Obese outbred mice only partially benefit from diet normalization or calorie restriction as preconception care interventions to improve metabolic health and oocyte quality

STUDY QUESTION

Can diet normalization or a calorie-restricted diet for 2 or 4 weeks be used as a preconception care intervention (PCCI) in Western-type diet-induced obese Swiss mice to restore metabolic health and oocyte quality?

SUMMARY ANSWER

Metabolic health and oocyte developmental competence was already significantly improved in the calorie-restricted group after 2 weeks, while obese mice that underwent diet normalization showed improved metabolic health after 2 weeks and improved oocyte quality after 4 weeks.

WHAT IS KNOWN ALREADY

Maternal obesity is linked with reduced metabolic health and oocyte quality; therefore, infertile obese women are advised to lose weight before conception to increase pregnancy chances. However, as there are no univocal guidelines and the specific impact on oocyte quality is not known, strategically designed studies are needed to provide fundamental insights in the importance of the type and duration of the dietary weight loss strategy for preconception metabolic health and oocyte quality.

STUDY DESIGN, SIZE, DURATION

Outbred female Swiss mice were fed a control (CTRL) or high-fat/high-sugar (HF/HS) diet. After 7 weeks, some of the HF mice were put on two different PCCIs, resulting in four treatment groups: (i) only control diet for up to 11 weeks (CTRL_CTRL), (ii) only HF diet for up to 11 weeks (HF_HF), (iii) switch at 7 weeks from an HF to an ad libitum control diet (HF_CTRL) and (iv) switch at 7 weeks from an HF to a 30% calorie-restricted control diet (HF_CR) for 2 or 4 weeks. Metabolic health and oocyte quality were assessed at 2 and 4 weeks after the start of the intervention (n = 8 mice/treatment/time point).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Changes in body weight were recorded. To study the impact on metabolic health, serum insulin, glucose, triglycerides, total cholesterol and alanine aminotransferase concentrations were measured, and glucose tolerance and insulin sensitivity were analyzed at PCCI Weeks 2 and 4. The quality of in vivo matured oocytes was evaluated by assessing intracellular lipid droplet content, mitochondrial activity and localization of active mitochondria, mitochondrial ultrastructure, cumulus cell targeted gene expression and oocyte in vitro developmental competence.

MAIN RESULTS AND THE ROLE OF CHANCE

Significant negative effects of an HF/HS diet on metabolic health and oocyte quality were confirmed (P < 0.05). HF_CTRL mice already showed restored body weight, serum lipid profile and glucose tolerance, similar to the CTRL_CTRL group after only 2 weeks of PCCI (P < 0.05 compared with HF_HF) while insulin sensitivity was not improved. Oocyte lipid droplet volume was reduced at PCCI Week 2 (P < 0.05 compared with HF_HF), while mitochondrial localization and activity were still aberrant. At PCCI Week 4, oocytes from HF_CTRL mice displayed significantly fewer mitochondrial ultrastructural abnormalities and improved mitochondrial activity (P < 0.05), while lipid content was again elevated. The in vitro developmental capacity of the oocytes was improved but did not reach the levels of the CTRL_CTRL mice. HF_CR mice completely restored cholesterol concentrations and insulin sensitivity already after 2 weeks. Other metabolic health parameters were only restored after 4 weeks of intervention with clear signs of fasting hypoglycemia. Although all mitochondrial parameters in HF_CR oocytes stayed aberrant, oocyte developmental competence in vitro was completely restored already after 2 weeks of intervention.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

In this study, we applied a relevant HF/HS Western-type diet to induce obesity in an outbred mouse model. Nevertheless, physiological differences should be considered when translating these results to the human setting. However, the in-depth study and follow-up of the metabolic health changes together with the strategic implementation of specific PCCI intervals (2 and 4 weeks) related to the duration of the mouse folliculogenesis (3 weeks), should aid in the extrapolation of our findings to the human setting.

WIDER IMPLICATIONS OF THE FINDINGS

Our study results with a specific focus on oocyte quality provide important fundamental insights to be considered when developing preconception care guidelines for obese metabolically compromised women wishing to become pregnant.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by the Flemish Research Fund (FWO-SB grant 1S25020N and FWO project G038619N). The authors declare there are no conflicts of interest.

O-136 Myeloperoxidase Kit as valuable alternative for LeucoScreen to differentiate round cells in semen samples

Study question

Is Myeloperoxidase Kit, validated for blood but not for semen, a valuable alternative for Leucoscreen to differentiate round cells in semen?

Summary answer

Myeloperoxidase Kit is a non-toxic alternative for LeucoScreen to differentiate round cells in semen, with the advantage of assessing a 1:2 dilution of semen.

What is known already

As stated in the WHO laboratory manual, the routine assay of peroxidase activity is useful as screening technique for quantifying the leucocyte population in semen samples. The clinically relevant neutrophil leucocytes stain peroxidase positive and can hereby be differentiated from spermatids and spermatocytes. The commercially available kit, Leucoscreen (Fertipro, Beernem, Belgium) uses carcinogenic ortho-toluidine and was therefore withdrawn from the market and an alternative, LeucoScreen Plus, was suggested. A disadvantage of LeucoScreen Plus is the necessity to dilute the sample 1:6. Testing an alternative inexpensive, quick and not carcinogenic method to differentiate round cells without excessive dilutions, is worth investigating.

Study design, size, duration

Intra- and inter-variability of Myeloperoxidase Kit (Ral Diagnostics, MLS NV, Menen, Belgium) was assessed by evaluating 2 semen samples 10 times by one technician, and 10 semen samples by 2 technicians, respectively. The stability of the working solution for 5 days was tested on 10 semen samples. The accuracy was tested on 80 samples by comparing Myeloperoxidase Kit with LeucoScreen. The study was performed from July till November 2020.

Participants/materials, setting, methods

Working solution was made from the Myeloperoxidase Kit (3/5 bottles): 1 ml alphanaphtol solution, 4 ml pyronine solution and 1 droplet hydrogen peroxide. Semen samples brought to the Andrology Lab for diagnostic evaluation and presenting with round cells were included. To differentiate peroxidase positive leucocytes (dark pink with dark granules) from other round cells (unstained or pink), 10 µl solution was mixed with 10 µl of semen and assessed with phase contrast at 400x.

Main results and the role of chance

The intra-variability of round cell differentiation was acceptable with %CV 6.6% for sample 1 (mean ± SD: 30.8% ± 2.04%) and 4.1% for sample 2 (mean ± SD: 56.7% ± 2.31%), both lower than the 10% criterium. The inter-variability was acceptable according to Passing&Bablok (95%CI Intercept A: -1.25 to 0.36; 95%CI Slope B: 0.92 to 1.11) and Spearman rank correlation coefficient (r = 0.983 with P &lt; 0.001). The stability of the working solution after 5 days, kept at room temperature during the day and at 4 °C at night, compared with freshly made working solution was adequate according to Passing&Bablok (95%CI Intercept A: -2.33 to 0.47; 95%CI Slope B: 0.85 to 1.17) and Spearman rank correlation coefficient (r = 0.991 with P &lt; 0.0001). Also the accuracy could be accepted as the Bland-Altman plot shows a substantial agreement between Leucoscreen and Myeloperoxidase Kit (difference 0.6%) without a proportional bias.

Limitations, reasons for caution

Granules in neutrophils stain differently with Myeloperoxidase Kit, with Leucoscreen and with Leucoscreen Plus, which requires a short adaptation when starting with a new kit.

Wider implications of the findings

The use of Myeloperoxidase Kit to differentiate round cells in semen is cheap, non-toxic and easy. It is a valuable asset in the andrology lab because semen samples with low round cell concentrations can be counted in a 1:2 dilution and the working solution can be kept for 5 days.

Trial registration number

None

O-016 Variability of sperm DNA fragmentation in a longitudinal trial of intrauterine inseminations

Study question

Does variability in sperm DNA fragmentation (SDF) follow that observed in standard semen parameters and is this linked to outcome results?

Summary answer

Variability in SDF and in semen parameters is comparable but live birth rate tends to be lower in men with repetitive high SDF.

