The effect of intracytoplasmic sperm injection and semen parameters on blastocyst development in vitro

What sperm parameters effect blastocyst formation and quality during ICSI with severe male infertility

Sperm-derived genetic material contributes half of the genome to the embryo, hence it's crucial to investigate which sperm parameter influences blastocyst formation in the intracytoplasmic sperm injection (ICSI) cycles with severe male infertility. The retrospective study analyzed 296 ICSI cycles with severe oligoasthenoteratozoospermia (OAT) and 99 ICSI cycles with preimplantation genetic testing for aneuploidy (PGT-A). Following the correlation analysis, data stratifications were performed in the OAT ICSI subgroup. The results showed that the matching blastocyst in the OAT ICSI cycles had inferior sperm parameters. DFI and sperm morphology had an influence on the blastocyst formation rate and the high-quality blastocysts formation rate on Day6, but no significant effect on the blastocyst development on Day 5. The high-quality blastocysts formation rate and ratio of high-quality blastocyst on Day 6 were demonstrably better in the subgroup of the teratozoospermic morphology when DFI was within the normal range. In the case of the normal sperm morphology, no statistically significant difference was found in blastocyst development, although there were numerical differences within different DFI subgroups. It was concluded that the blastocyst quality and development declined with the decreased sperm qualities.

Sperm Selection Using Zona Pellucida-Binding Enhanced Embryo Morphokinetic and Clinical Outcomes in ICSI: A Sibling Oocytes Study

The objective was to investigate the embryo morphokinitics using a time-lapse monitoring (TLM) system and assessment of clinical outcomes following intracytoplasmic sperm injection (ICSI) with zona pellucida (ZP)-bound sperm selection and conventional methods. A total of 371 metaphase II (MII) oocytes from 50 ICSI cycles were studied. Sibling oocytes were randomly divided into control (n = 199) and ZP-bound group (n = 172). All resulting zygotes were cultured and monitored in the TLM system up to Day 3 after ICSI. Fertilization rate, early embryo development, and clinical outcomes were evaluated. No significant differences were found in fertilization rate, time-lapse qualitative and quantitative measures, pronuclear fading time (PNF) t2, t3, t4, t5, t6, and t7 (times of cleavage to 2, 3, 4, 5, 6, and 7 cells), respectively. However, the t8 (time of cleavage to eight cells) and cc3 (duration of third cell cycle) revealed a significant difference between control and ZP-bound groups (p < .05). A significant difference between the two groups (p < .05) in the rates of Grade A embryos (according to Basile algorithm), chemical pregnancy, clinical pregnancy, and implantation was observed. Sperm selection using biological materials, such as ZP, improved both embryo quality and pregnancy outcomes, despite not affecting the early embryo development and morphokinetic parameters up to t8. This prospective randomized sibling oocyte trial was registered in October 2020 to January 2022 (IRCT20200705048021N1).

Comparison of clinical outcomes between conventional in vitro fertilization and intracytoplasmic sperm injection in poor responders with only single oocyte retrieved

OBJECTIVE

To compare the clinical outcomes between conventional insemination (IVF) and intracytoplasmic sperm injection (ICSI) in poor responders with only a single oocyte retrieved.

MATERIALS AND METHODS

This is a retrospective case-control study. Couples who were treated with assisted reproductive technology (ART) with a single oocyte retrieved in Mackay Memorial Hospital from 1996 to 2016 were recruited. All data were categorized into three groups, according to their fertilization method and semen quality: group A, conventional insemination with non-male factor (IVF-NMF, n = 115), group B, ICSI with male factor (ICSI-MF, n = 30), and group C, ICSI with non-male factor (ICSI-NMF, n = 49).

RESULTS

No statistically significant difference was observed between IVF and ICSI groups in pregnancy outcomes, including the chemical or clinical pregnancy rate, miscarriage rate, and live birth rate. Similar fertilization rates per oocyte obtained were observed in IVF and ICSI patients, but significantly lower per mature oocyte in the ICSI group (IVF: 91.5%, ICSI-MF: 75.0%, ICSI-NMF: 77.8%). Although there is no statistical significance, the lower live birth rate is observed in group C than others (A:11.5%, B:25%, C:5%, p = 0.187).

CONCLUSION

In this study, pregnancy outcomes of conventional in vitro fertilization and ICSI in poor responders with only a single oocyte retrieved were similar. However, the fertilization rate of matured oocytes in ICSI groups is significantly lower than that in the IVF group, indicating that ICSI procedures might cause oocyte damage. Therefore, the choice of fertilization method should be based on semen quality. A randomized controlled trial should be performed to confirm our findings.

Intracytoplasmic sperm injection vs. conventional in vitro fertilization in patients with non-male factor infertility

OBJECTIVE

To compare the cumulative live birth rates (CLBRs) and cost effectiveness of intracytoplasmic sperm injection (ICSI) and conventional in vitro fertilization (cIVF) for non-male factor infertility.

DESIGN

A retrospective cohort study.

SETTING

Society for Assisted Reproductive Technology clinics.

PATIENT(S)

A total of 46,967 patients with non-male factor infertility with the first autologous oocyte retrieval cycle between January 2014 and December 2015.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The primary outcomes were CLBR, defined as up to 1 live birth from an autologous retrieval cycle between 2014 and 2015, and linked fresh and frozen embryo transfers through 2016. The secondary outcomes included miscarriage rate, 2 pronuclei per oocyte retrieved, and the total number of transferred and frozen embryos. Analyses were performed on subsamples with and without preimplantation genetic testing for aneuploidy (PGT-A). A cost analysis was performed to determine the costs accrued by ICSI.

RESULT(S)

Among cycles without PGT-A in patients with non-male factor infertility, the CLBR was 60.9% for ICSI cycles vs. 64.3% for cIVF cycles, a difference that was not significantly different after adjustment for covariates (adjusted risk ratio, 0.99; 95% confidence interval, 0.99-1.00). With PGT-A, no difference in CLBR was found between ICSI and cIVF cases after adjustment (64.7% vs. 69.0%, respectively; adjusted risk ratio, 0.97; 95% confidence interval, 0.93-1.01). The patients were charged an estimated additional amount of $37,476,000 for ICSI without genetic testing and an additional amount of $7,213,500 for ICSI with PGT-A over 2 years by Society for Assisted Reproductive Technology clinics.

CONCLUSION(S)

In patients with non-male factor infertility, ICSI did not improve CLBR. Given the additional cost and the lack of CLBR benefit, our data show that the routine use of ICSI in patients with non-male factor infertility is not warranted.

Effects of donor sperm on perinatal and neonatal outcomes resulting from in vitro fertilization-intracytoplasmic sperm injection and embryo transfer cycles: a retrospective cohort study

Background

The impact of donor sperm on pregnancy outcomes is controversial. The aim of this study was to investigate whether donor sperm in in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) treatment could reduce the rate of live births or increase the incidence of adverse pregnancy outcomes and birth defects in neonates.

Methods

This single-centre, retrospective cohort study included 1,559 patients with infertility who received donor sperm at our hospital from 2015 to 2019. All the patients received fresh embryos and underwent first-cycle transfer. After propensity score matching, 4,677 controls who received their partners’ sperm were matched at 1:3. Clinical pregnancy, perinatal, and neonatal outcomes were compared between the donor sperm and partner sperm groups.

