guangdong Province Science and Technology Project (2016A020218008) and Guangdong Provincial Key Laboratory of Reproductive Medicine (2012A061400003). The authors have no conflicts of interest to declare.

Preimplantation genetic testing for aneuploidies (abnormal number of chromosomes) in in vitro fertilisation

BACKGROUND

In in vitro fertilisation (IVF) with or without intracytoplasmic sperm injection (ICSI), selection of the most competent embryo(s) for transfer is based on morphological criteria. However, many women do not achieve a pregnancy even after 'good quality' embryo transfer. One of the presumed causes is that such morphologically normal embryos have an abnormal number of chromosomes (aneuploidies). Preimplantation genetic testing for aneuploidies (PGT-A), formerly known as preimplantation genetic screening (PGS), was therefore developed as an alternative method to select embryos for transfer in IVF. In PGT-A, the polar body or one or a few cells of the embryo are obtained by biopsy and tested. Only polar bodies and embryos that show a normal number of chromosomes are transferred. The first generation of PGT-A, using cleavage-stage biopsy and fluorescence in situ hybridisation (FISH) for the genetic analysis, was demonstrated to be ineffective in improving live birth rates. Since then, new PGT-A methodologies have been developed that perform the biopsy procedure at other stages of development and use different methods for genetic analysis. Whether or not PGT-A improves IVF outcomes and is beneficial to patients has remained controversial.

OBJECTIVES

To evaluate the effectiveness and safety of PGT-A in women undergoing an IVF treatment.

SEARCH METHODS

We searched the Cochrane Gynaecology and Fertility (CGF) Group Trials Register, CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL, and two trials registers in September 2019 and checked the references of appropriate papers.

SELECTION CRITERIA

All randomised controlled trials (RCTs) reporting data on clinical outcomes in participants undergoing IVF with PGT-A versus IVF without PGT-A were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies for inclusion, assessed risk of bias, and extracted study data. The primary outcome was the cumulative live birth rate (cLBR). Secondary outcomes were live birth rate (LBR) after the first embryo transfer, miscarriage rate, ongoing pregnancy rate, clinical pregnancy rate, multiple pregnancy rate, proportion of women reaching an embryo transfer, and mean number of embryos per transfer.

MAIN RESULTS

We included 13 trials involving 2794 women. The quality of the evidence ranged from low to moderate. The main limitations were imprecision, inconsistency, and risk of publication bias. IVF with PGT-A versus IVF without PGT-A with the use of genome-wide analyses Polar body biopsy One trial used polar body biopsy with array comparative genomic hybridisation (aCGH). It is uncertain whether the addition of PGT-A by polar body biopsy increases the cLBR compared to IVF without PGT-A (odds ratio (OR) 1.05, 95% confidence interval (CI) 0.66 to 1.66, 1 RCT, N = 396, low-quality evidence). The evidence suggests that for the observed cLBR of 24% in the control group, the chance of live birth following the results of one IVF cycle with PGT-A is between 17% and 34%. It is uncertain whether the LBR after the first embryo transfer improves with PGT-A by polar body biopsy (OR 1.10, 95% CI 0.68 to 1.79, 1 RCT, N = 396, low-quality evidence). PGT-A with polar body biopsy may reduce miscarriage rate (OR 0.45, 95% CI 0.23 to 0.88, 1 RCT, N = 396, low-quality evidence). No data on ongoing pregnancy rate were available. The effect of PGT-A by polar body biopsy on improving clinical pregnancy rate is uncertain (OR 0.77, 95% CI 0.50 to 1.16, 1 RCT, N = 396, low-quality evidence). Blastocyst stage biopsy One trial used blastocyst stage biopsy with next-generation sequencing. It is uncertain whether IVF with the addition of PGT-A by blastocyst stage biopsy increases cLBR compared to IVF without PGT-A, since no data were available. It is uncertain if LBR after the first embryo transfer improves with PGT-A with blastocyst stage biopsy (OR 0.93, 95% CI 0.69 to 1.27, 1 RCT, N = 661, low-quality evidence). It is uncertain whether PGT-A with blastocyst stage biopsy reduces miscarriage rate (OR 0.89, 95% CI 0.52 to 1.54, 1 RCT, N = 661, low-quality evidence). No data on ongoing pregnancy rate or clinical pregnancy rate were available. IVF with PGT-A versus IVF without PGT-A with the use of FISH for the genetic analysis Eleven trials were included in this comparison. It is uncertain whether IVF with addition of PGT-A increases cLBR (OR 0.59, 95% CI 0.35 to 1.01, 1 RCT, N = 408, low-quality evidence). The evidence suggests that for the observed average cLBR of 29% in the control group, the chance of live birth following the results of one IVF cycle with PGT-A is between 12% and 29%. PGT-A performed with FISH probably reduces live births after the first transfer compared to the control group (OR 0.62, 95% CI 0.43 to 0.91, 10 RCTs, N = 1680, I² = 54%, moderate-quality evidence). The evidence suggests that for the observed average LBR per first transfer of 31% in the control group, the chance of live birth after the first embryo transfer with PGT-A is between 16% and 29%. There is probably little or no difference in miscarriage rate between PGT-A and the control group (OR 1.03, 95%, CI 0.75 to 1.41; 10 RCTs, N = 1680, I² = 16%; moderate-quality evidence). The addition of PGT-A may reduce ongoing pregnancy rate (OR 0.68, 95% CI 0.51 to 0.90, 5 RCTs, N = 1121, I² = 60%, low-quality evidence) and probably reduces clinical pregnancies (OR 0.60, 95% CI 0.45 to 0.81, 5 RCTs, N = 1131; I² = 0%, moderate-quality evidence).

AUTHORS' CONCLUSIONS

There is insufficient good-quality evidence of a difference in cumulative live birth rate, live birth rate after the first embryo transfer, or miscarriage rate between IVF with and IVF without PGT-A as currently performed. No data were available on ongoing pregnancy rates. The effect of PGT-A on clinical pregnancy rate is uncertain. Women need to be aware that it is uncertain whether PGT-A with the use of genome-wide analyses is an effective addition to IVF, especially in view of the invasiveness and costs involved in PGT-A. PGT-A using FISH for the genetic analysis is probably harmful. The currently available evidence is insufficient to support PGT-A in routine clinical practice.