What is known already

Environmental, technical and biological factors are implicated in the intra-individual variability observed in routine semen parameters. This variation is not observed in SDF testing using the sperm chromatin structure assay. Most laboratories undertake SDF testing on one semen sample, assuming that one single measurement represents the patient’s condition and is both stable and associated with a good diagnostic value. Most variability observed in SDF tests relies essentially on paired observations with a short or long time interval between test and retest.

Study design, size, duration

A monocentric, prospective cohort study was conducted October 2017 - October 2020. Couples with a mild or unexplained male infertility initiated a natural cycle IUI protocol until pregnancy was achieved for a maximum of four cycles. 313 semen samples from 112 men were analyzed for SDF before and after semen preparation. This work was supported by the Fonds Wetenschappelijk Onderzoek (FWO), Research Foundation Flanders (grant number T007016N).

Participants/materials, setting, methods

Semen samples were analyzed and prepared by density gradient centrifugation. SDF was assessed via TUNEL assay before and after preparation. Clinical pregnancies and live births were registered. Intraclass Correlation Coefficients (ICC) were used to estimate the intra- and inter-variability.

Main results and the role of chance

The ICC for SDF (0.33 in the ejaculate, 0.54 after density gradient) and semen variables (0.42-0.62) were comparable. These values mean considerable intra-individual variation, both for semen variables and for SDF variables.

Using fertile threshold SDF values (13% before and 8% after density gradient), 3 patient groups were distinguished: 13.4% of men showed high SDF in all ejaculates, 58.0% always showed low SDF and 28.6% fluctuated between the two during the trial. After density gradient more patients were found in the High group (42.3%) and less patients in the Low group (26.1%), while the proportion of Fluctuaters remained constant (31.5%). Most (66.7%) men with high SDF retain their high SDF after gradient, and also 56.3% of the Fluctuaters react with a high SDF after gradient. The Low SDF category, on the contrary, distributes itself evenly between the three categories after gradient.

In the 112 couples, 26 (23.2%) clinical pregnancies were obtained with 21 (18.8%) live births. The live birth rate for the High, Fluctuaters and Low groups was 6.7%, 18.8% and 20.0% for ejaculate SDF and 12.8%, 20.0% and 27.6% for SDF after density gradient. These differences however did not reach significance (chi-square testing, p &gt; 0.05).

Limitations, reasons for caution

Our results need to be substantiated and opportunities created to explore populations with an extreme male factor and the clinical implications in different assisted reproductive techniques.

Wider implications of the findings

SDF testing provides additional information and helps identify causes otherwise missed with traditional semen analysis alone. One out of 3 patients fluctuate in their SDF values. A second SDF testing is advocated to isolate these fluctuaters. The detection of DNA damage after semen preparation is indispensable for therapeutic purposes.

Trial registration number

NCT03319654

P-668 The LH endocrine profile in Gonadotropin-Releasing Hormone analogue cycles

Study question

What does the evolution of luteinizing hormone (LH) throughout the follicular phase look like in different treatment protocols for ovarian stimulation in IVF/ICSI?

Summary answer

Evolution of LH during the follicular phase of ovarian stimulation differs between Gonadotropin-Releasing Hormone (GnRH) analogues, with a significant decrease of LH in antagonist cycles.

What is known already

Physicians aim to tailor ovarian stimulation protocols to the patient, with protocols varying in type of GnRH analogue and gonadotropin. However, there is no clear consensus on the best treatment protocol and especially the role of LH is still not completely understood as earlier studies focused mainly on suppressing LH levels. Literature has since indicated that excessively suppressed LH levels could be detrimental for clinical outcomes. Research on LH is hampered by multiple measurements during the cycle, different treatment schedules and patients switching schedules over time.

Study design, size, duration

This was a non-interventional, retrospective, observational cohort study. 2200 ovarian stimulation cycles for assisted reproduction were analyzed, in 1303 individual patients. Patients were treated during the period of January 1st 2015 until September 30th 2020. Cycles were included if the patient was between 18 and 43 years of age, stimulated with human menopausal gonadotropin (hMG) or recombinant follicle stimulating hormone (rec-FSH, follitropin α or β) and using GnRH analogues.

Participants/materials, setting, methods

Data were extracted from two databases used at a tertiary infertility clinic. Cycles were divided into six treatment protocols: GnRH antagonist/hMG (13.8%), antagonist/rec-FSH (19.7%), long agonist/hMG (35.7%), long agonist/rec-FSH (4.8%), short agonist/hMG (22.5%) and short agonist/rec-FSH (3.5%). 59.5% of cycles were pretreated with an oral contraceptive pill (OCP). LH evolution was visualized by plotting LH levels against the days of the follicular phase and repeated daily LH measures were fitted with a linear mixed model.

Main results and the role of chance

Basal LH was significantly lower in antagonist/hMG cycles pretreated with OCP compared to no pretreatment (estimated difference -1.23 IU/L, p &lt; 0.001). Mean LH value throughout the follicular phase was significantly lower with OCP pretreatment in antagonist/hMG (estimated difference -1.05 IU/L, p &lt; 0.001) and antagonist/rec-FSH cycles (estimated difference -0.52 IU/L, p &lt; 0.001). When LH evolution throughout the follicular phase was analyzed, no significantly different evolution between cycles with and without OCP was detected (all p &gt; 0.1). Hence further analysis of the LH profiles was performed in the six protocol groups making no distinction between OCP use or not. LH evolution was significantly different between all six protocol groups (p &lt; 0.001). In antagonist/hMG cycles, LH values showed a significant decrease of 0.17 IU/L per day (p &lt; 0.001). In antagonist/rec-FSH cycles, the decrease per day was 0.26 IU/L (p &lt; 0.001).The decrease in LH was significantly larger in rec-FSH cycles than hMG (estimated difference 0.09 IU/L per day, p &lt; 0.001). Short agonist/hMG cycles showed a significant increase in LH of 0.04 IU/L per day (p = 0.002), while the increase of 0.01 IU/L per day in rec-FSH cycles was not significant (p = 1.00). In long agonist cycles, no significant in- or decrease in LH values during the follicular phase was found (p = 1.00).

Limitations, reasons for caution

Stimulation protocols were chosen by the treating physician which is a limitation of the retrospective design. The authors were able to partly respond to this limitation by adjusting for age and using different cycles per patient in all mixed models.

Wider implications of the findings

Using profiles to show LH evolution allowed the visualization of the decrease in the evolution of LH in antagonist cycles, even more pronounced in cycles stimulated with rec-FSH compared to hMG. This decrease in LH and the potential impact on estradiol levels and follicle growth needs further examination.

Trial registration number

not applicable

Peak retrograde flow a potential objective management tool to identify young adults with varicocele 'at risk' for a high sperm DNA fragmentation

INTRODUCTION

Determining which patients are negatively affected by varicocele would enable clinicians to better select those men who would benefit most from surgery. Since conventional semen parameters, have been limited in their ability to evaluate the negative effects of varicocele on fertility, specialized laboratory tests have emerged.

OBJECTIVE

To identify clinical and ultrasound parameters (including PRF) which would negatively influence standard and functional semen variables in young adults with a varicocele.

DESIGN

Prospective, cross-sectional observational study.

SETTING

Antwerp University Hospital, Belgium.

PATIENT(S)

Young volunteers between 16 and 26 years, Tanner 5, were recruited.

INTERVENTION(S)

Every participant had a scrotal ultrasound to calculate testicular volumes. If a varicocele was present, the grade, vein diameter, peak retrograde flow (PRF) in supine position and spontaneous reflux in standing position were measured. All participants provided a semen sample. Standard semen parameters were analyzed and sperm DNA fragmentation.

MAIN OUTCOME MEASURE(S)

Of all clinical and ultrasound parameters tested, PRF was an objective tool identifying young adults with a varicocele. PRF was highlighted by the prevalence of SDF, both in the total and vital fractions of the spermatozoa, providing opportunities to manage such 'at-risk' adolescents/young adults.

RESULT(S)

Total SDF was significantly increased in grade 3 varicocele compared to grade 1 and 2 but no significant difference with vital SDF or standard descriptive semen parameters was seen. Total and vital SDF on the other hand were significantly increased when PRF was above 38.4 cm/s. Standard semen analysis showed no difference with PRF as an independent predictor. Testicular atrophy index, varicocele vein diameter and spontaneous reflux revealed no significant differences in both the descriptive and functional semen variables.