Results

The embryo development was better in the donor sperm group than in the partner sperm group. The high-quality embryo and available embryo rates were significantly higher in the donor sperm group (P<0.05 for both groups). The rate of high-quality embryos transferred from the donor sperm group was higher than that from the partner sperm group (P<0.05). The clinical pregnancy (62.99% vs. 59.65%; P=0.02) and live birth (54.65% vs. 51.59%; P=0.036) rates were higher in the donor sperm group. After adjusting for confounding factors, no significant difference in live birth rates was observed between the two groups (adjusted P=0.057). The low birthweight (18.21% vs. 21.39%; P=0.023) and small for gestational age (SGA) (7.60% vs. 11.97%; P<0.001) rates were lower in the donor sperm group. To exclude the effect of multiple pregnancies, we evaluated neonatal outcomes of singleton pregnancies. No significant differences were noted in preterm and very preterm birth, SGA, mean birthweight, high birthweight, and low birth weight (LBW) and very low birth weight (VLBW) rates (P>0.05 for both groups). Further, no significant between group differences were observed in the ectopic pregnancy rate, early and late spontaneous abortion rates, gestational age, rate of large for gestational age (LGA), and neonatal defects.

Conclusions

Compared with partner sperm, donor sperm did not reduce live birth rate and did not increase neonatal LBW or low birth defects.

The impact of blastomere loss on pregnancy and neonatal outcomes of vitrified-warmed Day3 embryos in single embryo transfer cycles

BACKGROUND

Blastomere loss is a common phenomenon that occurs following cryopreservation. To date, studies have drawn conflicting conclusions regarding the impact of blastomere loss on pregnancy outcomes. Besides, limited information is available concerning the neonatal safety of embryos with blastomere loss. In the present study, we aimed to investigate the impact of blastomere loss on pregnancy and neonatal outcomes of vitrified/warmed Day3 cleavage-stage embryos in single embryo transfer cycles.

METHODS

This retrospective cohort study included all vitrified/warmed D3 cleavage-stage single frozen-thawed embryo transfer (FET) cycles between April 2015 and February 2021. We compared pregnancy and subsequent neonatal outcomes between the intact embryos group and the blastomere loss group in single FET cycles.

RESULTS

A total of 6287 single FET cycles were included in the study, in which 5873 cycles were classified into the intact embryo group and 414 cycles were classified into the blastomere loss group. The outcomes of the blastomere loss group were significantly inferior to those of the intact embryo group, in terms of implantation/biochemical pregnancy/clinical pregnancy/ongoing pregnancy rate and live birth rate per embryo transfer cycle/per clinical pregnancy. Further binary logistic regression confirmed that blastomere loss was negatively associated with live birth. Moreover, the blastomere loss group presented with an elevated early miscarriage rate. The neonatal conditions were broadly similar between the two groups. Additionally, multiple binary logistic regression analysis demonstrated that primary infertility and intracytoplasmic sperm injection (ICSI) were common influencing factors of blastomere loss (aOR 1.447, 95% CI 1.038-2.019, P = 0.029; aOR: 1.388, 95% CI: 1.044-51.846, P = 0.024).

CONCLUSIONS

The transfer of vitrified/warmed D3 embryos with blastomere loss is related to impaired embryo developmental potentials and reduced probabilities of conception. Moreover, even if the embryos with blastomere loss have implanted and reached clinical pregnancies, they present with a lower possibility of developing to live birth owing to a higher early miscarriage rate. However, once the embryos with blastomere loss result in a live birth, no adverse neonatal outcomes are observed. Primary infertility and ICSI were found to be risk factors for blastomere loss.

Repro-protective role of royal jelly in phenylhydrazine-induced hemolytic anemia in male mice: Histopathological, embryological, and biochemical evidence

To estimate the repro-protective effect of royal jelly (RJ) on phenylhydrazine (PHZ)-induced anemia's detrimental effects, 24 mature mice were divided into control group (0.10 mL normal saline; intra-peritoneally), RJ group (100 mg/kg/day; orally), experimental anemia (EA) group that received only PHZ (6 mg/100 g/48 h; intra-peritoneally), and RJ + EA (according to the previous prescription) group. After 35 days, testicular histoarchitecture, RNA damage in germinal cells, sperm characteristics, testicular total anti-oxidant capacity and malondialdehyde as well as serum testosterone levels, pre-implantation embryo development and cyclin D1 and c-myc mRNA levels at two-cell, morula and blastocyst stages were analyzed. Spermatogenesis indices were ameliorated following RJ co-administration. Moreover, RJ co-treatment reduced germinal cells RNA damage, improved sperm characteristics, boosted pre-implantation embryo development and restored androgenesis, and oxidant/anti-oxidant status. Co-administration of RJ also decreased mRNA levels of cyclin D1 and up-regulated those of c-myc in two-cell embryos, morulas and blastocysts. The findings suggest that RJ can play a repro-protective role in PHZ-induced anemia in mice through anti-oxidant defense system reinforcement and androgenesis restoration as well as cyclin D1 and c-myc expressions regulation.

Does Choosing Microfluidics for Sperm Sorting Offer an Advantage to Improve Clinical Pregnancies in Donor Egg Recipients?

Background:

Microfluidics (MF), an advanced sperm sorting technology results in the extraction of spermatozoa with higher DNA integrity and lower DNA damage compared to existing conventional sperm sorting methods.

Aims:

The aim of the present study is to assess the efficiency of MF and to isolate the best spermatozoa for intracytoplasmic sperm injection (ICSI) over the density gradient (DG) technique.

Study Setting and Design:

We recruited couples who choose the oocyte donation programme for this study to eliminate confounding factors associated with oocyte quality.

Materials and Methods:

Sperm was processed by MF (n = 180) and DG (n = 151). ICSI was performed and positive pregnancy, miscarriage and clinical pregnancy rates were compared.

Statistical Analysis:

All variables were analysed using Graph Pad Prism 5. The unpaired two-tailed t-test was used to assess the significance. A value of P < 0.05 was considered statistically significant.

Results:

There was no significant difference in pregnancy rates between the groups. However, a clear demarcation is seen in terms of clinical pregnancy rates, where the DG group achieved higher clinical pregnancies (91.7%) compared to the MF group (80.7%). Further, we compared miscarriage rates and biochemical pregnancies, and found a significantly higher miscarriage and biochemical pregnancy rate in the MF group (14.5% and 4%, respectively) compared to the DG group (6% and 1%, respectively).

Conclusions:

Based on the available literature, we anticipated a higher clinical pregnancy rate with MF compared with conventional processing. Our results show MF does not have any add-on positive effect on clinical pregnancy rate.

GnRH-agonist pretreatment in hormone replacement therapy improves pregnancy outcomes in women with male-factor infertility

OBJECTIVE

This study aimed to examine the efficacy of HRT with gonadotropin-releasing hormone agonist (GnRH-a) pre-treatment in women with male-factor infertility who underwent a frozen embryo transfer (FET) programme.

DESIGN

Between January 2016 and October 2020, 2733 women with male-factor infertility who underwent the HRT protocol as the endometrial preparation method were enrolled at two Reproductive Medicine Centres. Patients were divided into two groups based on whether they had GnRH-a pre-treatment before HRTs: the GnRHa-HRT group and the HRT group. The inverse probability of treatment weighting (IPTW) method was conducted to balance patient baseline characteristics between treatment cohorts to reduce selection bias. The live birth rate was considered regarded as the primary pregnancy outcome.

RESULTS

Multivariate logistic regression adjusted for confounding factors, the GnRHa-HRT group showed a notably higher rate of live birth (OR 2.154, 95% CI 1.636~2.835, P<0.001) when compared to the HRT group. Additionally, the rate of miscarriage was significantly lower in the GnRHa-HRT group. The GnRHa-HRT group had significantly higher rates of biochemical pregnancy, clinical pregnancy, multiple pregnancy, and term birth.

CONCLUSION

The endometrial preparation protocol of HRT with GnRH-a pre-treatment could obviously increase the live birth rate for women with male-factor infertility undergoing the FET programme.