Randomized controlled open-label study of the effect of vitamin E supplementation on fertility in clomiphene citrate-resistant polycystic ovary syndrome

AIM

To evaluate the effect of vitamin E on ovulation and pregnancy in women with clomiphene citrate (CC)-resistant polycystic ovary syndrome (PCOS).

METHODS

A prospective, randomized, controlled, open label study was conducted on women with CC-resistant PCOS. Patients were randomized, to either control group (n = 30), who received metformin 500 mg thrice daily, in addition to 150 mg/day CC for 5 days starting from day 3 of menstruation for three menstruation cycles, or vitamin E group (n = 30) who received vitamin E 1500 IU/day for the whole study period in addition to metformin and CC with the same previous regimen. The primary outcome was cumulative ovulation rate, while secondary outcomes were pregnancy rate, serum midluteal progesterone, mean follicular diameter, number of dominant follicles and endometrial thickness.

RESULTS

Ovulation was reported in 57 (64.8%) of 88 cycles in the control group and 63 (73.3%) of 86 cycles in the vitamin E group (P = 0.227), while pregnancy was reported in 4 (4.5%) of 88 cycles in the control group and 6 (7%) of 86 cycles in the vitamin E group (P = 0.491).There were nonsignificant differences between groups regarding serum midluteal progesterone, number of dominant follicles and mean follicular diameter. Endometrial thickness was significantly higher in the vitamin E group compared to the control group.

CONCLUSION

The findings of this trial do not support the hypothesis that vitamin E may increase the ovulation and pregnancy rates in women with clomiphene citrate-resistant PCOS.

A freeze-all strategy does not increase live birth rates in women of advanced reproductive age

RESEARCH QUESTION

Does a freeze-all strategy improve live birth rates in women of different age groups?

DESIGN

Retrospective cohort study of 1882 first embryo transfer cycles, performed between January 2013 and December 2015. Reproductive outcomes between fresh (FRESH) or frozen (FROZEN) embryo transfers were compared in patients stratified by age: < 35, between 35 and 38, or > 38 years. Student's t test for independent samples and χ² analyses were used as needed. A multivariable logistic regression analysis was performed adjusting for age, triggering drug, number of retrieved oocytes, number of transferred embryos, and percentage of top-quality embryos.

MAIN RESULTS AND THE ROLE OF CHANCE

Live birth rates (LBR) were significantly higher for FROZEN in the < 35 years group (43.7% vs 24%; p < 0.001). In both the 35-38 and > 38 years groups, LBR for FROZEN vs FRESH were not statistically different (30.9% in the FROZEN group vs 29.3% in the FRESH group, p = 0.70, and 19.8% in the FROZEN group vs 12.7% in the FRESH group, p = 0.07, respectively). The multivariate analysis found a significantly positive effect of performing FROZEN on LBR in the younger group (OR 2.46, 95% CI 1.31-4.62; p = 0.005) but had no impact in women between 35 and 38 years (OR 1.01, 95% CI 0.55-1.83; p = 0.98) or older (OR 0.96, 95% CI 0.43-2.13; p = 0.92).

CONCLUSIONS

Performing a freeze-all strategy seems to result in better reproductive outcomes when compared with a fresh ET in women under 35 years, with no significant impact on older women.

Modified natural protocol seems superior to natural and artificial protocols for preparing the endometrium in frozen embryo transfer cycles

BACKGROUND

Although several studies claim higher success rates in natural cycle (NC) and modified natural cycle (mNC) protocols, currently, there is no consensus on the most effective method of endometrium preparation prior to frozen embryo transfer (FET) cycles. We aimed to find out the best protocol by comparing three different protocols for preparing the endometrium in FET cycles.

METHODS

This retrospective cohort study was conducted at a private in-vitro fertilization (IVF) center. Medical records of all patients enrolled in frozen embryo transfer cycles between November 2017 and February 2019 were reviewed. Group I (N.=94) included patients who underwent artificial endometrial preparation (AC), group II (N.=23) confined patients enrolled in mNC and group III (N.=12) included patients who had NC protocol. Main outcome parameters were clinical pregnancy rates, implantation rates and miscarriage rates.

RESULTS

There was a tendency towards higher clinical pregnancy rate in mNC group. Clinical pregnancy rates of the three groups were 54.3%, 65.2% and 33.3% respectively (P=0.199). Implantation rate was significantly higher in group II (34%, 50% and 12% respectively, P=0.006). Miscarriage rates were similar for the three groups.

CONCLUSIONS

Although not reaching a statistically significant level, there is a tendency towards higher implantation rate and pregnancy rate in mNC protocol compared to true NC and AC protocols.

Cumulative live birth rates in low-prognosis women

STUDY QUESTION

Do cumulative live birth rates (CLBRs) over multiple IVF/ICSI cycles confirm the low prognosis in women stratified according to the POSEIDON criteria?

SUMMARY ANSWER

The CLBR of low-prognosis women is ~56% over 18 months of IVF/ICSI treatment and varies between the POSEIDON groups, which is primarily attributable to the impact of female age.

WHAT IS KNOWN ALREADY

The POSEIDON group recently proposed a new stratification for low-prognosis women in IVF/ICSI treatment, with the aim to define more homogenous populations for clinical trials and stimulate a patient-tailored therapeutic approach. These new criteria combine qualitative and quantitative parameters to create four groups of low-prognosis women with supposedly similar biologic characteristics.

STUDY DESIGN, SIZE, DURATION

This study analyzed the data of a Dutch multicenter observational cohort study including 551 low-prognosis women, aged <44 years, who initiated IVF/ICSI treatment between 2011 and 2014 and were treated with a fixed FSH dose of 150 IU/day in the first treatment cycle.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Low-prognosis women were categorized into one of the POSEIDON groups based on their age (younger or older than 35 years), anti-Müllerian hormone (AMH) level (above or below 0.96 ng/ml), and the ovarian response (poor or suboptimal) in their first cycle of standard stimulation. The primary outcome was the CLBR over multiple complete IVF/ICSI cycles, including all subsequent fresh and frozen-thawed embryo transfers, within 18 months of treatment. Cumulative incidence curves were obtained using an optimistic and a conservative analytic approach.