DISCUSSION

Descriptive semen parameters showed no significant difference between the non-varicocele controls and the varicocele group with low and high PRF. Increased PRF negatively influenced sperm quality via increased DNA fragmentation both in the total as in the vital fractions of the semen.

CONCLUSION(S)

Of all clinical and ultrasound parameters tested, PRF was an objective non-invasive tool to identify varicocele patients at risk for a high SDF.

Systematic development of a mobile preconception lifestyle programme for couples undergoing IVF: the PreLiFe-programme

STUDY QUESTION

Can we develop a preconception lifestyle programme for couples undergoing IVF that is in line with their needs.

SUMMARY ANSWER

A mobile preconception lifestyle programme was systematically developed based on expert opinion, literature and needs of IVF-patients.

WHAT IS KNOWN ALREADY

A healthy lifestyle prior to conception is not only beneficial for the general health of couples, but evidence on its importance for their reproductive health and the health of their children is also emerging. So far, the vast majority of fertility clinics do not offer a lifestyle programme for couples undergoing IVF. Therefore, the present study aimed to develop a lifestyle programme for IVF-couples.

STUDY DESIGN, SIZE, DURATION

The development of the PreLiFe-programme was guided by the steps of the Medical Research Council (MRC) framework for developing complex interventions, a systematic approach for developing theory- and evidence-based health promotion interventions.

PARTICIPANTS/MATERIALS, SETTINGS, METHODS

First, the evidence base on lifestyle programmes for IVF-couples was reviewed. Second, several iterations between an expert panel, the literature, and quantitative and qualitative data from IVF-patients identified the content, the format, behaviour change techniques and theory of the programme. Third, the PreLiFe-programme was produced and the expected process and outcomes of a randomized controlled trial assessing it were modelled. Finally, user tests among experts and patients and pilot tests among patients were conducted.

MAIN RESULTS AND ROLE OF CHANCE

The finally developed PreLiFe-programme is a mobile application to be used autonomously by both partners of IVF-couples during the first year of IVF, in combination with motivational interviewing over the telephone every three months (i.e. blended care). The PreLiFe-programme provides advice and skills training on physical activity, diet and mindfulness based stress reduction and is in part tailored based on monitoring and tracking the lifestyle of patients. Based on the literature the expert panel considers it plausible that all three components contribute to IVF-success rates. The PreLiFe-programme is likely to be acceptable to patients as it meets the need of patients for lifestyle advice and treatment information.

LIMITATIONS, REASON FOR CAUTION

The pilot in IVF-couples had a 3-month duration. The feasibility of the PreLiFe-programme in other infertile populations and/or upon longer use is yet to be examined. Whether the PreLiFe-programme effectively improves lifestyle and IVF-success rates is currently being examined in a trial randomizing heterosexual couples starting IVF to the PreLiFe-programme or an attention-control group for 12 months.

WIDER IMPLICATIONS OF THE FINDINGS

If the PreLiFe-programme improves lifestyle and the chance of IVF-success, it will be a powerful tool and provide guidance for implementing lifestyle programmes in fertility clinics.

STUDY FUNDING/COMPETING INTEREST(S)

Funded by the Research Foundation Flanders (FWO-TBM (Applied Biomedical Research with a Primary Social finality); reference: T005417N). The authors have no conflict of interest to report.

TRIAL REGISTRATION NUMBER

NCT03790449.

P–513 Analysis of the extent of dropout-rates by extraction from cumulative live birth rates in IVF/ICSI: systematic review and meta-analysis

Study question

The purpose of this systematic review is to calculate dropout-rates of IVF/ICSI treatment by analysing the published cumulative live birth rates of IVF/ICSI treatment.

Summary answer

One out of three patients stop their treatment after their first IVF/ICSI cycle and dropout-rates tend to increase per consecutive cycle.

What is known already

Cumulative live birth rates (CLBRs) have created the possibility to present realistic probabilities of having a live birth after IVF/ICSI treatment. However, it is noted that a significant percentage of the patients stop their treatment before having a child (“dropout”). Possible reasons and predicting factors for dropout of treatment are already extensively investigated. However, only a few studies try to report about the incidence of dropout. Publications on CLBRs of large numbers of patients allow the extraction of dropout-rates. These rates will provide insight in the extent of the problem and could be used as a reference for interventional studies.

Study design, size, duration

Four databases (PubMed, The Cochrane Library, EMBASE, DoKS) were systematically searched from 1992 to December 2020. Search terms referred to “cumulative live birth” AND “ART/IVF/ICSI”. No restrictions were made on the type or language of publication. Studies were included if they reported absolute numbers of patients and live births per consecutive complete IVF/ICSI cycle or per consecutive embryo transfer cycle, starting from the first IVF/ICSI cycle for each patient.

Participants/materials, setting, methods

Dropout-rates per cycle were calculated in two manners: “intrinsic dropout-rate” with all patients that started the particular IVF/ICSI cycle in the denominator, and “potential dropout-rate” with all patients who did not achieve a live birth after IVF/ICSI (and potentially could have started a consecutive cycle) in the denominator. Dropout-rates were analysed for consecutive complete cycles and consecutive embryo transfer cycles, because these two manners are used in reporting CLBRs, often related to the reimbursement policy.

Main results and the role of chance

This review included 29 studies and almost 800,000 patients from different countries and registries.

Regarding the patients who started their first IVF/ICSI cycle, trying to conceive their first child by IVF/ICSI, intrinsic dropout-rate was 33% (weighted average) after the first complete cycle, meaning they did not return for their second oocyte retrieval cycle. After the first embryo transfer cycle, intrinsic dropout-rate was 27% (weighted average), meaning those patients did not return for their next frozen-thawed embryo transfer cycle or for the next oocyte retrieval cycle. Regarding the patients who did not achieve a live birth after the first complete cycle, potential dropout-rate was 48% (weighted average), and 37% (weighted average) after the first embryo transfer cycle.

Both potential and intrinsic dropout-rates for both consecutive complete and embryo transfer cycles tended to increase with cycle number.

One study on second IVF/ICSI conceived children showed a potential dropout-rate after the first complete cycle of 29%. From studies on women &gt;40 years of age, the potential dropout-rate after the first complete cycle was 45% (weighted average) and from studies with the uses of testicular sperm extraction, the potential dropout-rate after the first complete cycle was 34% (weighted average).

Limitations, reasons for caution

Our analysis was hampered by the different ways of reporting on CLBRs (complete cycles versus embryo transfer cycles), informative censoring, patients changing clinics and spontaneous pregnancies. Dropout-rates were potentially overestimated given that spontaneous pregnancies were not taken into account.

Wider implications of the findings: The extent of dropout in IVF/ICSI treatment is substantial and has an important impact on its effectiveness. Therefore, it is a challenge for fertility centers to try to keep patients longer on board, by taking into account the patients’ preferences and managing their expectations.

Trial registration number

PROSPERO Registration number: CRD42020223512

P-513 Analysis of the extent of dropout-rates by extraction from cumulative live birth rates in IVF/ICSI: systematic review and meta-analysis

Study question

The purpose of this systematic review is to calculate dropout-rates of IVF/ICSI treatment by analysing the published cumulative live birth rates of IVF/ICSI treatment.

Summary answer

One out of three patients stop their treatment after their first IVF/ICSI cycle and dropout-rates tend to increase per consecutive cycle.

What is known already

Cumulative live birth rates (CLBRs) have created the possibility to present realistic probabilities of having a live birth after IVF/ICSI treatment. However, it is noted that a significant percentage of the patients stop their treatment before having a child (“dropout”). Possible reasons and predicting factors for dropout of treatment are already extensively investigated. However, only a few studies try to report about the incidence of dropout. Publications on CLBRs of large numbers of patients allow the extraction of dropout-rates. These rates will provide insight in the extent of the problem and could be used as a reference for interventional studies.

Study design, size, duration

Four databases (PubMed, The Cochrane Library, EMBASE, DoKS) were systematically searched from 1992 to December 2020. Search terms referred to “cumulative live birth” AND “ART/IVF/ICSI”. No restrictions were made on the type or language of publication. Studies were included if they reported absolute numbers of patients and live births per consecutive complete IVF/ICSI cycle or per consecutive embryo transfer cycle, starting from the first IVF/ICSI cycle for each patient.