Usefulness of expanding the indications of early rescue intracytoplasmic sperm injection

Purpose

Early rescue intracytoplasmic sperm injection (ICSI) is often performed in cases in which not even a single oocyte has extruded a second polar body 6 h after insemination. We evaluated the usefulness of expanding the indications of early rescue ICSI to cases in which <80% of oocytes have extruded second polar bodies 6 h after insemination.

Methods

Early rescue ICSI was performed on oocytes that were denuded 2.5 h post‐insemination and whose extrusion of the second polar bodies had been examined 6 h post‐insemination with a PolScope.

Results

In vitro fertilization was performed on 24 496 oocytes of 4944 cycles, and 1438 cycles had <80% rate of the second polar body extrusion. Rescue ICSI was performed on 3933 oocytes. Three pronuclei (3PN) incidence of rescue ICSI was 3.0% in oocytes with ≥50% rate of the second polar body extrusion. With respect to the second polar body extrusion rate, no differences were observed in normal fertilization, blastocyst development, implantation, miscarriage, or live birth rates for rescue ICSI.

Conclusion

By expanding the indications of early rescue ICSI using the PolScope to cases in which <80% of oocytes have extruded the second polar bodies, many fertilized oocytes can be obtained without considerably increasing the 3PN rate.

Is there still a role for a cleavage-stage embryo transfer?

Objective

To determine whether pregnancy outcomes are poor or futile when an intended day 5 transfer is converted to a cleavage-stage transfer because of poor embryo development or a lower number of embryos.

Design

Retrospective cohort study.

Setting

Academic medical center.

Patient(s)

Women with a limited number of embryos, defined as ≤6 two pronuclear embryos, after in vitro fertilization.

Intervention(s)

Patients who had a cleavage-stage transfer were age matched with patients who had a day 5 transfer.

Main Outcome Measure(s)

Live birth rate.

Result(s)

A total of 146 women were included in the study with 73 women in each group. Cleavage-stage transfer was associated with significantly lower implantation and clinical pregnancy rates compared with those of day 5 transfer. Although the live birth rate of the cleavage-stage transfer group was lower than that of the day 5 transfer group (25% vs. 40%, respectively), the cleavage-stage transfer still resulted in a live birth rate of 25%. A subanalysis comparing women who did and did not achieve live birth after cleavage-stage transfer demonstrated a live birth rate of 27% when at least one grade A embryo was transferred vs. 17% when a lesser quality embryo (grade B or C) was transferred.

Conclusion(s)

As expected, the live birth rate after cleavage-stage transfer was lower than that after day 5 transfer. However, the live birth rate of cleavage-stage transfer still fell into acceptable practice, >5%, for patients who were otherwise at very high risk of having no day 5 embryo transfer. Extended culture may not be necessary for all patients.

Sperm Selection and Embryo Development: A Comparison of the Density Gradient Centrifugation and Microfluidic Chip Sperm Preparation Methods in Patients with Astheno-Teratozoospermia

In recent years, microfluidic chip-based sperm sorting has emerged as an alternative tool to centrifugation-based conventional techniques for in vitro fertilization. This prospective study aims to compare the effects of density gradient centrifugation and microfluidic chip sperm preparation methods on embryo development in patient populations with astheno-teratozoospermia. In the study, the semen samples of the patients were divided into two groups for preparation with either the microfluidic or density gradient methods. Selected spermatozoa were then used to fertilize mature sibling oocytes and the semen parameters and embryo development on days 3 and 5 were assessed. While the density gradient group was associated with a higher sperm concentration, motility (progressive and total) was significantly higher in the microfluidic chip group. No significant differences were observed in the fertilization rates or grade 1 (G1) and grade 2 (G2) proportions of the third-day embryos. Furthermore, while the proportions of the poor, fair and good blastocysts on day 5 did not differ significantly, excellent blastocysts (indicating high-quality embryos) were observed in a significantly higher proportion of the microfluidic chip group. When compared to the classical density gradient method, the microfluidic chip sperm preparation yielded sperm with higher motility and higher quality blastocysts at day 5; in patients with astheno-teratozoospermia.

Molecular Drivers of Developmental Arrest in the Human Preimplantation Embryo: A Systematic Review and Critical Analysis Leading to Mapping Future Research

Developmental arrest of the preimplantation embryo is a multifactorial condition, characterized by lack of cellular division for at least 24 hours, hindering the in vitro fertilization cycle outcome. This systematic review aims to present the molecular drivers of developmental arrest, focusing on embryonic and parental factors. A systematic search in PubMed/Medline, Embase and Cochrane-Central-Database was performed in January 2021. A total of 76 studies were included. The identified embryonic factors associated with arrest included gene variations, mitochondrial DNA copy number, methylation patterns, chromosomal abnormalities, metabolic profile and morphological features. Parental factors included, gene variation, protein expression levels and infertility etiology. A valuable conclusion emerging through critical analysis indicated that genetic origins of developmental arrest analyzed from the perspective of parental infertility etiology and the embryo itself, share common ground. This is a unique and long-overdue contribution to literature that for the first time presents an all-inclusive methodological report on the molecular drivers leading to preimplantation embryos’ arrested development. The variety and heterogeneity of developmental arrest drivers, along with their inevitable intertwining relationships does not allow for prioritization on the factors playing a more definitive role in arrested development. This systematic review provides the basis for further research in the field.

Intracytoplasmic sperm injection is not superior to conventional IVF in couples with non-male factor infertility and preimplantation genetic testing for aneuploidies (PGT-A)

STUDY QUESTION

Does the insemination method impact the euploidy outcome in couples with non-male factor infertility?

SUMMARY ANSWER

Conventional IVF can be applied in cycles with preimplantation genetic testing for aneuploidies (PGT-A), as both IVF and ICSI generate equal numbers of euploid blastocysts.

WHAT IS KNOWN ALREADY

Ever since its introduction, the popularity of ICSI has increased tremendously, even in couples with non-male factor infertility. The use of conventional IVF is a contraindication for couples undergoing PGT to ensure monospermic fertilisation and to eliminate potential paternal contamination from extraneous sperm attached to the zona pellucida. Despite this, it has recently been shown that sperm DNA fails to amplify under the conditions used for trophectoderm biopsy samples.

STUDY DESIGN, SIZE, DURATION

This single-centre prospective pilot study included 30 couples between November 2018 and April 2019.

PARTICIPANTS/MATERIALS, SETTING, METHOD

Arab couples, with a female age between 18-40 years, body mass index ≤30 kg/m2, at least 10 cumulus oocyte complexes (COCs) following oocyte retrieval (OR) and normal semen concentration and motility (WHO) in the fresh ejaculate on the day of OR, were eligible for the study. Half of the sibling oocytes were assigned to conventional IVF, and the other half were assigned to ICSI. All embryos were cultured in a time-lapse imaging system in Global Total LP media. Blastocysts were subjected to trophectoderm biopsy on Day 5, 6 or 7 and next-generation sequencing (NGS) to determine blastocyst ploidy status. The primary objective was to determine the euploid rate in blastocysts from sibling oocytes.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 568 COCs were randomly allocated between IVF (n = 283; 9.4 ± 4.0) and ICSI (n = 285; 9.5 ± 4.1). While the incidence of normal fertilisation per cycle (6.1 ± 3.8 (64.0%) vs 6.3 ± 3.5 (65.4%); P = 0.609) was distributed equally between IVF and ICSI, the degeneration rate (0.1 ± 0.3 vs 0.7 ± 0.8; P = 0.0003) was significantly higher after ICSI and the incidence of abnormal fertilisation (≥3 pronuclei) was significantly higher after IVF (0.9 ± 1.2 vs 0.2 ± 0.4; P = 0.005). For all fertilised oocytes, there were no differences in the number of good-quality embryos on Day 3 (74% vs 78%; P = 0.467), nor in the blastulation rate on Day 5 (80.4% vs 70.8%; P = 0.076). The total number of blastocysts biopsied per cycle on Days 5, 6 and 7 was not significantly different between IVF or ICSI (4.0 ± 2.8 vs 3.9 ± 2.5; P = 0.774). With euploid rates of 49.8 and 44.1% (P = 0.755; OR: 1.05664 [0.75188-1.48494), respectively, there was no significant difference identified between IVF and ICSI (2.0 ± 1.8 vs 1.9 ± 1.7; P = 0.808) and all couples had at least one euploid blastocyst available for transfer. When considering only euploid blastocysts, the male/female ratio was 61/39 in IVF and 43/57 in ICSI (P = 0.063).