MAIN RESULTS AND THE ROLE OF CHANCE

The CLBR of the low-prognosis women was on average ~56% over 18 months of IVF/ICSI treatment. Younger unexpected poor (n = 38) and suboptimal (n = 179) responders had a CLBR of ~65% and ~68%, respectively, and younger expected poor responders (n = 65) had a CLBR of ~59%. The CLBR of older unexpected poor (n = 41) and suboptimal responders (n = 102) was ~42% and ~54%, respectively, and of older expected poor responders (n = 126) ~39%. For comparison, the CLBR of younger (n = 164) and older (n = 78) normal responders with an adequate ovarian reserve was ~72% and ~58% over 18 months of treatment, respectively. No large differences were observed in the number of fresh treatment cycles between the POSEIDON groups, with an average of two fresh cycles per woman within 18 months of follow-up.

LIMITATIONS, REASONS FOR CAUTION

Small numbers in some (sub)groups reduced the precision of the estimates. However, our findings provide the first relevant indication of the CLBR of low-prognosis women in the POSEIDON groups. Small FSH dose adjustments between cycles were allowed, inducing therapeutic disparity. Yet, this is in accordance with current daily practice and increases the generalizability of our findings.

WIDER IMPLICATIONS OF THE FINDINGS

The CLBRs vary between the POSEIDON groups. This heterogeneity is primarily determined by a woman's age, reflecting the importance of oocyte quality. In younger women, current IVF/ICSI treatment reaches relatively high CLBR over multiple complete cycles, despite reduced quantitative parameters. In older women, the CLBR remains relatively low over multiple complete cycles, due to the co-occurring decline in quantitative and qualitative parameters. As no effective interventions exist to counteract this decline, clinical management currently relies on proper counselling.

STUDY FUNDING/COMPETING INTEREST(S)

No external funds were obtained for this study. J.A.L. is supported by a Research Fellowship grant and received an unrestricted personal grant from Merck BV. S.C.O., T.C.v.T., and H.L.T. received an unrestricted personal grant from Merck BV. C.B.L. received research grants from Merck, Ferring, and Guerbet. K.F. received unrestricted research grants from Merck Serono, Ferring, and GoodLife. She also received fees for lectures and consultancy from Ferring and GoodLife. A.H. declares that the Department of Obstetrics and Gynaecology, University Medical Centre Groningen received an unrestricted research grant from Ferring Pharmaceuticals BV, the Netherlands. J.S.E.L. has received unrestricted research grants from Ferring, Zon-MW, and The Dutch Heart Association. He also received travel grants and consultancy fees from Danone, Euroscreen, Ferring, AnshLabs, and Titus Healthcare. B.W.J.M. is supported by an National Health and Medical Research Council Practitioner Fellowship (GNT1082548) and reports consultancy work for ObsEva, Merck, and Guerbet. He also received a research grant from Merck BV and travel support from Guerbet. F.J.M.B. received monetary compensation as a member of the external advisory board for Merck Serono (the Netherlands) and Ferring Pharmaceuticals BV (the Netherlands) for advisory work for Gedeon Richter (Belgium) and Roche Diagnostics on automated AMH assay development, and for a research cooperation with Ansh Labs (USA). All other authors have nothing to declare.

TRIAL REGISTRATION NUMBER

Not applicable.

Development of children born from freeze-only versus fresh embryo transfer: follow-up of a randomized controlled trial

OBJECTIVE

To compare the longer-term development outcomes in children born after freeze-only versus fresh embryo transfer (ET) in women with an ovulatory cycle.

DESIGN

Long-term follow-up study (NCT04099784) of babies born alive after the first ET in a randomized controlled trial (RCT) comparing ongoing pregnancy and live birth rates after use of a freeze-only versus fresh ET strategy (NCT02471573).

SETTING

Private clinic.

PATIENT(S)

Of 391 couples randomized to each treatment group in the RCT, 132 (97 singleton/35 twins) and 123 (95 singleton/28 twins) in the freeze-only and fresh ET groups had live birth; 113 parents (86%) from the freeze-only group (147 babies) and 99 (80%) from the fresh ET group (120 babies) returned questionnaires for this follow-up study.

INTERVENTION(S)

Use of a freeze-only or fresh ET strategy after controlled ovarian hyperstimulation with a follicle-stimulating hormone/gonadotropin-releasing antagonist protocol.

MAIN OUTCOME MEASURE(S)

Developmental status at ≥2 years after birth, determined using the Developmental Red Flags and Ages & Stages Third Edition (ASQ-3) Questionnaires.

RESULT(S)

Mean age of children at the end of follow-up was 37 months. Height (95.0 ± 6.1 vs. 95.7 ± 5.6 cm) and weight (14.9 ± 2.6 vs. 14.8 ± 2.6 kg) were similar in the freeze-only and fresh ET groups (results were similar when singletons and twins were analyzed separately). Overall, ASQ-3 scores for problem solving were significantly better in the freeze-only versus fresh ET group (overall: 53.6 ± 8.4 vs. 51.1 ± 10.2), with no significant between-group difference when singletons (52.3 ± 10.1 vs. 51.0 ± 9.9) and twins (55.0 ± 5.5 vs. 51.4 ± 11.1) were analyzed separately. Fine motor skills scores were numerically higher (with P values approaching statistical significance) in the freeze-only versus fresh ET group in the overall analysis (47.8 ± 11.6 vs. 44.9 ± 12.6) and twins (49.85 ± 8.72 vs. 43.93 ± 12.71), but not singletons (46.0 ± 13.4 vs. 45.4 ± 12.6). The overall proportion of children with abnormal ASQ-3 (6.8% vs. 8.3%) or abnormal Red Flags (5.4% vs. 6.7%) findings in the freeze-only and fresh ET groups was low and did not differ significantly between groups.

CONCLUSION(S)

These data provide physicians with additional information on which to base decisions about the relative merits of different approaches to infertility treatment. There do not appear to be any grounds for concern about worse outcomes after use of a freeze-only strategy. However, additional studies comparing childhood development after a freeze-only strategy, fresh ET, and natural cycles are needed before firm conclusions can be drawn.