Participants/materials, setting, methods

Dropout-rates per cycle were calculated in two manners: “intrinsic dropout-rate” with all patients that started the particular IVF/ICSI cycle in the denominator, and “potential dropout-rate” with all patients who did not achieve a live birth after IVF/ICSI (and potentially could have started a consecutive cycle) in the denominator. Dropout-rates were analysed for consecutive complete cycles and consecutive embryo transfer cycles, because these two manners are used in reporting CLBRs, often related to the reimbursement policy.

Main results and the role of chance

This review included 29 studies and almost 800,000 patients from different countries and registries.

Regarding the patients who started their first IVF/ICSI cycle, trying to conceive their first child by IVF/ICSI, intrinsic dropout-rate was 33% (weighted average) after the first complete cycle, meaning they did not return for their second oocyte retrieval cycle. After the first embryo transfer cycle, intrinsic dropout-rate was 27% (weighted average), meaning those patients did not return for their next frozen-thawed embryo transfer cycle or for the next oocyte retrieval cycle. Regarding the patients who did not achieve a live birth after the first complete cycle, potential dropout-rate was 48% (weighted average), and 37% (weighted average) after the first embryo transfer cycle.

Both potential and intrinsic dropout-rates for both consecutive complete and embryo transfer cycles tended to increase with cycle number.

One study on second IVF/ICSI conceived children showed a potential dropout-rate after the first complete cycle of 29%. From studies on women &gt;40 years of age, the potential dropout-rate after the first complete cycle was 45% (weighted average) and from studies with the uses of testicular sperm extraction, the potential dropout-rate after the first complete cycle was 34% (weighted average).

Limitations, reasons for caution

Our analysis was hampered by the different ways of reporting on CLBRs (complete cycles versus embryo transfer cycles), informative censoring, patients changing clinics and spontaneous pregnancies. Dropout-rates were potentially overestimated given that spontaneous pregnancies were not taken into account.

Wider implications of the findings

The extent of dropout in IVF/ICSI treatment is substantial and has an important impact on its effectiveness. Therefore, it is a challenge for fertility centers to try to keep patients longer on board, by taking into account the patients’ preferences and managing their expectations.

Trial registration number

PROSPERO Registration number: CRD42020223512

Time intervals between semen production, initiation of analysis, and IUI significantly influence clinical pregnancies and live births

PURPOSE

Does IDEF mapping help monitor the technical process of IUI and explore the potential improvements which might contribute to increased pregnancy and live birth rates?

METHOD

Retrospective analysis of 1729 homologous IUI cycles of couples attending a fertility clinic in a university hospital setting. Standardized conventional semen parameters were analyzed and the semen samples prepared via discontinuous density gradient centrifugation.

RESULTS

There was no significant association between sperm concentration, motility and morphology (analysis phase), and pregnancy outcome. Only female and male ages were significantly associated with the pregnancy outcome. There was a significant difference in the odds on clinical pregnancies and live births when analysis was ≤ 21 min initiated, and < 107 min between sample production and IUI, adjusted for male and female age.

CONCLUSIONS

Adjusting for the couple's age, we could show that time intervals between semen production and analysis and IUI when kept low significantly influenced clinical pregnancies and live births.

DNA fragmentation in concert with the simultaneous assessment of cell viability in a subfertile population: establishing thresholds of normality both before and after density gradient centrifugation

PURPOSE

TUNEL assay is the most common, direct test for sperm chromatin integrity assessment. But, lack of standardized protocols makes interlaboratory comparisons impossible. Consequently, clinical thresholds to predict the chance of a clinical pregnancy also vary with the technique adopted. This prospective study was undertaken to assess the incidence of sperm DNA fragmentation in a subfertile population and to establish threshold values of normality as compared to a fertile cohort, both before and after density gradient centrifugation in the total and vital fractions.

METHOD

Men presenting at a university hospital setup for infertility treatment. DNA damage via TUNEL assay was validated on fresh semen samples, as conventional semen parameters, to reduce variability of results.

RESULTS

Total DNA fragmentation in the neat semen was significantly higher in the subfertile group, but the vital fraction was not significantly different between the two cohorts. After gradient centrifugation, DNA fragmentation increased significantly in the total fraction of the subfertile group but decreased significantly in the vital fraction. In the fertile cohort, there was a non-significant increase in total fragmentation and in the vital fraction the trend was unclear.

CONCLUSIONS

Estimating total and vital sperm DNA fragmentation, after density gradient centrifugation, increased both the sensitivity and the specificity, thereby lowering the number of false negatives and false positives encountered. These findings provide opportunities to investigate the significance of the total and the vital fractions after different assisted reproductive technologies.

Validating semen processing for an intrauterine program should take into consideration the inputs, actions and the outputs of the process

To validate semen preparation via density gradient centrifugation, we took into account the input via the semen sample, the action generated by technical and equipment characteristics and the output measured by the level of performance. Longer periods of abstinence reduced % yield, but increased viscosity and incomplete samples collected had no effect. Under controlled technical and equipment characteristics, precision and reproducibility were validated for density gradient. Additionally, as a good laboratory practice, internal and external quality control measures were implemented to guarantee the level of performance. Inseminating motile sperm count is an important predictive parameter for IUI success. In our group of patients, a yield of an absolute lower limit of 2 million motile spermatozoa was sufficient to contemplate IUI. Pregnancy rate of 13.8% where >2 million rapid progressive spermatozoa were inseminated was significantly higher than the pregnancies (4.4%) obtained with <2 million rapid progressive spermatozoa. This percentage was even higher than the national data registered for IUI (12.2%). To make IUI an attractive first-line treatment, standardization and proper validation of semen preparation procedure are mandatory.

How do cumulative live birth rates and cumulative multiple live birth rates over complete courses of assisted reproductive technology treatment per woman compare among registries?

STUDY QUESTION

How do the national cumulative (multiple) live birth rates over complete assisted reproduction technology (ART) courses of treatment per woman in Belgium compare to those in other registries?

SUMMARY ANSWER

Cumulative live birth rates (CLBRs) remain high with a low cumulative multiple live birth rate when compared with other registries and publications.

WHAT IS KNOWN ALREADY

In ART, a reduction in the multiple live birth rate could be achieved by reducing the number of embryos transferred. It has been shown that by doing so, live birth rates per cycle were maintained, particularly when the augmentation effect of attached frozen-thawed cycles was considered.

STUDY DESIGN, SIZE, DURATION

A retrospective cohort study included all patients with a Belgian national insurance number who were registered in the national ART registry (Belrap) and who started a first fresh ART cycle between 1 July 2009 until 31 December 2011 with follow up until 31 December 2012. We analysed 12 869 patients and 38 008 cycles (both fresh and attached frozen cycles).

PARTICIPANTS, MATERIALS, SETTINGS, METHODS

CLBRs per patient who started a first ART cycle including fresh and consecutive frozen cycles leading to a live birth. Conservative estimates of cumulative live birth assumed that patients who did not return for treatment had no chance of achieving an ART-related live birth, whereas optimal estimates assumed that women discontinuing treatment would have the same chance of achieving a live birth as those continuing treatment. A maximum of six fresh ART cycles with corresponding frozen cycles was investigated and compared with other registries and publications.

MAIN RESULTS AND ROLE OF CHANCE

The CLBR was age dependent and declined from 62.9% for women <35 years, to 51.4% for women 35-37 years, to 34.1% for women 38-40 years and 17.7% for women 41-42 years in the conservative analysis after six cycles. In the optimal estimate, the CLBR declined from 85.9% for women <35 years, to 72.0% for women 35-37 years, to 50.4% for women 38-40 years and 36.4% for women 41-42 years. The cumulative multiple live birth rates for the whole population were 5.1 and 8.6% for the conservative and optimal estimate, respectively.

LIMITATIONS, REASONS FOR CAUTION

Conservative and optimal estimates use assumptions for the whole ART population and do not take the individual patient into account.

WIDER IMPLICATIONS OF THE FINDINGS

These data reinforce the validity of the Belgian model of coupling reimbursement of ART costs to a restriction in the number of embryos transferred. Our data can improve decision-making in medical ART practice both on the patient level and for society at large and could provide health care takers and insurance companies with a valid model.