LIMITATIONS, REASON FOR CAUTION

This is a pilot study with a limited patient population of 30 couples (and 568 COCs) with a normal ovarian response. The results of our study should not be extrapolated to other patient populations.

WIDER IMPLICATIONS OF THE FINDINGS

It is safe to apply conventional IVF in couples with non-male factor infertility undergoing PGT-A.

STUDY FUNDING/COMPETING INTEREST(S)

No funding was obtained. There are no competing interests.

TRIAL REGISTRATION NUMBER

NCT03708991.

Influence of sperm morphology on pregnancy outcome and offspring in in vitro fertilization and intracytoplasmic sperm injection: a matched case-control study

Sperm morphology was once believed as one of the most predictive indicators of pregnancy outcome in assisted reproductive technology (ART). However, the impact of teratozoospermia on in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) outcomes and its offspring remains inconclusive. In order to evaluate the influence of teratozoospermia on pregnancy outcome and newborn status after IVF and ICSI, a retrospective study was conducted. This was a matched case-control study that included 2202 IVF cycles and 2574 ICSI cycles and was conducted at the Reproductive and Genetic Hospital of CITIC-Xiangya in Changsha, China, from June 2013 to June 2018. Patients were divided into two groups based on sperm morphology: teratozoospermia and normal sperm group. The pregnancy outcome and newborn outcome were analyzed. The results indicated that couples with teratozoospermia had a significantly lower optimal embryo rate compared to those with normal sperm morphology in IVF (P = 0.007), while there were no statistically significant differences between the two groups in terms of the fertilization rate, cleavage rate, implantation rate, and pregnancy rate (all P > 0.05). Additionally, teratozoospermia was associated with lower infant birth weight in multiple births after IVF. With regard to ICSI, there was no significant difference in both pregnancy outcome and newborn outcome between the teratozoospermia and normal groups (both P > 0.05). Furthermore, no increase in the risk of birth defects occurred in the teratozoospermia group after IVF/ICSI. Consequently, we believe that teratozoospermia has limited predictive value for pregnancy outcomes in IVF/ICSI, and has little impact on the resulting offspring if multiple pregnancy is avoided.

The Development of Nomograms to Predict Blastulation Rate Following Cycles of In Vitro Fertilization in Patients With Tubal Factor Infertility, Polycystic Ovary Syndrome, or Endometriosis

It is well known that the transfer of embryos at the blastocyst stage is superior to the transfer of embryos at the cleavage stage in many respects. However, the rate of blastocyst formation remains low in clinical practice. To reduce the possibility of wasting embryos and to accurately predict the possibility of blastocyst formation, we constructed a nomogram based on range of clinical characteristics to predict blastocyst formation rates in patients with different types of infertility. We divided patients into three groups based on female etiology: a tubal factor group, a polycystic ovary syndrome group, and an endometriosis group. Multiple logistic regression was used to analyze the relationship between patient characteristics and blastocyst formation. Each group of patients was divided into a training set and a validation set. The training set was used to construct the nomogram, while the validation set was used to test the performance of the model by using discrimination and calibration. The area under the curve (AUC) for the three groups indicated that the models performed fairly and that calibration was acceptable in each model.

Current Insights and Latest Updates in Sperm Motility and Associated Applications in Assisted Reproduction

Spermatozoon is a motile cell with a special ability to travel through the woman’s reproductive tract and fertilize an oocyte. To reach and penetrate the oocyte, spermatozoa should possess progressive motility. Therefore, motility is an important parameter during both natural and assisted conception. The global trend of progressive reduction in the number and motility of healthy spermatozoa in the ejaculate is associated with increased risk of infertility. Therefore, developing approaches for maintaining or enhancing human sperm motility has been an important area of investigation. In this review we discuss the physiology of sperm, molecular pathways regulating sperm motility, risk factors affecting sperm motility, and the role of sperm motility in fertility outcomes. In addition, we discuss various pharmacological agents and biomolecules that can enhance sperm motility in vitro and in vivo conditions to improve assisted reproductive technology (ART) outcomes. This article opens dialogs to help toxicologists, clinicians, andrologists, and embryologists in understanding the mechanism of factors influencing sperm motility and various management strategies to improve treatment outcomes.

Incidences and risk factors of moderate-to-severe ovarian hyperstimulation syndrome and severe hemoperitoneum in 1,435,108 oocyte retrievals

RESEARCH QUESTION

What are the risk factors affecting the incidences of moderate-to-severe ovarian hyperstimulation syndrome (OHSS) and severe hemoperitoneum in assisted reproductive technology (ART) treatment cycles?

DESIGN

A retrospective cohort study was conducted on 1,435,108 oocyte retrieval cycles among Japanese ART registry data between 2007 and 2015. The study included 11,378 cycles with moderate-to-severe OHSS, 1182 cycles with severe hemoperitoneum, including 27 cycles with both conditions, and 1,422,575 cycles without moderate-to-severe OHSS and severe hemoperitoneum.

RESULTS

The incidences of moderate-to-severe OHSS and severe hemoperitoneum were 0.79% and 0.08%, respectively, and decreased by 0.57-fold and 0.29-fold from 2007 to 2015, respectively. In cycles with OHSS and cycles with hemoperitoneum women were younger (odds ratios [OR] 0.91 and 0.95, respectively) and had more retrieved oocytes (OR 1.09 and 1.01, respectively) compared with cycles without both complications. The use of a gonadotrophin-releasing hormone (GnRH) agonist protocol for ovarian stimulation was the highest risk factor in cycles with OHSS and hemoperitoneum (OR 1.83 and 1.24, respectively), followed by GnRH antagonist protocol (reference), gonadotrophin with or without oral medicine (OR 0.45 and 0.56, respectively) and natural or oral medicine (OR 0.02 and 0.19, respectively). In fresh embryo transfer, clinical pregnancy was associated with an increased risk of OHSS and hemoperitoneum (OR 1.19 and 2.34, respectively).

CONCLUSIONS

The highest risk factors affecting OHSS and hemoperitoneum were the use of a GnRH agonist protocol and clinical pregnancy following fresh embryo transfer. The incidences of OHSS and hemoperitoneum have decreased yearly with a reduction of GnRH agonist use and fresh embryo transfer.

Microinjection induces changes in the transcriptome of bovine oocytes

Gene knockdown techniques are widely used to examine the function of specific genes or proteins. While a variety of techniques are available, a technique commonly used on mammalian oocytes is mRNA knockdown by microinjection of small interfering RNA (siRNA), with non-specific siRNA injection used as a technical control. Here, we investigate whether and how the microinjection procedure itself affects the transcriptome of bovine oocytes. Injection of non-specific siRNA resulted in differential expression of 119 transcripts, of which 76 were down-regulated. Gene ontology analysis revealed that the differentially regulated genes were enriched in the biological processes of ATP synthesis, molecular transport and regulation of protein polyubiquitination. This study establishes a background effect of the microinjection procedure that should be borne in mind by those using microinjection to manipulate gene expression in oocytes.

Reproductive outcomes with donor sperm in couples with severe male-factor infertility after intracytoplasmic sperm injection failures

PURPOSE

To evaluate reproductive outcomes of artificial insemination and IVF with donor sperm (AID or IVF-D) for male-factor couples with a history of unsuccessful ICSI attempt.