Preconceptional Maternal Vegetable Intake and Paternal Smoking Are Associated with Pre-implantation Embryo Quality

Inadequate nutrition and lifestyle behaviors, particularly during the periconception period, are associated with a negative impact on embryonic and subsequent fetal development. We investigated the associations between parental nutritional and lifestyle factors and pre-implantation embryo development. A total of 113 women and 41 partners, with a corresponding 490 embryos, who underwent intracytoplasmic sperm injection (ICSI) treatment subscribed to the mHealth coaching platform "Smarter Pregnancy." At baseline, nutrition and lifestyle behaviors (intake of fruits, vegetables, folic acid, and smoking and alcohol use) were identified and risk scores were calculated. A lower risk score represents healthier behavior. As outcome measure, a time-lapse morphokinetic selection algorithm (KIDScore) was used to rank pre-implantation embryo quality on a scale from 1 (poor) to 5 (good) after being cultured in the Embryoscope™ time-lapse incubator until embryonic day 3. To study the association between the nutritional and lifestyle risk scores and the KIDScore in men and women, we used a proportional odds model. In women, the dietary risk score (DRS), a combination of the risk score of fruits, vegetables, and folic acid, was negatively associated with the KIDScore (OR 0.86 (95% CI 0.76 to 0.98), p = 0.02). This could mainly be attributed to an inadequate vegetable intake (OR 0.76 (95% CI 0.59 to 0.96), p = 0.02). In men, smoking was negatively associated with the KIDscore (OR 0.53 (95% CI 0.33 to 0.85), p < 0.01). We conclude that inadequate periconceptional maternal vegetable intake and paternal smoking significantly reduce the implantation potential of embryos after ICSI treatment. Identifying modifiable lifestyle risk factors can contribute to directed, personalized, and individual recommendations that can potentially increase the chance of a healthy pregnancy.

Associations of post-warming embryo or blastocyst development with clinical pregnancy in vitrified embryo or blastocyst transfer cycles

Objective

To investigate whether the degree of post-warming embryo or blastocyst development is associated with clinical pregnancy in vitrified embryo or blastocyst transfer cycles.

Methods

Ninety-six vitrified cleavage-stage embryos and 58 vitrified blastocyst transfer cycles were selected. All transfer cycles were performed from February 2011 to March 2019, and all vitrified embryos or blastocysts were warmed from 4 PM to 6 PM and then transferred the next morning from 9 AM to 10 AM. The scores of the cleavage-stage embryos and blastocysts were assessed at warming and at transfer using the modified Steer method and the Gardner method, respectively. The mean embryo or blastocyst score, score of the single top-quality embryo or blastocyst, and the difference in the score between warming and transfer were compared between nonpregnant and pregnant women.

Results

In the cleavage-stage embryo transfer cycles, both the top-quality embryo score at transfer and the difference in the score between warming and transfer were significantly associated with clinical pregnancy. A top-quality embryo score at transfer of ≥60.0 (area under the curve [AUC], 0.673; 95% confidence interval [CI], 0.531–0.815) and a difference in the score between warming and transfer of ≥23.0 (AUC, 0.675; 95% CI, 0.514–0.835) were significant predictors of clinical pregnancy. In blastocyst transfer cycles, the top-quality blastocyst score at transfer was the only significant factor associated with clinical pregnancy. A top-quality blastocyst score at transfer of ≥38.3 was a significant predictor of clinical pregnancy (AUC, 0.666; 95% CI, 0.525–0.807).

Conclusion

The top-quality embryo score at transfer and the degree of post-warming embryo development were associated with clinical pregnancy in vitrified cleavage-stage embryo transfer cycles. In vitrified blastocyst transfer cycles, the top-quality blastocyst score at transfer was the only significant factor affecting clinical pregnancy.

Increased risk of maternal and neonatal complications in hormone replacement therapy cycles in frozen embryo transfer

BACKGROUND

The endometrial preparation during frozen embryo transfer (FET) can be performed by natural cycle (NC), hormone replacement therapy (HRT) cycle and cycle with ovulation induction (OI). Whether different FET preparation protocols can affect maternal and neonatal outcomes is still inconclusive.

METHODS

This was a retrospective cohort study that included 6886 women who delivered singleton live birth babies after 28 weeks of pregnancy underwent FET from January, 2015 to July, 2018. Women were divided into three groups according to the protocols used for endometrial preparation during FET: NC group (N = 4727), HRT group (N = 1642) and OI group (N = 517).

RESULTS

After adjusting for the effect of age, body mass index (BMI), irregular menstruation, antral follicle count (AFC), endometrial thickness, the levels of testosterone, anti-Müllerian hormone (AMH), preconceptional fasting glucose (PFG), systolic and diastolic pressure et al., the HRT group had higher risk of hypertensive disorders of pregnancy (HDP) compared with the NC group (adjusted odds ratio (aOR) 2.00, 95% confidence interval (CI) 1.54-2.60). Singletons born after HRT FET were at increased risk of low birth weight (LBW) compared to NC group (aOR 1.49, 95%CI 1.09-2.06). The risks of preterm birth (PTB) in the HRT and OI group were elevated compared with the NC group (aOR 1.78, 95%CI 1.39-2.28 and aOR 1.51, 95%CI 1.02-2.23, respectively).

CONCLUSIONS

The HRT protocol for endometrial preparation during frozen embryo transfer of blastocysts was associated with increased risk of maternal and neonatal complications, compared to the NC and OI protocol.

Whole-ovary decellularization generates an effective 3D bioscaffold for ovarian bioengineering

PURPOSE

To develop a new protocol for whole-ovary decellularization for the production of a 3D bioscaffold suitable for in vitro/ex vivo studies and for the reconstruction of a bioengineered ovary.

METHODS

Porcine ovaries were subjected to the decellularization process (DECELL; n = 20) that involved a freeze-thaw cycle, followed by sequential incubations in 0.5% SDS for 3 h, 1% Triton X-100 for 9 h, and 2% deoxycholate for 12 h. Untreated ovaries were used as a control (CTR; n = 6). Both groups were analyzed to evaluate cell and DNA removal as well as ECM preservation. DECELL bioscaffolds were assessed for cytotoxicity and cell homing ability.