STUDY FUNDING COMPETING INTERESTS

none.

Vitrification of cleavage stage day 3 embryos results in higher live birth rates than conventional slow freezing: a RCT

STUDY QUESTION

Is the live birth rate (LBR) per embryo thawed/warmed higher when Day 3 cleavage stage embryos are cryopreserved by vitrification compared with slow freezing?

SUMMARY ANSWER

The LBR per embryo thawed/warmed was higher after vitrification than after slow freezing on Day 3, based on better embryo survival, quality and availability of embryos in the vitrification group.

WHAT IS KNOWN ALREADY

Post-thawing survival rate of cleavage-stage embryos has been reported to be higher after vitrification than after slow freezing.

STUDY DESIGN, SIZE, DURATION

This RCT was performed in an academic tertiary center between September 2011 and March 2013. If supernumerary embryos were available on Day 3, patients were randomized at the time of cryopreservation using a computerized system to determine a simple allocation to the vitrification group or the slow freezing group and all embryos were frozen with the same technique. The primary outcome of this study was the LBR per embryo thawed/warmed. Power calculation revealed that 184 thawed embryos were needed in each group (β = 0.8, α < 0.05) to test the hypothesis that the LBR per embryo thawed/warmed was significantly higher (16%) after vitrification than after slow freezing (6%).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Patients <40 years old undergoing their first oocyte retrieval (OR), with embryo transfer and with supernumerary embryos on Day 3, were randomized. Day 3 embryos with ≥6 cells, <25% fragmentation and morphologically equal blastomeres were cryopreserved by slow freezing (using 1,2-propanediol and 0.1 M sucrose as cryoprotectant) or by closed vitrification using commercially available freezing/vitrification media. Survival was defined as ≥50% cells were intact after thawing. Thawed embryos were further cultured overnight. In total, 307 patients were randomized to slow freezing (155 patients, 480 embryos) or vitrification (152 patients, 495 embryos).

MAIN RESULTS AND THE ROLE OF CHANCE

By March 2013, 200 embryos were thawed after slow freezing in 95 cycles for 79 patients and 217 embryos were warmed after vitrification in 121 cycles in 90 patients. The LBR per embryo thawed/warmed was significantly higher after vitrification (16.1% (35/217)) than after slow freezing (5.0% (10/200); P < 0.0022; relative risk (RR) 3.23; 95% confidence interval (CI) 1.64-6.35). Similarly, the implantation rate per embryo thawed/warmed was higher after vitrification (20.7% (45/217) than after slow freezing (7.5% (15/200); P = 0.0012; RR 2.76; CI 1.59-4.81). The survival rate was significantly higher after vitrification (84.3% (183/217) than after slow freezing (52.5% (105/200); P < 0.0001). Significantly more embryos were fully intact after vitrification (75.4% (138/183) than after slow freezing (28.6% (30/105); P < 0.0001). The number of transfers was significantly higher after vitrification (90.1% (109/121)) than after slow freezing (73.7% (70/95); P = 0.0024).

LIMITATIONS, REASONS FOR CAUTION

Survival rates in the slow freezing group were low in this study. Additional RCTs are needed to compare reproductive outcome after vitrification and after slow freezing with 1,2-propanediol and 0.2 M sucrose, since this method has been reported to have better survival than the method used in our study. Our findings are only applicable to the specific slow freezing cryopreservation medium used in our study, and not to any other commercially available media.

WIDER IMPLICATIONS OF THE FINDINGS

When compared with slow freezing using 1,2-propanediol and 0.1 M sucrose as cryoprotectant, vitrification of Day 3 cleavage stage embryos resulted in a higher LBR per embryo warmed, and may therefore result into a higher cumulative delivery rate after one oocyte retrieval.

STUDY FUNDING/COMPETING INTERESTS

None.

TRIAL REGISTRATION NUMBER

NCT02013024.

The impact of legally restricted embryo transfer and reimbursement policy on cumulative delivery rate after treatment with assisted reproduction technology

STUDY QUESTION

What is the impact of the Belgian legislation (1 July 2003), coupling reimbursement of six assisted reproduction technology (ART) cycles per patient to restricted embryo transfer policy, on cumulative delivery rate (CDR) per patient?

SUMMARY ANSWER

The introduction of Belgian legislation in ART had no negative impact on the CDR per patient based on realistic estimates within six cycles or 36 months.

WHAT IS KNOWN ALREADY

The introduction of Belgian legislation limiting the number of embryos for transfer resulted in a reduction of the multiple pregnancy rate (MPR) per cycle by 50%.

STUDY DESIGN, SIZE, DURATION

A retrospective cohort study with a study group after implementation of the new ART legislation (July 2003 to June 2006) and the control group, before legislation (July 1999 to June 2002).

PARTICIPANTS/MATERIALS, SETTING, METHODS

CDR was compared in an academic tertiary setting between a study group after legislation (n = 795 patients, 1927 fresh and 383 frozen-thawed embryo transfer (FET) cycles) and a control group before legislation (n = 463 patients, 876 fresh and 185 FET cycles) within six cycles or 36 months, delivery or discontinuation of treatment. The CDR was estimated using life table analysis considering pessimistic, optimistic and realistic scenarios and compared after adjustment for confounding variables. In the realistic scenario we included information on embryo quality to define the prognosis of each patient discontinuing treatment.

MAIN RESULTS AND THE ROLE OF CHANCE

In the realistic scenario, CDR within 36 months was comparable (all ages, P = 0.221) in study group (60.8%) and control group (65.6%), as well as in different age groups (<36 years, P = 0.242; 36-39 years, P = 0.851; 40-42 years, P = 0.840). In the realistic scenario applied to six cycles, we found lower CDRs in the study group than in the control group within the two first cycles (all ages, P = 0.009; <36 years, P = 0.007) but no difference in CDRs between the two groups within the four subsequent cycles (all ages P = 0.232; <36 years, P = 0.198). The CDR within six cycles was 60 and 65.3% for study group and control group, respectively, for all ages, and 65.8 and 70.4%, respectively, in the subgroup younger than 36 years. In women ≥36 years, CDR within six cycles was comparable in both groups (36-39 years, 43% in study versus 44.4% in control group, P = 0.730; 40-42 years, 21% in study versus 23% in control group, P = 0.786).

LIMITATIONS, REASONS FOR CAUTION

A retrospective cohort study design was the only way to study the impact of legislation on CDR. Owing to the retrospective nature of this analysis over a long period of time, our data are potentially influenced by improvements in techniques and therefore improved success rates in ART over time.

WIDER IMPLICATIONS OF THE FINDINGS

This 'Belgian model' can now be considered for application worldwide in countries with the aim to reduce the main ART side effect (high MPR) and its associated costs without a negative effect on the main intended effect (high CDR).

STUDY FUNDING/COMPETING INTEREST(S)

The authors have no conflict of interest to declare. No funding was obtained for this study.

The history of Belgian assisted reproduction technology cycle registration and control: a case study in reducing the incidence of multiple pregnancy

STUDY QUESTION

What is the effect of a legal limitation of the number of embryos that can be transferred in an assisted reproductive technology (ART) cycle on the multiple delivery rate?

SUMMARY ANSWER

The Belgian national register shows that the introduction of reimbursement of ART laboratory costs in July 2003, and the imposition of a legal limitation of the number of embryos transferred in the same year, were associated with a >50% reduction of the multiple pregnancy rate from 27 to 11% between 2003 and the last assessment in 2010, without any reduction of the pregnancy rate per cycle.

WHAT IS KNOWN ALREADY

Individual Belgian IVF centres have published their results since the implementation of the law, and these show a decrease in the multiple pregnancy rate on a centre by centre basis. However, the overall national picture remains unpublished.

STUDY DESIGN, SIZE, DURATION

Cohort study from 1990 to 2010 of all ART cycles in Belgium (2685 cycles in 1990 evolving to 19 110 cycles in 2010), with a retrospective analysis from 1990 to 2000 and prospective online data collection since 2001.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Registration evolved from paper written reports per centre to a compulsory online registration of all ART cycles. From 2001 up to mid-2009, data were collected from Excel spread sheets or MS Access files into an MS Access database. Since mid-2009, data collection is done via a remote and secured web-based system (www.belrap.be) where centres can upload their data and get immediate feedback about missing data, errors and inconsistencies.