METHODS

This retrospective cohort includes couples with severe male-factor infertility who failed ICSI treatment, and subsequently underwent semen donation treatment. We report the following outcomes: (1) live birth rates in AID and IVF-D treatment for couples with severe male infertility factors and prior ICSI failures; (2) paternal impact on embryo development of the same oocyte cohort; (3) prognostic factors in obtaining a live birth with donor semen.

RESULTS

Of 92 women with failed ICSI cycles (26 with multiple attempts), 45 couples underwent AID treatment. Live birth rate per cycle of AID was 18.9%. Fifty-three patients underwent IVF-D including 6 couples who previously did not conceive with AID. Embryological outcomes including fertilization, viable cleavage embryos, and blastocyst formation rates were significantly lower in ICSI cycles with partner sperm compared with IVF-D (P < 0.01). Logistic regression analysis showed that female age and the severity of spermatogenetic disorder are prognostic factors in obtaining a live birth with donated sperm.

CONCLUSION

Couples with severe male infertility factor (azoospermia or extreme oligoasthenospermia) and a history of unsuccessful ICSI cycles benefit from treating with donor sperm. ICSI fertilization, embryo viability, and progression of the embryo to the blastocyst stage are significantly deteriorated by semen parameters. The prognostic factors identified may help couples plan their treatment and prepare for their parenthood journey.

Is intracytoplasmic sperm (ICSI) better than traditional in vitro fertilization (IVF): confirmation of higher blastocyst rates per oocyte using a split insemination design

PURPOSE

To explore the effects of traditional vs. intracytoplasmic sperm injection (ICSI) insemination method on the outcome of high-quality blastocyst development in a split sibling oocyte cohort.

METHODS

In this retrospective cohort study, we analyzed 62 ICSI/IVF split cycles. Sibling oocytes were randomly assigned to ICSI or IVF insemination. Two hundred thirty-four ICSI-only cycles and 152 IVF-only cycles were also analyzed for comparison. Blastocysts were graded by Gardner's embryo grading and were considered a high-quality blastocyst if 3BB or better (Gardner 1999).

RESULTS

In the ICSI/IVF split group, (1) ICSI oocytes had a higher fertilization rate per oocyte allocated (73% vs 62%, p < 0.001), (2) more high-quality day 2 embryos (69% vs 55%, p < 0.005), (3) ICSI oocytes had a lower blastulation rate per 2PN (46% vs 54%, p < 0.05), but a higher blastulation rate when calculated per oocyte allocated (40% vs 32%, p < 0.05). The ICSI-only group had a lower fertilization rate (65% vs 70%, p < 0.001) but more high-quality day 2 embryos in comparison to the IVF-only group (68% vs 64%, p < .05). The total high-quality blastulation rate was higher for the IVF-only group per 2PN (49% vs 43%, p < 0.05) and per oocyte retrieved (34% vs 28%, p < 0.05).

CONCLUSIONS

This distinctive IVF/ICSI sibling oocyte split design demonstrated a higher-quality blastulation rate in the IVF group compared to the ICSI group when calculated per 2PN, but not per oocyte allocated to each insemination procedure.

Intracytoplasmic sperm injection (ICSI) versus conventional in vitro fertilisation (IVF) in couples with non-severe male infertility (NSMI-ICSI): protocol for a multicentre randomised controlled trial

INTRODUCTION

Intracytoplasmic sperm injection (ICSI), originally introduced as add-on to in vitro fertilisation (IVF) for couples with severe male infertility, is in current clinical practice also used in couples with mild male or even unexplained infertility. However, ICSI has involved unresolved concerns regarding the selection and damage to gametes and the health conditions of the offspring, and it is also labour intensive and therefore more expensive than conventional IVF. High-quality well-powered randomised clinical trials (RCTs) comparing ICSI and IVF are lacking.

METHODS AND ANALYSIS

We propose a multicentre, open-label RCT in 10 reproductive medical centres across China. We will study couples with non-severe male infertility (defined as a semen concentrate 5-15×106/mL or sperm with a progressive motility 10%-32%) scheduled for their first or second ICSI or IVF cycle, as low fertility rate after fertilisation are more frequent in this population, which could lead to controversy about ICSI or conventional IVF for fertilisation. On the day of oocyte retrieval, eligible participants are after informed consent be randomised to undergo either ICSI or conventional IVF in a 1:1 treatment ratio. Other standard assisted reproductive treatments are similar and parallel between two groups. Our primary outcome is ongoing pregnancy leading to live birth after the first cycle with embryo transfer. To demonstrate or refute a difference of 7% between ICSI and conventional IVF, we need to include 2346 women (1173 in each intervention arm). In addition, we will follow-up neonatal outcomes after delivery to identify the influence of ICSI on offspring.

ETHICS AND DISSEMINATION

Ethical approval was obtained from Peking University Third Hospital medical science research ethics committee. The findings will be disseminated to the public through conference presentations and peer-reviewed scientific journals.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov registry (NCT03298633).

The effect of paternal age on semen quality and fertilization outcome in men with normal sperm DNA compaction, reactive oxygen species, and total antioxidant capacity levels

OBJECTIVE

Studies showed a decrease of the semen analysis parameters and an increase in the average age of first-time fathers over the past several decades. The aim of the present study was to assess the influence of paternal age on semen quality and fertilization outcomes in men with normal sperm DNA fragmentation and chromatin maturation index (DFI and CMI), reactive oxygen species (ROS), and total antioxidant capacity (TAC) levels.

MATERIAL AND METHODS

The study was performed on 70 men with their wife's age ≤38 years and normal sperm DFI, CMI, ROS, and TAC levels. None of the couples had a history of genital inflammation, chronic diseases, endocrine abnormality, chromosomal aberrations, Y chromosome microdeletion, azoospermia, and leukocytospermia. These men were separated into 2 groups according to their age (group A: age <45 years and group B: age ≥45 years). Semen analysis and fertilization outcome after using the intracytoplasmic sperm injection were assessed in both groups.

RESULT

Sperm concentration showed a significant reduction in group B (p=0.04). Although semen volume, sperm normal morphology, and progressive motility were decreased in group B, the reduction was not significant when compared with group A (p=0.09, p=0.47, and p=0.77, respectively). In addition, the differences of embryo quality with grades A, B, and C and 8-cell embryo formation were not statistically significant between the 2 groups.

CONCLUSION

These results demonstrated that in men with normal sperm DFI, CMI, ROS, and TAC levels, there were no significant changes in semen parameters and fertilization outcomes with an increasing age.

Fertility and Neonatal Outcomes of Freeze-All vs. Fresh Embryo Transfer in Women With Advanced Endometriosis

Background: Eutopic endometrium from women with endometriosis has functional changes in several aspects, which may largely account for the decrease in the quality of endometrial receptivity. It is of utmost importance to know whether freeze-all strategy can restore optimal receptivity in endometriotic women leading to the better ART outcomes. Methods: Retrospective study involved patients with advanced endometriosis undergoing first embryo transfer cycles during the period from March 2006 to March 2017 at a tertiary care center. After propensity score matching, there were 506 women in the freeze-all group and 255 women in fresh group. Our main outcomes included the rates of implantation, clinical pregnancy, and live birth. Subgroup analyses were performed after stratification by the number of oocytes retrieved and fertilization method. Neonatal outcomes included gestational age and birth weight z-score for singletons and multiple births. Results: In our matched cohort, the implantation, clinical pregnancy and live birth rates were statistically significantly higher in the freeze-all group compared with fresh transfer groups (34.4 vs. 25.5%, 51.8 vs. 38.8%, and 45.3 vs. 31.8%, all P < 0.001, respectively). A more beneficial effect of freeze-all cycles was found in patients who got more than 15 oocytes. Additionally, when ICSI insemination techniques were used to achieve fertilization, the advantage of freeze-all strategy was not obvious. Assessment of 382 babies showed no statistically significant difference in the mode of delivery, sex of live-born, gestational age, unadjusted median birth weight, and z-score between two study groups. Conclusion: Freeze-all strategy is an attractive option to improve the outcomes of ART for women with advanced endometriosis.