RESULTS

DECELL ovaries maintained shape and homogeneity without any deformation, while their color turned from red to white. Histological staining and DNA quantification confirmed a decrease of 98.11% in DNA content, compared with the native tissue (CTR). Histochemical assessments demonstrated the preservation of intact ECM microarchitecture after the decellularization process. This was also confirmed by quantitative analysis of collagen, elastin, and GAG contents. DECELL bioscaffold showed no cytotoxic effects in co-culture and, when re-seeded with homologous fibroblasts, encouraged a rapid cell adhesion and migration, with repopulating cells increasing in number and aggregating in cluster-like structures, consistent with its ability to sustain cell adherence, proliferation, and differentiation.

CONCLUSION

The protocol described allows for the generation of a 3D bioscaffold that may constitute a suitable model for ex vivo culture of ovarian cells and follicles, as well as a promising tool for the reconstruction of a bioengineered ovary.

The effect of fresh IVF cycle characteristics on frozen embryo transfer (FET) outcomes

Objective

To determine the effect of fresh IVF/ICSI cycles on FET cycle embryo and pregnancy outcomes.

Methods

This retrospective cohort study included data from the medical records of 104 FET cycles performed from January 2014 to December 2016. Embryos were previously vitrified and then thawed for embryo transfer. Statistical significance was established at p<0.05. The main endpoints were FET cycle survival and pregnancy rates.

Results

A total of 104 FET cycles were analyzed for survival; 94 showed good progression and 84 achieved embryo transfers. Patients with secondary infertility achieved significantly higher pregnancy rates - 6/38 (15.8%) vs. 18/46 (39.1%) (p<0.018). Stimulation with FSH/LH resulted in more significant embryo progression, 38/48 (79.2%) vs. 28/46 (60.9%) in the FSH group (p=0.01). Patients who got pregnant from fresh cycles had the highest pregnancy rates in FET cycles (p<0.0001). Lower numbers of frozen embryos correlated with higher pregnancy rates (p=0.048). Embryos frozen on day 2 or 3 had the most significant progression (p<0.0001). Freeze-thaw intervals >12 months yielded higher pregnancy rates, 13/30 (43%), vs. 11/54 (20.4%) (p=0.025).

Conclusion

Patient pregnancy in fresh cycles is a good prognostic factor for FET cycle success. Delaying FET by more than 12 months might result in higher pregnancy rates.

Freeze-all, for whom, when, and how

Background: The 'freeze-all' practice refers to the cryopreservation of all mature oocytes or viable embryos after ovarian stimulation. The development of the vitrification technique has been crucial to make this approach a reality, since it increases the post-thaw survival rates and permits comparable implantation rates with fresh embryos. Nonetheless, as implantation probabilities are comparable to fresh embryo transfer in normo-responder patients, the freeze- all strategy has demonstrated no benefits overall.Method: Narrative review in which we give an overview of this approach, discuss recent advances in the field, as well as for whom, when and how it is recommended to emply the freeze-all technique.Results: However, there is some clinical evidence that shows its feasibility. Thus, it has been demonstrated that elevation of progesterone at the end of ovarian stimulation decreases the implantation rates after the transfer of day 6 blastocysts in fresh and some uterine pathologies; freeze-all is also the preferred option for patients undergoing pre-implantation genetic testing, since there is an improvement of the results and it allows for inclusion of all blastocysts of the cohort. In high responders, the freeze-all strategy optimizes the response whilst also minimizing the risk of ovarian hyperstimulation syndrome.Conclusion: Due to the different cases that a reproductive expert might encounter, it is essential to highlight benefits and drawbacks of this practice.

Reactive oxygen species in reproduction: harmful, essential or both?

The process of embryonic development is crucial and radically influences preimplantation embryo competence. It involves oocyte maturation, fertilization, cell division and blastulation and is characterized by different key phases that have major influences on embryo quality. Each stage of the process of preimplantation embryonic development is led by important signalling pathways that include very many regulatory molecules, such as primary and secondary messengers. Many studies, both in vivo and in vitro, have shown the importance of the contribution of reactive oxygen species (ROS) as important second messengers in embryo development. ROS may originate from embryo metabolism and/or oocyte/embryo surroundings, and their effect on embryonic development is highly variable, depending on the needs of the embryo at each stage of development and on their environment (in vivo or under in vitro culture conditions). Other studies have also shown the deleterious effects of ROS in embryo development, when cellular tissue production overwhelms antioxidant production, leading to oxidative stress. This stress is known to be the cause of many cellular alterations, such as protein, lipid, and DNA damage. Considering that the same ROS level can have a deleterious effect on the fertilizing oocyte or embryo at certain stages, and a positive effect at another stage of the development process, further studies need to be carried out to determine the rate of ROS that benefits the embryo and from what rate it starts to be harmful, this measured at each key phase of embryonic development.

Mild stimulation protocol vs conventional controlled ovarian stimulation protocol in poor ovarian response patients: a prospective randomized controlled trial

PURPOSE

To compare the efficacy of mild ovarian stimulation protocol and conventional controlled ovarian stimulation (COS) protocol for poor ovarian response (POR) patients undergoing in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI).

METHODS

This single-center prospective randomized controlled trial conducted from September 2013 to September 2015, including 191 patients who met the Bologna criteria of POR. Ninety-seven patients allocated to the mild ovarian stimulation group (MS group) were stimulated according to the letrozole/antagonist protocol, while 94 patients in the controlled ovarian stimulation group (COS group) were stimulated according to a high dose of gonadotropin (Gn) combined with gonadotropin-releasing hormone agonist (GnRH-a) stop protocol. The cumulative live birth rate was the primary outcome. Chinese clinical trial number ChiCTR-TRC-13003454.

RESULTS

Comparing with the COS group, both the stimulation duration and the total gonadotropin dose were significantly shorter and lower in the MS group (P < 0.001). A higher number of retrieved oocytes (P = 0.003) and transferrable embryos (P = 0.029) were obtained in the COS group. The cumulative live birth rates (OR 1.103; 95% CI 0.53 to 2.28; P = 0.791) were comparable between the two groups.