MAIN RESULTS AND THE ROLE OF CHANCE

National Belgian registration data show that reimbursement of IVF laboratory costs in July 2003, coupled to a legal limitation in the number of embryos transferred in utero, were associated with a 50% reduction of the multiple pregnancy rate from 27 to 11% without reduction of the pregnancy rate per cycle, and with an increase in the number of fresh and frozen ART cycles due to improved access to treatment.

LIMITATIONS, REASONS FOR CAUTION

There is potential underreporting of complications of ART treatment, pregnancy outcome and neonatal health.

WIDER IMPLICATIONS OF THE FINDINGS

Over the 20 years of registration, the pregnancy rate has remained constant, despite the reduction in the number of embryos transferred, optimization of laboratory procedures and stimulation protocols, introduction of quality systems and implementation of the EU Tissue Directive over the period 2004-2010.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was sought for this study. None of the authors has any conflict of interest to declare.

Quality indicators for all dimensions of infertility care quality: consensus between professionals and patients

STUDY QUESTION

What is the relative importance of the six dimensions of quality of care according to different stakeholders and can a quality indicator set address all six quality dimensions and incorporate the views from professionals working in different disciplines and from patients?

SUMMARY ANSWER

Safety, effectiveness and patient centeredness were the most important quality dimensions. All six quality dimensions can be assessed with a set of 24 quality indicators, which is face valid and acceptable according to both professionals from different disciplines and patients.

WHAT IS KNOWN ALREADY

To our knowledge, no study has weighted the relative importance of all quality dimensions to infertility care. Additionally, there are very few infertility care-specific quality indicators and no quality indicator set covers all six quality dimensions and incorporated the views of professionals and patients.

STUDY DESIGN, SIZE AND DURATION

A three-round iterative Delphi survey including patients and professionals from four different fields, conducted in two European countries over the course of 2011 and 2012.

PARTICIPANTS/MATERIALS, SETTINGS AND METHODS

Dutch and Belgian gynaecologists, embryologists, counsellors, nurses/midwifes and patients took part (n = 43 in round 1 and finally 30 in round 3). Respondents ranked the six quality dimensions twice for importance and their agreement was evaluated. Furthermore, in round 1, respondents gave suggestions, which were subsequently uniformly formulated as quality indicators. In rounds 2 and 3, respondents rated the quality indicators for preparedness to measure and for importance (relation to quality and prioritization for benchmarking). Providing feedback allowed selecting indicators based on consensus between stakeholder groups. Measurable indicators, important to all stakeholder groups, were selected for each quality dimension.

MAIN RESULTS

All stakeholder groups and most individuals agreed that safety, effectiveness and patient centeredness were the most important quality dimensions. A total of 498 suggestions led to the development of 298 indicators. Professionals were sufficiently prepared to measure 204 of these indicators. Based on importance, 52 (7-15 per dimension; round 2) and finally 24 (4 per dimension; round 3) quality indicators were selected.

LIMITATIONS, REASONS FOR CAUTION

The final quality indicator set does not cover the entire care process, but rather takes a 'sample' of each quality dimension. Although the quality indicators are face valid and acceptable, their psychometric characteristics need to be tested by further research.

WIDER IMPLICATIONS OF THE FINDINGS

Quality management should focus on safety, effectiveness and patient centeredness of care. Clinics can use the quality indicator set to assess all quality dimensions of their care.

Semi-automated morphometric analysis of human embryos can reveal correlations between total embryo volume and clinical pregnancy

STUDY QUESTION

Is there a link between morphometric characteristics measured by a computer-assisted scoring system and clinical pregnancy outcome?

SUMMARY ANSWER

The results confirm that computer-assisted assessment of the total embryo volume is associated with clinical pregnancy outcome and can be used to complement current procedures of embryo selection.

WHAT IS KNOWN ALREADY

Morphometric analysis of a large group of embryos has revealed the potential to optimize algorithms for image-analysis systems for the grading of embryos and predicting pregnancy outcomes.

STUDY DESIGN, SIZE, DURATION

Oocytes and embryos were obtained from 458 patients who underwent single embryo transfer on Day 3 after IVF/ICSI, between September 2006 and December 2010 at the Leuven University Fertility Center, Belgium. In total, the data set contained 2796 embryos including 458 embryos that were transferred on Day 3. Ongoing pregnancy was defined as the presence of at least one intrauterine gestational sac at 20 weeks.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Patients included in this study were younger than 36 years, entering their first (n = 375) or second (n = 83) IVF/ICSI cycle and were only included once. Patients were excluded if the cycle included biopsy for PGD or if donor sperm/donor oocytes were used. Based on the 26 sequential images of the same embryo taken at one time point in different planes, the software calculates the total cytoplasmic volume for each time point, from which any reduction or change in the volume with time can be assessed (which helps interpret the degree of fragmentation) and the size of blastomeres. The diameter of the smallest and largest blastomere and the total volume of each embryo were extracted from the computer-assisted scoring system database and the coefficient of diversity was calculated for Days 1, 2 and 3. A logistic regression analysis was performed to determine the range of embryo volume associated with an increased chance of pregnancy.

MAIN RESULTS AND THE ROLE OF CHANCE

On Day 3, blastomeres of 8-cell stage embryos were less divergent in size than those of 6-, 7-, 9-cell stage embryos. Although, the coefficients of diversity (ratio of the largest:smallest blastomeres) of implanted embryos tended to be lower than for non-implanted embryos, the difference was only significant for 6-cell stage embryos (P = 0.02). After logistic regression, an association between total embryo volume and pregnancy was observed which had a quadratic nature: both lower and higher volumes were associated with a lower probability of successful pregnancy. A significant association was identified between total embryo volume and pregnancy rate on both Days 2 (P = 0.003) and 3 (P = 0.0003). Diagnostic measures (sensitivity, specificity, positive predictive value, accuracy and c-statistics) of the defined volume range were relatively poor. However, results showed a good negative predictive value [76.86% (95% confidence interval 71.03-82.02) on Day 3].

LIMITATIONS, REASONS FOR CAUTION

A general disadvantage of studies evaluating the impact of a characteristic on the implantation potential of an embryo is the fact that the best embryo is chosen for transfer. No comparisons can therefore be made with the other embryos. Moreover, the decision process is currently based on a non-automated, standard scoring system, which means that a 'bias' in the selection process is always present.

WIDER IMPLICATIONS OF THE FINDINGS

Our results are an important step towards the development of an automated computer-assisted scoring system for the morphological characteristics of human embryos to improve embryo selection for optimizing implantation potential. Total embryo volume appears to be one of the objective characteristics that should be included.

STUDY FUNDING/COMPETING INTEREST(S)

None.

TRIAL REGISTRATION NUMBER

Not applicable.

Dutch translation of the ICMART-WHO revised glossary on ART terminology

BACKGROUND

A standardized set of definitions was needed in the field of medically assisted reproduction (MAR) to standardize and harmonize international data acquisition and to monitor the availability, efficacy, and safety of assisted reproductive technology (ART) worldwide. In order to provide accurate national data, the use of a terminology list which was composed and negotiated by the International Committee for Monitoring Assisted Reproductive Technology (ICMART) is essential, and a translation into Dutch was crucial for its implementation in Belgium and the Netherlands.

METHOD

The authors of the Dutch article translated the English publication that appeared simultaneously in Human Reproduction and Fertility and Sterility in 2009. A consensus text was obtained after evaluation by experts in the field of MAR both in the Netherlands and in Belgium and then by the board of the respective organizations of obstetrics and gynecology. It was then sent to the World Health Organization (WHO) for approval of publication.

RESULT

A translation into Dutch of the ICMART terminology of 2009 was obtained after consensus was reached on clinical and laboratory procedures, outcome variables, and birth.

CONCLUSION

The availability and use of standardized terminology and its translation into Dutch will add to a more standardized communication between professionals responsible for the practice of ART and for those responsible for national, regional, and international registries.

BMI-related metabolic composition of the follicular fluid of women undergoing assisted reproductive treatment and the consequences for oocyte and embryo quality

STUDY QUESTION

Is the metabolic composition of the follicular fluid of women undergoing assisted reproductive treatment (ART) related to serum composition and BMI and is it associated with oocyte and embryo quality?