Potential of testicular sperm to support embryonic development to the blastocyst stage is comparable to that of ejaculated sperm

PURPOSE

Recent studies have shown that improved clinical outcomes can be achieved by transferring blastocysts rather than cleavage-stage embryos. However, blastocyst transfer is not performed in all patients. The aim of this study was to compare clinical outcomes of intracytoplasmic sperm injection (ICSI) cycles using testicular sperm (TE) with those of ICSI cycles using ejaculated sperm (EJ).

METHODS

ICSI was performed using EJ in 141 cycles and TE in 37 cycles. Embryos were cultured for 5 days. The quality of embryos was assessed on days 3 and 5 before embryo transfer.

RESULTS

Fertilization rate was 77.3% in the EJ group and 69.6% in the TE group (p < 0.05). The good-quality embryos on day 3 and 5 were not different between the EJ and TE groups. Embryos did not develop to blastocyst stage in 7 cycles of the EJ group (5.0%) and 2 cycles of the TE group (5.4%). There were no significant differences in blastocyst formation and blastocyst quality (46.1% vs. 47.5% and 5.7% vs 5.8%, respectively) on day 5 between both groups. Embryos were transferred in all cycles. Implantation (22.8 vs. 24.7%), clinical pregnancy (44.7 vs. 43.2%), miscarriage (21.7 vs. 33.3%), and delivery (76.5 vs. 66.7%) did not differ between EJ group and TE group. Clinical outcomes of ICSI were not different between the EJ and TE groups.

CONCLUSIONS

In conclusion, the potential of testicular sperm supporting embryonic development to blastocysts is comparable to that of ejaculated sperm. Therefore, this study suggests that blastocyst transfer can be a very useful assisted reproductive technique in the ICSI cycles that require the use of testicular sperm, and the clinical outcomes of the cycles are comparable to those of ICSI cycles using ejaculated sperm.

Influence of the insemination method on the outcomes of elective blastocyst culture

Objective

The aim of this study was to explore the effects of the insemination method on the outcomes of elective blastocyst culture.

Methods

We retrospectively analyzed the outcomes of elective blastocyst culture performed between January 2011 and December 2014.

Results

There were 2,003 cycles of conventional in vitro fertilization (IVF) and 336 cycles of intracytoplasmic sperm injection (ICSI), including 25,652 and 4,164 embryos that underwent sequential blastocyst culture, respectively. No significant differences were found in the female patients' age, basal follicle-stimulating hormone level, basal luteinizing hormone level, body mass index, number of oocytes, maturity rate, fertilization rate, or good-quality embryo rate. However, the blastocyst formation rate and embryo utilization rate were significantly higher in the conventional IVF group than in the ICSI group (54.70% vs. 50.94% and 51.09% vs. 47.65%, respectively, p<0.05). The implantation/pregnancy rate (IVF, 50.93%; ICSI, 55.10%), miscarriage rate (IVF, 12.57%; ICSI, 16.29%), and live birth rate (IVF, 42.12%; ICSI, 44.08%) were similar (p>0.05). No cycles were canceled due to the formation of no usable blastocysts.

Conclusion

Although the fertilization method had no effect on clinical outcomes, the blastocyst formation rate and embryo utilization rate in the ICSI group were significantly lower than those observed in the conventional IVF group. Therefore, more care should be taken when choosing to perform blastocyst culture in ICSI patients.

Clinical outcomes after IVF or ICSI using human blastocysts derived from oocytes containing aggregates of smooth endoplasmic reticulum

In this study the clinical and neo-natal outcomes after transfer of blastocysts derived from oocytes containing aggregates of smooth endoplasmic reticulum (SER) were compared between IVF and intracytoplasmic sperm injection (ICSI) cycles. Clinical and neo-natal outcomes of blastocysts in cycles with at least one SER metaphase II oocyte (SER + MII; SER + cycles) did not significantly differ between the two insemination methods. When SER + MII were cultured to day 5/6, fertilization, embryo cleavage and blastocyst rates were not significantly different between IVF and ICSI cycles. In vitrified-warmed blastocyst transfer cycles, the clinical pregnancy rates from SER + MII in IVF and ICSI did not significantly differ. In this study, 52 blastocysts (27 IVF and 25 ICSI) derived from SER + MII were transferred, yielding 15 newborns (5 IVF and 10 ICSI) and no malformations. Moreover, 300 blastocysts (175 IVF and 125 ICSI) derived from SER-MII were transferred, yielding 55 newborns (24 IVF and 31 ICSI cycles). Thus, blastocysts derived from SER + cycles exhibited an acceptable ongoing pregnancy rate after IVF (n = 125) or ICSI (n = 117) cycles. In conclusion, blastocysts from SER + MII in both IVF and ICSI cycles yield adequate ongoing pregnancy rates with neo-natal outcomes that do not differ from SER-MII.

Sperm quality and paternal age: effect on blastocyst formation and pregnancy rates

BACKGROUND

Several studies suggest a decrease in sperm quality in men in the last decades. Therefore, the aim of this work was to assess the influence of male factors (sperm quality and paternal age) on the outcomes of conventional in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI).

METHODS

This retrospective study included all couples who underwent IVF or ICSI at Montpellier University Hospital, France, between 1 January 2010 and 31 December 2015. Exclusion criteria were cycles using surgically retrieved sperm or frozen sperm, with pre-implantation genetic diagnosis or using frozen oocytes. The primary outcomes were the blastulation rate (number of blastocysts obtained at day 5 or day 6/number of embryos in prolonged culture at day 3) and the clinical pregnancy rate. The secondary outcomes were the fertilization and early miscarriage rates.

RESULTS

In total, 859 IVF and 1632 ICSI cycles were included in this study. The fertilization rate after ICSI was affected by oligospermia. Moreover, in ICSI, severe oligospermia (lower than 0.2 million/ml) led to a reduction of the blastulation rate. Reduced rapid progressive motility affected particularly IVF, with a decrease of the fertilization rate and number of embryos at day 2 when progressive motility was lower than 32%. Paternal age also had a negative effect. Although it was difficult to eliminate the bias linked to the woman's age, pregnancy rate was reduced in IVF and ICSI when the father was older than 51 and the mother older than 37 years.

CONCLUSIONS

These results allow adjusting our strategies of fertilization technique and embryo transfer. In the case of severe oligospermia, transfer should be carried out at the cleaved embryo stage (day 2-3) due to the very low blastulation rate. When the man is older than 51 years, couples should be aware of the reduced success rate, especially if the woman is older than 37 years. Finally, promising research avenues should be explored, such as the quantification of free sperm DNA, to optimize the selection of male gametes.

Sperm morphological abnormalities visualised at high magnification predict embryonic development, from fertilisation to the blastocyst stage, in couples undergoing ICSI

PURPOSE

To investigate the predictive value of the motile sperm organelle morphology examination (MSOME) on embryo morphology.

METHODS

The morphologies of 540 embryos obtained from 60 couples undergoing ICSI were evaluated from days 1 to 5 of development and were examined for associations with the percentages of morphologically normal paternal sperm and of the paternal sperm with large nuclear vacuoles (LNVs) as determined by MSOME.