CONCLUSIONS

The increase of Gn dose during ovulation stimulation was associated with a higher number of transferrable embryos for POR patients, but this increase did not lead to a concomitant improvement of reproductive outcome, especially in terms of the cumulative live birth rate. Using a mild stimulation protocol was economically preferential while it was as effective as higher doses of Gn stimulation protocol in reproductive outcome for POR patients.

State of the Art in Fertility Preservation for Female Patients Prior to Oncologic Therapies

Quality of life improvement stands as one of the main goals of the medical sciences. Increasing cancer survival rates associated with better early detection and extended therapeutic options led to the specific modeling of patients’ choices, comprising aspects of reproductive life that correlated with the evolution of modern society, and requires better assessment. Of these, fertility preservation and ovarian function conservation for pre-menopause female oncologic patients pose a contemporary challenge due to procreation age advance in evolved societies and to the growing expectations regarding cancer treatment. Progress made in cell and tissue-freezing technologies brought hope and shed new light on the onco-fertility field. Additionally, crossing roads with general fertility and senescence studies proved highly beneficial due to the enlarged scope and better synergies and funding. We here strive to bring attention to this domain of care and to sensitize all medical specialties towards a more cohesive approach and to better communication among caregivers and patients.

Cumulative live birth rates of in vitro fertilization/intracytoplasmic sperm injection after multiple complete cycles in China

There were few studies of cumulative live birth rates (CLBRs) based on multicenter reproductive clinical data from the general Chinese population. Here we report a retrospective cohort study, including 14 311 women with 17 315 cycles, in three reproductive centers to evaluate two estimated parameters of CLBRs with multiple transfer cycles of in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) in a Chinese population. We found that CLBRs were related to female age and endometrial thickness. By the fourth transfer cycle, the conservative and optimal estimates of CLBRs were 52.95% and 77.30% in women under 30 years of age, and 18.17% and 26.51% in those 37 years of age or older, respectively. The two estimates were 44.70% and 63.15% in women with endometrial thickness more than 7 mm, and 32.05% and 46.18% in those with less than 7 mm, respectively. In addition, body mass index (BMI), duration of infertility, and infertility diagnoses may also be related to CLBRs on certain conditions. The findings from this study on CLBRs after multiple transfer cycles of IVF/ICSI treatment on different conditions in the Chinese population should be beneficial to both infertile couples and clinicians.

The Future of Cryopreservation in Assisted Reproductive Technologies

Societal changes and the increasing desire and opportunity to preserve fertility have increased the demand for effective assisted reproductive technologies (ART) and have increased the range of scenarios in which ART is now used. In recent years, the "freeze-all" strategy of cryopreserving all oocytes or good quality embryos produced in an IVF cycle to transfer later-at a time that is more appropriate for reasons of medical need, efficacy, or desirability-has emerged as an accepted and valuable alternative to fresh embryo transfer. Indeed, improvements in cryopreservation techniques (vitrification) and the development of more efficient ovarian stimulation protocols have facilitated a dramatic increase in the practice of elective frozen embryo transfer (eFET). Alongside these advances, debate continues about whether eFET should be a standard treatment option available to the whole IVF population or if it is important to identify patient subgroups who are most likely to benefit from such an approach. Achieving successful outcomes in ART, whether by fresh or frozen embryo transfer, is influenced by a wide range of factors. As well as the efficiency of IVF and embryo transfer protocols and techniques, factors affecting implantation include maternal aging, sperm quality, the vaginal and endometrial microbiome, and peri-implantation levels of serum progesterone. The safety of eFET, both during ART cycles and on longer-term obstetric and neonatal outcomes, is also an important consideration. In this review, we explore the benefits and risks of freeze-all strategies in different scenarios. We review available evidence on the outcomes achieved with elective cryopreservation strategies and practices and how these compare with more traditional IVF cycles with fresh embryo transfers, both in the general IVF population and in subgroups of special interest. In addition, we consider how to optimize and individualize "freeze-all" procedures to achieve successful reproductive outcomes.

Ovulation induction with high progesterone levels may be more suitable for elderly patients with low ovarian response

BACKGROUND

The objective of this study was to explore the outcomes of using the progestin-primed ovarian stimulation (PPOS) protocol in aged infertile women. The patients recruited in the study had displayed a poor ovarian response (POR) in the first IVF/ICSI-ET cycles with the ultra-short gonadotropin-releasing hormone agonist (GnRH-a) protocols.

MATERIALS AND METHODS

A self-controlled retrospective study was conducted to investigate the clinical outcomes of 117 aged infertile women who met the inclusion criteria. The patients were grouped into two; group B included patients who had displayed a poor ovarian response (POR) in the first IVF/ICSI-ET cycle with the ultra-short GnRH-a protocol. Group A was made up of patients who underwent the PPOS protocol in the second cycle. The study was done between January 2015 to May 2018 in the reproductive and genetic centre of integrated traditional and western medicine, Affiliated hospital of Shandong University of traditional Chinese medicine. Reproduction-related clinical outcomes in the two groups were compared.

RESULTS

There were no statistically significant differences in the serum levels of LH, E_2, and P on the trigger day between group A and group B (P＞0.05). The number of follicles with a diameter > 14 mm was significantly higher in the PPOS protocol patients than in the ultra-short GnRH-a protocol group (4.83 ± 2.82 vs. 3.25 ± 2.53, P < 0.01). The duration and total dosage of gonadotropin of the PPOS protocol group were less than in the previous ultra-short GnRH-a protocol, although the statistical differences were not significant (P > 0.05). The number of eggs obtained in the PPOS group was significantly higher than that of the previous one (4.29 ± 3.11 vs. 2.76 ± 2.33, P < 0.05). The numbers of MII eggs, cleavage, 2 P N, transplantable embryos, and high quality embryos were higher in the PPOS protocol group than that in the ultra-short protocol group. However, the differences between the two groups in all the above parameters were not statistically significant (P > 0.05). The rate of high-quality embryos was significantly higher in the PPOS protocol group than in the ultra-short protocol group (38.61(100/259) vs. 32.02(65/203), P < 0.05). Although not statistically significant (P > 0.05), the abortion rate of the PPOS protocol group was higher than that of the ultra-short protocol group. The clinical pregnancy and live birth rates were significantly higher in the PPOS protocol group than in the ultra-short protocol group (p < 0.05). The clinical pregnancy rates in the PPOS protocol group and the ultra-short protocol group were 32.35 % and 25.53 % respectively while the live birth rates were 27.45 % and 21.28 % respectively.