SUMMARY ANSWER

We showed that metabolic alterations in the serum are reflected in the follicular fluid and that some of these alterations may affect oocyte quality, irrespective of BMI.

WHAT IS KNOWN ALREADY

Many studies have focused on the effect of metabolic disorders, such as obesity and type 2 diabetes, on assisted reproduction outcomes. There are, however, only few studies focusing on the importance of the correlation between serum and follicular fluid compositions and the composition of the follicular fluid as the oocyte's micro-environment, affecting its development and subsequent embryo quality.

DESIGN, PARTICIPANTS AND SETTING

In this prospective cohort study, patient information, fertility treatment outcome data, follicular fluid and serum were obtained from women undergoing ART. Patients were categorized according to their BMI (kg/m(2)) as normal (n = 60), overweight (n = 26) or obese (n = 20). Serum and follicular fluid samples were analyzed for urea, total protein, albumin, cholesterol, high-density lipoprotein cholesterol, triglycerides, non-esterified fatty acids, apolipoprotein A1, apolipoprotein B, glucose, lactate, C-reactive protein, insulin-like growth factor -1 (IGF-1), IGF-binding protein 3 (only in follicular fluid), free carnitine and total carnitine. Metabolite concentrations in serum and follicular fluid samples were correlated and were associated with BMI and fertility treatment outcome.

MAIN RESULTS

Most serum metabolite differences between patients were reflected in the follicular fluid (P < 0.05). Follicular fluid apolipoprotein A1 and follicular fluid total protein concentrations negatively affected oocyte quality parameters (P < 0.05). However, overall BMI-related associations were poor.

BIAS, CONFOUNDING AND OTHER REASONS FOR CAUTION

In this study, we included every patient willing to participate. Within this cohort, women with a BMI transcending 35 kg/m(2) were scarce (n = 2), because extremely overweight women are mostly advised to lose weight before starting ART. Furthermore, the number of patients in each BMI group was different, possibly masking associations between the metabolic composition of serum and follicular fluid and oocyte quality parameters.

GENERALIZABILITY TO OTHER POPULATIONS

There were significant associations indicating that metabolic changes in the serum are reflected in the follicular fluid, potentially affecting oocyte quality, irrespective of the patient's BMI. For ethical reasons, this study only focused on women already in need of artificial reproductive treatment. From a metabolic point of view, we consider this cohort as a representative sample of all women of reproductive age.

STUDY FUNDING

This study was funded by the special research fund, university of Antwerp (BOF UA). None of the authors has any conflict of interest to declare.

The obstetrical and neonatal outcome of babies born after single-embryo transfer in IVF/ICSI compares favourably to spontaneously conceived babies

BACKGROUND

Recently, concern has risen about poor obstetrical and neonatal outcome of singletons after IVF/ICSI. Because the population of patients receiving single-embryo transfer (SET) resulting in singleton pregnancies is different from the one that would have become pregnant (with a singleton) before SET was introduced, we wanted to investigate whether the outcome of singleton pregnancies after SET differed from spontaneously conceived singletons.

METHODS

The obstetrical and early neonatal outcome of all pregnancies originating from SET after IVF/ICSI procedures between 1 January 1998 and 31 December 2003, was prospectively collected and analyzed.

RESULTS

Data from 251 singleton pregnancies and births after SET were analyzed and compared to data from 59,535 spontaneously conceived singletons retrieved from the Centre for Perinatal Epidemiology. The mean birthweight of the singletons after SET was 3322 g (+/-538 SD) versus 3330 g (+/-531 SD) for the spontaneously conceived singletons (P = 0.82). The mean gestational age was 38.7 weeks (+/-1.9 SD) for SET and 38.9 weeks (+/-1.8 SD) for spontaneously conceived singletons (P = 0.06). The proportion of very preterm birth (<32 weeks) was 0.8% in each group, and the proportion of preterm birth (<37 weeks) was 10.0% for SET singletons and 6.24% for spontaneous singletons (P = 0.03). However, mean birthweight of very preterm, preterm and term SET singleton babies was similar to the mean birthweight in every category of gestational age in the spontaneous conceived control group. Stillbirth was 0.4% for both populations (P = 0.99).

CONCLUSIONS

Good prognosis patients, in whom SET is applied, do not only have a higher chance of conception but do not have an unfavourable outcome of their singleton baby when compared to spontaneous singletons.

What about the remaining twins since single-embryo transfer? How far can (should) we go?

Single-embryo transfer (SET) and more specifically elective SET (eSET) have taken their place in good clinical IVF/ICSI practice. After the initial cautious search for the characteristics of the twin-prone patient and of the selection of the embryo with the highest implantation potential many centres have embarked on the (progressive) implementation of SET, either by conviction or forced by legislation or both. It was only because the ongoing pregnancy rates remained largely unaffected that SET was accepted. Generally speaking, it can be said that the twinning rate after IVF/ICSI has dropped by at least 50% simply by transferring only one good-quality embryo in the first and second fresh IVF/ICSI cycles in young women, without decrease in the overall pregnancy rate. Preventing 'the second half' of IVF/ICSI twins constitutes another and probably tougher challenge because the target group is a heterogeneous mix consisting of patients in very different clinical situations. Can we expand our experience for further twin prevention to women of older age and to cycles of higher rank without a significant drop in pregnancy rates? Can we extend it to more cryopreservation cycles? To have an idea of future target groups for increased application of SET, we analysed the remaining twins after double-embryo transfer (DET), and from these data we suggest expanding the eSET policy to women <38 years of age until the third cycle and to cryopreservation cycles.

Single top quality embryo transfer as a model for prediction of early pregnancy outcome

BACKGROUND

Single embryo transfer (particularly of a top quality embryo) is an excellent model to correlate embryo quality in terms of morphological criteria to early pregnancy. We investigated whether this model could provide us with more information on what happens after implantation in the first trimester of pregnancy.

METHODS

The outcome of 370 consecutive single top quality embryo transfers in patients younger than 38 years was analysed for pregnancy and first-trimester pregnancy loss (FTPL) before 13 weeks of gestation. Analysis was done on each cohort of embryos from which the transferred top quality embryo was selected. Serum HCG levels were measured on day 8 and day 12 after day 3 embryo transfer. The HCG index was calculated as the level of HCG on day 12/HCG on day 8.

RESULTS

The pregnancy rate after single top quality embryo transfer was 51.9%. This was independent of the patients' age. FTPL, however, appeared to be age dependent: 15.4% for the whole group, 9% in patients younger than 30 years and 19% in patients above 30 years. The pregnancy rate was 50% in IVF cycles and 52% in ICSI cycles; FTPL was 19% in IVF cycles and 10% in ICSI cycles. Multiple regression analysis showed that these differences originated from age differences between both populations rather than from technique-related factors. An HCG level >or=45 IU/l on day 12 was predictive for ongoing pregnancy with 75.6% sensitivity and 100% specificity; an HCG index >or=3.5 similarly predicted ongoing pregnancy with 72.3% sensitivity and 100% specificity.

CONCLUSIONS

These data show that embryo selection for transfer on day 3 can be used as an excellent tool for prediction of pregnancy but not for prediction of FTPL. The pregnancy rate of a single top quality embryo is not related to age, whereas FTPL is age dependent.

A real-life prospective health economic study of elective single embryo transfer versus two-embryo transfer in first IVF/ICSI cycles

BACKGROUND

We analysed the difference in maternal, neonatal and total costs after single (SET) versus double day 3 embryo transfer (DET).

METHODS

We performed a two-centre prospective study of women in their first IVF/ICSI cycle choosing between SET or DET. Infertility treatment data were gathered from a database; maternal and neonatal outcome data from a case report form (CRF); health economic data from medical acts registered in the CRF for the outpatient part and from hospital bills. SET was performed in 206/367 (56.1%) and DET in 161/367 (43.9%) women.