RESULTS

An increased percentage of LNV sperm was associated with increased odds of a zygote presenting with pronuclear abnormalities. It was also associated with decreased odds of (i) normal cleavage on days 2 and 3 of development, (ii) the presence of a high-quality embryo on day 3, (iii) the development of an embryo to the blastocyst stage, and (iv) an embryo possessing a normal trophectoderm and inner cell mass. The calculated areas under the curves differed for the embryos that did and did not develop to the blastocyst stage and for the high- and low-quality blastocysts. The optimal cut-off value for the percentage of LNV sperm that maximised proper blastocyst formation was ≤24.5 %, and the cut-off value that maximised blastocyst quality was ≤19.5 %.

CONCLUSIONS

These results suggest a very early onset of paternal influences on embryo development. The evaluation of the incidence of vacuoles by MSOME may significantly improve upon the prognostic information provided by conventional semen analyses.

Embryo culture and selection: morphological criteria

In this chapter, we have outlined the various morphological criteria for selection of the best embryo at each important milestone encountered in the progress from the oocyte to the blastocyst. As Gerris et al. stated, a combination of one, two, or even three selection points should lead to a more accurate selection of the best embryo, as no one criterion is better than the other. An embryo that fails to meet the entire set of selection criteria must be avoided as culture cannot correct an impaired embryo.

Comparison of the transfer of equal numbers of blastocysts versus cleavage-stage embryos after repeated failure of in vitro fertilization cycles

PURPOSE

To evaluate the efficacy of blastocyst transfer in women with at least two previously unsuccessful in vitro fertilization-embryo transfer (IVF-ET) attempts.

METHODS

Retrospective analysis of 238 couples (with previous implantation failures) had equal number (two) of cleavage-stage embryos (n = 143) or blastocysts (n = 95) transferred in the same IVF center.

RESULTS

The clinical pregnancy rates and live-birth rates were similar in the cleavage-stage embryo transfer group and the blastocyst group (35.6% vs. 40% and 32.1% vs. 35.7%; p > 0.05, respectively). Miscarriage rates (9.8% vs. 10.5%) and multiple pregnancy rates (15.6% vs. 23.6%) did not differ. Although implantation rate was higher with blastocyst transfer than that with day 3 transfer, it did not reach to a statistical significance (24.7% and 19%, respectively, p > 0.05).

CONCLUSION

Blastocyst transfer in ICSI cycles does not yield a better outcome than that obtained with cleavage-stage embryos in women who had unsuccessful IVF attempts previously.

Conventional IVF as a laboratory strategy to rescue fertility potential in severe poor responder patients: the impact of reproductive aging

OBJECTIVE

To investigate whether laboratory strategies can improve in vitro fertilization (IVF) outcome in poor responder patients. We compared the effectiveness of conventional IVF and intra cytoplasmic sperm injection (ICSI) in assisted reproductive technologies cycles in which only one or two oocytes were retrieved at ovarian pick up, in the absence of male infertility.

DESIGN

Retrospective analysis of 425 cycles in 386 poor responder patients.

INTERVENTION(S)

Standard stimulation protocol with gonadotropins and gonadotropin releasing hormone (GnRH) antagonist.

MAIN OUTCOME MEASURE(S)

Fertilization rate, cleavage rate, good-quality embryo rate, implantation rate, clinical pregnancy rate (PR) and miscarriage rate.

RESULTS

IVF was found to be more advantageous for implantation and PR, especially in patients under 35 years and in women aged between 35 and 38 years. No differences were noted in the other parameter evaluated. Patients aged over 38 years showed no difference using the two techniques.

CONCLUSION

The employment of ICSI in the absence of a male factor can reduce reproductive outcome in poor responder. Probably because of aging-related defects overcoming the advantage of sperm selection, the choice of IVF technique is not relevant to reproductive success when oocyte quality is compromised by reproductive aging. Although further randomized trials are needed to confirm our results, we propose that, in absence of male infertility, conventional IVF might be the technique of choice in young patients, especially in those aged below 35 years.

Pregnancy outcomes of day 5 embryo transfer in patients at high risk of developing ovarian hyperstimulation syndrome and analysis of factors affecting blastocyst formation

OBJECTIVES

To investigate the effects of day 5 embryo transfer (D5ET) compared with day 3 embryo transfer (D3ET) in patients at high risk of developing ovarian hyperstimulation syndrome (OHSS); to analyse factors affecting blastocyst formation.

METHODS

Patients at high risk of developing OHSS underwent either D3ET or D5ET.

RESULTS

A total of 253 patients received D3ET; 263 received D5ET. The number of embryos transferred was lower in the D5ET group than in the D3ET group. There were no between-group differences in pregnancy or live birth rates. Implantation rate was higher, and multifetation rate lower, in the D5ET group compared with the D3ET group. In addition, the incidence of moderate or severe OHSS was lower in the D5ET group than in the D3ET group. The woman's age, gonadotrophin dosage and insemination method were associated with the quality of blastocyst formation.

CONCLUSIONS

In patients with a high risk of developing OHSS, compared with D3ET, D5ET decreased the multifetation rate and the incidence of moderate or severe OHSS, but did not affect the pregnancy or live birth rate. Women of a younger age, who have had an appropriate gonadotrophin dose and insemination by in vitro fertilization, are suitable candidates for blastocyst transfer.

The male factor of infertility should not be an issue for the selection of patients for extended embryo culture programmes

This study evaluated the influence of sperm origin and basic sperm parameters on blastocyst implantation competence. The study included 2912 embryos obtained from 370 patients undergoing intracytoplasmic sperm injection cycles, with embryo transfer on day 5 of development. The embryos were divided into experimental groups according to their origin: (i) embryos originated from ejaculated-derived spermatozoa (Ejaculated group, n = 2093), from epididymal-derived spermatozoa (Epididymal group, n = 463) and from testicular-derived spermatozoa (Testicular group, n = 356). The groups were compared in relation to their blastocyst implantation competence. In addition, the influence of sperm parameters on blastocyst implantation was investigated. The sperm origin was determinant to the success of implantation. When blastocysts originating from testicle-derived spermatozoa were transferred, 66.4% implanted, while only 35.8 and 48.6% of blastocysts originated from epididymis- and ejaculate-derived spermatozoa implanted respectively (p = 0.001). The sperm volume and concentration were increased in cycles in which the implantation rate was 100 compared to the 0% implantation rate cases; however, the sperm motility and morphology did not differ among the groups. These results suggest that, with the exception of sperm volume and concentration, the male factor of infertility should not be an issue for the selection of patients for extended embryo culture programmes, even when azoospermic patients are considered.

Focus on intracytoplasmic morphologically selected sperm injection (IMSI): a mini-review

Intracytoplasmic sperm injection (ICSI) is the recommended treatment in many cases of male-factor infertility. Several studies have demonstrated a positive correlation between optimal sperm morphology and positive ICSI outcomes. In fact, spermatozoa with severe abnormalities of the head are well documented to be associated with low fertilisation, implantation and pregnancy rates. However, a spermatozoon which is classified as 'normal' by microscopic observation at low magnification could contain ultrastructural defects that impair both the fertilisation process and embryonic development. The intracytoplasmic morphologically selected sperm injection (IMSI) procedure changed the perception of how a spermatozoon suitable for injection should appear. Sperm selection is carried out at ×6000 magnification, allowing improved assessment of the sperm nucleus. Currently, standardized clinical indications for IMSI are lacking and the candidates are selected on the grounds of their medical history or of a careful analysis of the sperm suspension. Further prospective randomized studies are needed to confirm the advantages of IMSI in specific groups of patients. In addition to providing a brief overview of the IMSI procedure, this study aims to review the literature, which explains the theoretical basis and the clinical outcomes of this technique. Several reports show that IMSI is associated with improved implantation and clinical pregnancy rates as well as lower abortion rates when compared to ICSI. Although a possible correlation between the sperm's abnormal nucleus shape, increased DNA fragmentation and negative laboratory and clinical outcomes has been long investigated, the results are conflicting.