CONCLUSION

Compared with the ultra-short protocol, the PPOS protocol improves the number of follicles, the number of eggs, clinical pregnancy, and live birth rates in POR patients. The PPOS protocol could, therefore, provide a novel treatment strategy for inducing ovulation in POR patients.

A monocentric analysis of the efficacy of extracellular cryoprotectants in unfrozen solutions for cleavage stage embryos

BACKGROUND

In the absence of international guidelines indicating the usage of vitrification rather than slow-freezing, the study aim was to analyze a large cohort of slow-frozen/thawed embryos to produce a rationale supporting the standardization of IVF cryopreservation policy.

METHODS

This retrospective analysis included 4779 cleavage stage embryos cryopreserved by slow-freezing/thawing from September 2009 to April 2017 at a single Center. Biological and clinical outcomes of three different commercial kits adopted sequentially, i.e. Vitrolife Cleave Kit® from Vitrolife (kit 1) vs. K-SICS-5000 Kit® and K-SITS-5000 Kit® from Cook Medical (kit 2) and Freeze/Thaw 1™ Kit® from Vitrolife (kit 3) were collected and compared in the light of cryoprotectants composition.

RESULTS

Kit 3 compared to kit 1 and kit 2 showed significantly (P < 0.001) higher embryo survival (79.9% vs. 75.6 and 68.1%, respectively) and frozen embryo replacement (91.5% vs. 86.5 and 83.3%, respectively) rates, and significantly (P < 0.001) lower blastomere degeneration rate (41.5% vs. 43.6 and 52.4%, respectively). No significant difference for clinical outcomes was observed among kits. Only a slight positive trend was observed for kit 3 vs. kit 1 and kit 2 on delivery rate per thawing cycle (7.12% vs. 4.19 and 4.51%, respectively; P < 0.058) and live birth rate (3.07% vs. 2.59 and 1.93%, respectively, P < 0.069). Thawing solutions of kit 3 were similar to those of any warming protocol.

CONCLUSIONS

A defined concentration of extracellular cryoprotectants in thawing/warming solutions had a beneficial effect on the embryo cryosurvival rate. Results could provide the rationale for the adoption of a single standardized warming protocol.

Different Origin, Different Response: Gene Expression Pattern in Collapsed Vitrified Blastocyst

There is a large body of animal experimental data about assisted reproductive techniques that could be applied to improve clinical outcomes. The great part of this information was obtained from research on in vivo-derived embryos. But whether these results are always similar with those we expect from embryos having in vitro origin in the clinical cases is a critical question. The present study was designed to compare the effects of vitrification (VIT) and artificial collapse (AC) as two commonly used techniques on in vivo- and in vitro-derived mouse embryos. In this regard, both origins of blastocysts were produced and randomly divided into three experimental groups, including control (non-vitrified), VIT, and AC-VIT. The survival and hatching rates and the expression of development-related genes were assessed in all groups and compared with their control counterpart. According to our results, although in vivo and in vitro origins followed the same pattern in the hatching rate, the real-time PCR data showed two distinct patterns of gene expression. Compared to the control, vitrification increased the expression of pluripotency genes in in vivo group. While in vitro vitrified blastocysts showed a significant reduction in the transcripts of these genes. More interestingly, although AC resulted in a sharp decrease of Gata6 and Grb2 in post warmed in vivo blastocysts, it could not affect the vitrified IVP ones. In conclusion, it seems that vitrification and artificial collapse techniques have different effects on embryo fate depending on in vivo or in vitro origins of the embryos.

IVF-on-a-Chip: Recent Advances in Microfluidics Technology for In Vitro Fertilization

In vitro fertilization (IVF) has been one of the most exciting modern medical technologies. It has transformed the landscape of human infertility treatment. However, current IVF procedures still provide limited accessibility and affordability to most infertile couples because of the multiple cumbersome processes and heavy dependence on technically skilled personnel. Microfluidics technology offers unique opportunities to automate IVF procedures, reduce stress imposed upon gametes and embryos, and minimize the operator-to-operator variability. This article describes the rapidly evolving state of the application of microfluidics technology in the field of IVF, summarizes the diverse angles of how microfluidics has been complementing or transforming current IVF protocols, and discusses the challenges that motivate continued innovation in this field.

Predicting the cumulative chance of live birth over multiple complete cycles of in vitro fertilization: an external validation study

STUDY QUESTION

Are the published pre-treatment and post-treatment McLernon models, predicting cumulative live birth rates (LBR) over multiple complete IVF cycles, valid in a different context?

SUMMARY ANSWER

With minor recalibration of the pre-treatment model, both McLernon models accurately predict cumulative LBR in a different geographical context and a more recent time period.

WHAT IS KNOWN ALREADY

Previous IVF prediction models have estimated the chance of a live birth after a single fresh embryo transfer, thereby excluding the important contribution of embryo cryopreservation and subsequent IVF cycles to cumulative LBR. In contrast, the recently developed McLernon models predict the cumulative chance of a live birth over multiple complete IVF cycles at two certain time points: (i) before initiating treatment using baseline characteristics (pre-treatment model) and (ii) after the first IVF cycle adding treatment related information to update predictions (post-treatment model). Before implementation of these models in clinical practice, their predictive performance needs to be validated in an independent cohort.