RESULTS

In all, 367 transfers yielded 186 positive pregnancy tests, 148 ongoing pregnancies and 136 live deliveries (50.7, 40.3 and 37.1% per embryo transfer) of which 15 (11.0%) were twins. Live birth rate was 37.4% for SET, 36.6% for DET. Intention-to-treat analysis showed differences for: duration of pregnancy (SET: 39.0 +/- 1.4 versus DET: 38.3 +/- 2.2 weeks; P = 0.055), percentage prematurity (8.5 versus 23.8%; P = 0.033), percentage of neonates hospitalized (5.7 versus 17.9%; P = 0.121) and duration of neonatal hospitalization (6.3 +/- 2.2 versus 10.3 +/- 10.1 days; P = 0.01). Total cost after DET was higher (SET: 4700 +/- 3239 versus DET: 8613 +/- 10 105; P = 0.105), due to significantly higher neonatal costs (451 +/- 957 versus 3453 +/- 8154; P < 0.001) and not to differences in maternal costs (4250 +/- 2882 versus 5160 +/- 4106; P = 0.152).

CONCLUSIONS

This prospective health economic study shows that transfer of a single top quality embryo is equally effective as, but substantially cheaper than, double embryo transfer in women <38 years of age in their first IVF/ICSI cycle.

[Prevention of twin pregnancy after IVF/ICSI using embryo transfer]

One of the negative aspects of in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) is the increased risk of multiple pregnancies. Multiples of high order (triplets and pregnancies of higher order) are obsolete to both doctors and patients and need to be avoided. However, there is an epidemic of twin pregnancies with a higher risk of obstetric, perinatal and neonatal complications than singleton pregnancies and with an important psychosocial, economic and financial impact for the parents to be. A reduction in the number of twins can only be obtained by transfer of one embryo. If this guideline would be applied to all cycles, a dramatic fall in pregnancy rate would occur. In a selected patient group one selected embryo with an excellent implantation potential can be transferred.

Cryopreservation as a tool to reduce multiple birth

The potential role of embryo cryopreservation from the point of view of prevention of multiple pregnancies is analysed. Cryopreservation is an unavoidable option in stimulated IVF/intracytoplasmic sperm injection (ICSI), but at the same time an underestimated tool in the prevention of twins. There is a need for an evaluation system not only of the cryotechnology process per se, but also of the true augmenting effect of cryopreservation on the total reproductive potential of a single oocyte harvest. Only cryopregnancies occurring after an unsuccessful fresh cycle (possibly followed by one or more unsuccessful freeze-thaw cycles with embryos from the same harvest) truly reflect the augmentation potential of cryopreservation. This potential is greater than generally thought. First, the efficacy of cryopreservation is suboptimal with survival rates between 30 and 70%. Second, if single-embryo transfer were applied in a much larger proportion of cycles than is presently the case, more embryos would be available for cryopreservation, resulting in more and more successful freeze-thaw cycles. In the future, the combination of elective single-embryo transfer with an optimized cryopreservation programme is likely to become the standard of care for routine IVF/ICSI treatment.

Impact of patients' choice for single embryo transfer of a top quality embryo versus double embryo transfer in the first IVF/ICSI cycle

BACKGROUND

The aim of this study was to evaluate the impact of transferring a single top quality embryo in the first IVF/ICSI cycle of patients <38 years old who chose to have one or two embryos transferred.

METHODS

A total of 262 patients participated in the study, and 243 transfers were performed: 156 (64%) patients chose the transfer of a single top quality embryo, if available, and two non-top quality embryos if not available; 87 (36%) patients chose to have a double embryo transfer regardless of embryo quality.

RESULTS

In the first group an ongoing pregnancy rate of 40% (63/156) with a twin pregnancy rate of 2% (1/63) was achieved. In the second group the ongoing pregnancy rate was 44% (38/87) with 26% (10/38) twin pregnancies. In the patient group with only one embryo transferred, irrespective of the patient's choice, the ongoing pregnancy rate was 43% (54/127) with no twin pregnancies. For the study population as a whole, the ongoing pregnancy rate was 42% (101/243) with 11% (11/101) twins.

CONCLUSION

We conclude that the introduction of single embryo transfer in the first IVF/ICSI cycle is highly acceptable in women <38 years old.

Prevention of twin pregnancy after in-vitro fertilization or intracytoplasmic sperm injection based on strict embryo criteria: a prospective randomized clinical trial

A prospective randomized study comparing single embryo transfer with double embryo transfer after in-vitro fertilization or intracytoplasmic sperm injection (IVF/ICSI) was carried out. First, top quality embryo characteristics were delineated by retrospectively analysing embryos resulting in ongoing twins after double embryo transfer. A top quality embryo was characterized by the presence of 4 or 5 blastomeres at day 2 and at least 7 blastomeres on day 3 after insemination, the absence of multinucleated blastomeres and <20% cellular fragments on day 2 and day 3 after fertilization. Using these criteria, a prospective study was conducted in women <34 years of age, who started their first IVF/ICSI cycle. Of 194 eligible patients, 110 agreed to participate of whom 53 produced at least two top quality embryos and were prospectively randomized. In all, 26 single embryo transfers resulted in 17 conceptions, 14 clinical and 10 ongoing pregnancies [implantation rate (IR) = 42.3%; ongoing pregnancy rate (OPR) = 38.5%] with one monozygotic twin; 27 double embryo transfers resulted in 20 ongoing conceptions with six (30%) twins (IR = 48.1%; OPR = 74%). We conclude that by using single embryo transfer and strict embryo criteria, an OPR similar to that in normal fertile couples can be achieved after IVF/ICSI, while limiting the dizygotic twin pregnancy rate to its natural incidence of <1% of all ongoing pregnancies.

Characterization of a top quality embryo, a step towards single-embryo transfer

In most in-vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) programmes approximately one ongoing pregnancy in three is multiple. The need to characterize embryos with optimal implantation potential is obvious. We retrospectively examined all of 23 double transfers resulting in ongoing twins, occurring between January 1, 1996 and May 19, 1997. Characteristics of these top quality embryos were absence of multinucleated blastomeres, four or five blastomeres on day 2, seven or more cells on day 3, and </=20% anucleated fragments. In a subsequent series of 400 IVF/ICSI cycles (out of which 372 were selected for embryo transfer) from May 20, 1997 to July 31, 1998, only women <38 years of age had multiple pregnancies: after 221 transfers of two embryos, 45/116 (39%) were multiple, and after 77 transfers of >2 embryos, 11/31 (35%) were multiple. We applied our top quality criteria to the 221 double transfers: 106 transfers with two top embryos resulted in 65 (63%) ongoing pregnancies with 37 (57%) twins, 65 transfers with one top embryo in 38 (58%) ongoing pregnancies with eight (21%) twins. In the group without top embryos, 12/52 (23%) ongoing singletons occurred, with no twins. The corresponding ongoing implantation rates were 49, 35 and 12%. This analysis suggests that single embryo transfer with an acceptable pregnancy rate might be considered if a top quality embryo is available.

Quantification of insulin-like growth factor I receptors on granulosa cells with flow cytometry after follicular stimulation

The presence of insulin-like growth factor I (IGF-I) receptors on granulosa cells was investigated by flow cytometric analysis. Granulosa cells were retrieved from follicular fluid after oocyte retrieval during assisted reproduction technology procedures. Whole samples of follicular fluid were pooled and the cellular fraction analysed. In order to analyse granulosa cells only we developed a dual labelling technique whereby granulosa cells were identified as CD45 negative cells, distinguishing them from leukocytes which are CD45 positive. Analysis of the IGF-I receptor was done by staining the sample with a monoclonal anti-IGF-I receptor antibody (alphaIR3 clone) and goat anti-mouse phycoerythrin labelled antibody. After identification of the presence of IGF-I receptors, receptor expression was quantified by calibration of the fluorescence signals. We analysed 10 patients' samples and showed 559-1774 binding sites per granulosa cell with a mean value of 1125 +/- 382 (SD).

Flow cytometric analysis of granulosa cells from follicular fluid after follicular stimulation

Granulosa cells are not easily accessible, unless they are examined in follicular fluid after oocyte retrieval. These samples are usually contaminated with blood. We have set up a general technique for analysis of granulosa cells without physically separating them from blood cells. The sample is stained with CD45, which is a pan-leukocyte marker, and granulosa cells are consecutively selected as CD45 negative during flow cytometric analysis. Analysis of forward scatter of the granulosa cells, which is correlated to cell size, shows a wide size range throughout the whole population rather than two distinct populations as previously suggested.