STUDY DESIGN, SIZE, DURATION

External validation study in an independent prospective cohort of 1515 Dutch women who participated in the OPTIMIST study (NTR2657) and underwent their first IVF treatment between 2011 and 2014. Participants underwent a total of 2881 complete treatment cycles, with a complete cycle defined as all fresh and frozen thawed embryo transfers resulting from one episode of ovarian stimulation. The follow up duration was 18 months after inclusion, and the primary outcome was ongoing pregnancy leading to live birth.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Model performance was externally validated up to three complete treatment cycles, using the linear predictor as described by McLernon et al. to calculate the probability of a live birth. Discrimination was expressed by the c-statistic and calibration was depicted graphically in a calibration plot. In contrast to the original model development cohort, anti-Müllerian hormone (AMH), antral follicle count (AFC) and body weight were available in the OPTIMIST cohort, and evaluated as potential additional predictors for model improvement.

MAIN RESULTS AND THE ROLE OF CHANCE

Applying the McLernon models to the OPTIMIST cohort, the c-statistic of the pre-treatment model was 0.62 (95% CI: 0.59-0.64) and of the post-treatment model 0.71 (95% CI: 0.69-0.74). The calibration plot of the pre-treatment model indicated a slight overestimation of the cumulative LBR. To improve calibration, the pre-treatment model was recalibrated by subtracting 0.35 from the intercept. The post-treatment model calibration plot revealed accurate cumulative LBR predictions. After addition of AMH, AFC and body weight to the McLernon models, the c-statistic of the updated pre-treatment model improved slightly to 0.66 (95% CI: 0.64-0.68), and of the updated post-treatment model remained at the previous level of 0.71 (95% CI: 0.69-0.73). Using the recalibrated pre-treatment model, a woman aged 30 years with 2 years of primary infertility who starts ICSI treatment for male factor infertility has a chance of 40% of a live birth from the first complete cycle, increasing to 72% over three complete cycles. If this woman weighs 70 kg, has an AMH of 1.5 ng/mL and an AFC of 10 measured at the beginning of her treatment, the updated pre-treatment model revises the estimated chance of a live birth to 30% in the first complete cycle and 59% over three complete cycles. If this woman then has five retrieved oocytes, no embryos cryopreserved and a single fresh cleavage stage embryo transfer in her first ICSI cycle, the post-treatment model estimates the chances of a live birth at 28 and 58%, respectively.

LIMITATIONS, REASONS FOR CAUTION

Two randomized controlled trials (RCT) evaluating the effectiveness of gonadotropin dose individualization on basis of the AFC were nested within the OPTIMIST study. The strict dosing regimens, the RCT in- and exclusion criteria and the limited follow up time of 18 months might have influenced model performance in this independent cohort. Also, consistent with the original model development study, external validation was performed using the optimistic assumption that the cumulative LBR in couples who discontinue treatment without a live birth would have been equal to that of those who continue treatment.

WIDER IMPLICATIONS OF THE FINDINGS

After national recalibration to account for geographical differences in IVF treatment, the McLernon prediction models can be introduced as new counselling tools in clinical practice to inform patients and to complement clinical reasoning. These models are the first to offer an objective and personalized estimate of the cumulative probability of a live birth over multiple complete IVF cycles.

STUDY FUNDING/COMPETING INTEREST(S)

No external funds were obtained for this study. M.J.C.E., D.J.M. and S.B. have nothing to disclose. J.A.L, S.C.O, T.C.v.T. and H.LT. received an unrestricted personal grant from Merck BV. B.W.M. is supported by a NHMRC Practitioner Fellowship (GNT1082548) and reports consultancy for ObsEva, Merck and Guerbet. F.J.M.B. receives monetary compensation as a member of the external advisory board for Merck BV (the Netherlands) and Ferring pharmaceutics BV (the Netherlands), for consultancy work for Gedeon Richter (Belgium) and Roche Diagnostics on automated AMH assay development, and for a research cooperation with Ansh Labs (USA).

TRIAL REGISTRATION NUMBER

Not applicable.

Does Overnight Culture of Cleaved Embryos Improve Pregnancy Rate in Vitrified-Warmed Embryo Transfer Programme?

Background

Vitrification is a routine procedure in assisted reproductive technique (ART) lab. However, there is widespread variability between protocols of different centres. The aim of this study was to compare the chemical pregnancy, clinical pregnancy and live birth rates between one-day embryo culture and immediate transfer for frozen-thawed embryo transfer (FET) cycles.

Methods

In this cohort retrospective study, 366 FET cycles were divided into two groups: Group A, the embryos were warmed one day before transfer, and were cultured overnight; Group B, the embryos were warmed on the same day of transfer, at least were cultured 1 h before embryo transfer (ET). Chemical and clinical pregnancy and live birth rates were compared between two groups.

Results

The chemical pregnancy was higher in group A than B (37.9% versus 28.9%), but this difference was not significant (P = 0.07). Clinical pregnancy (30.8% versus 24.1%) and live birth (19.8% versus 22.05%) were similar in group A and B, (P = 0.15), and (P = 0.8). Conclusion: In conclusion, overnight culture and confirmation of mitosis resumption was not essential for FET cycles in vitrification method.

Serum estradiol level on trigger day impacts clinical pregnancy rate in modified natural frozen embryo transfer cycles

OBJECTIVE

To examine the predictive value of serum estradiol and progesterone on the day of human chorionic gonadotropin (hCG) administration and embryo transfer for clinical pregnancy rate in modified natural-cycle frozen embryo transfer (NC-FET).

METHODS

In a longitudinal prospective study, all eligible women who underwent NC-FET cycles with hCG triggering in Royan Institute, Tehran, Iran, from June 1, 2015, to December 31, 2016, were evaluated. Serum estradiol and progesterone levels were measured at menstrual cycle initiation, on day of trigger with hCG, on day of embryo transfer, and in pregnant women every 7 days until the observation of a gestational sac with embryonic heartbeat.

RESULTS

In total, 101 modified natural FET cycles were assessed, and the clinical pregnancy and live birth rates achieved were 34 (33.6%) and 32 (31.6%), respectively. The changes in estradiol level during early pregnancy showed an increase by an average of 200 pg/mL per week. Multivariable logistic regression analysis showed that only the estradiol level on the hCG day was a significant predictive variable for clinical pregnancy following NC-FET (P=0.04).

CONCLUSION

Estradiol level on the day of hCG trigger predicted the clinical pregnancy rates after modified NC-FET; this likely mirrored the developmental competence of the corpus luteum and an appropriate luteal structure-function.