Intracytoplasmic morphologically selected sperm injection (IMSI) after repeated IVF or ICSI failures: a prospective comparative study

OBJECTIVE

Sperm morphology plays a significant role in assisted reproductive technologies and is associated with high implantation rates. The objective of this study was to evaluate the outcome of intracytoplasmic morphologically selected sperm injection (IMSI) after repeated failures of conventional in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) techniques.

STUDY DESIGN

In a prospective study in which couples acted as their own controls, 75 infertile couples were offered IMSI after at least two previous IVF or ICSI failures. The main outcome measures were embryo quality and number of blastocysts obtained.

RESULTS

The percentage of top quality embryos obtained at day 2 was increased in IMSI compared to IVF/ICSI cycles (89.8% versus 79.8%; p=0.009). Extended embryo culture was possible in 41.3% of IMSI cycles versus 26.7% of IVF/ICSI cycles (p=0.04), and the mean number of blastocysts obtained was higher in IMSI cycles (1.5±1.9) than in IVF/ICSI cycles (1.0±1.2) (p=0.03). Moreover, IMSI resulted in clinical pregnancy and birth rates of respectively 29.3% and 18.6%.

CONCLUSION

After two or three IVF/ICSI failures, IMSI seems to give better embryo quality and more blastocysts, which allow more embryo transfers at the blastocyst stage. This study supports the use of sperm ultramorphology examination as an independent test to be proposed after repeated IVF or ICSI failures.

Intracytoplasmic morphology-selected sperm injection

Approximately 40% of sterility in couples can be attributed to male subfertility and intracytoplasmic sperm injection (ICSI) has become a powerful tool in assisted reproduction to overcome male infertility. Intracytoplasmic morphologically selected sperm injection (IMSI) is an advanced and sophisticated method of ICSI, where prior to sperm injection the morphology of the sperm is evaluated under high magnification. In addition, the IMSI procedure involves a few minor modifications in sperm preparation which are not carried out during the conventional ICSI procedure, such as the use of MSOME criteria, the requirement for a glass-bottomed dish for selection, prolonged sperm manipulation following separation from the seminal fluid, and sperm storage prior to microinjection. These variations are discussed in this chapter.

Patient selection criteria for blastocyst transfers in extended embryo culture programs

PURPOSE

To identify the correlation between different cycles, patient factors and blastocyst characteristics.

METHODS

The study included 420 patients undergoing ICSI cycles and 2781 graded blastocysts, which took into account the blastocyst quality. The correlations between the blastocyst parameters and the patient and cycle characteristics were assessed.

RESULTS

The blastocyst development was negatively correlated with the maternal age, BMI and dose of FSH. The ICM was negatively correlated with the FSH dose, whereas the TE quality was influenced by the FSH dose, the maternal age and the number of retrieved oocytes. The embryo morphology on days two and three may predict the blastocyst developmental competence.

CONCLUSIONS

Older patients and patients with high BMI should not be included in extended embryo culture programmes. The extended culture may not favour embryos with poor morphology on days two and three of development. Additionally, a lower ovarian stimulation and decreased oocyte yields may lead to the development of high-quality blastocysts.

Effect of polyvinylpyrrolidone on sperm function and early embryonic development following intracytoplasmic sperm injection in human assisted reproduction

The objective here was to review the effects of polyvinylpyrrolidone (PVP) upon sperm function and embryonic development in humans. PVP has been used successfully in intracytoplasmic sperm injection (ICSI) to facilitate the handling and immobilization of sperm for both domestic animals and humans. In our previous reports, PVP solution exists locally in embryos injected during the early developmental period, and also exerts influence over the developmental capacity of such embryos. In other reports, PVP causes significant damage to sperm membranes that can be detected by transmission electron microscopy, and has been associated with chromosomal abnormalities in pregnancy derived from ICSI embryos. In some Japanese clinics, PVP-free media has been used for sperm immobilization in order to optimise safety. Consequently, it is strongly suggested that the success rate of fertilization and clinical pregnancy could be improved by using PVP-free solution for human ICSI. In conclusion, our interpretation of the available data is to perform ICSI without PVP or select a lower concentration of PVP solution in order to reduce safety for pregnancy and children born via ICSI.

Different sperm sources and parameters can influence intracytoplasmic sperm injection outcomes before embryo implantation

To evaluate the effects of sperm with different parameters and sources on the outcomes of intracytoplasmic sperm injection (ICSI), 1972 ICSI cycles were analyzed retrospectively. Groups 1 to 5 were composed of cycles using ejaculated sperm and were grouped according to sperm quantity, quality, and morphology into normal (288 cycles), or mild (329 cycles), moderate (522 cycles), severe (332 cycles), and extremely severe (171 cycles) oligozoospermia and/or asthenozoospermia and/or teratozoospermia (OAT) groups. Group 6 was composed of 250 cycles using testicular or epididymal sperm, and Group 7 consisted of 80 cycles using frozen-thawed sperm. We found that fertilization rates were gradually reduced from Groups 1 to 6, and reached statistical difference in Groups 5 and 6 (P<0.05). The high-quality embryo rate was higher in Group 1 than in Groups 2, 3, 5, 6, and 7 (P<0.05). No statistical differences were observed in the rates of embryo cleavage, clinical pregnancy, miscarriage, live-birth, premature birth, low birth weight, weeks of premature birth, average birth weight, or sex ratio for all seven groups (P>0.05). A total of nine cases of malformation were observed, with a malformation rate of 1.25% (9/719). In conclusion, different sperm sources and parameters can affect ICSI outcomes before embryo implantation. A full assessment of offspring malformation will require further study using a larger sample size.

Clinical outcomes of elective single morula embryo transfer versus elective single blastocyst embryo transfer in IVF-ET

PURPOSE

To compare the clinical outcomes of elective single morula embryo transfer (eSMET) versus elective single blastocyst embryo transfer (eSBET) in selected patients.

METHODS

This study was a retrospective study which analyzed for 271 cycles in women under 37 years of age who are undergoing their first or second trial of in vitro fertilization-embryo transfer (IVF-ET) from January 2008 to December 2009. The eSMET was performed on day 4 (n = 130) and the eSBET was conducted on day 5 (n = 141).

RESULTS

The clinical pregnancy rate (51.5% vs. 51.8%, p = 0.97), implantation rate (52.3% vs. 52.5%, p = 0.98), and live birth rate (39.2% vs. 44.7%, p = 0.36) were similar in the eSMET and eSBET groups, respectively. The miscarriage rate of the eSMET group (23.9%) was slightly higher than that of the eSBET group (13.7%) (p = 0.12), without reaching statistical significance. There was only one case of monozygotic twin pregnancy in each group.

CONCLUSIONS

The clinical outcomes of day 4 eSMET were comparable to those of day 5 eSBET. Therefore, day 4 eSMET is a viable option or an alternative to day 5 eSBET, with no difference in success rates.

Comparison of elective single cleavage-embryo transfer to elective single blastocyst-embryo transfer in human IVF-ET

OBJECTIVE

This study was carried out to compare the clinical outcome of elective single cleavage-embryo transfer (eSCET) to that of elective single blastocyst-embryo transfer (eSBET) in human IVF-ET.

METHODS

This study was a retrospective study which analyzed for 614 women who visited the Daegu Maria Clinic from August 2008 to December 2009. All were under 37 years old and had more than 8 mm of endometrial thickness on the day of hCG administration and at least one good quality embryo on day 3. The eSCETs were performed on day 3 (n=450) and the eSBETs were conducted on day 5 (n=164).

RESULTS

The numbers of retrieved oocytes, fertilized oocytes, and day 3 good quality embryos were significantly lower in the eSCET group (12.1±6.0, 8.2±4.6, and 4.2±3.1, respectively) compared to the eSBET group (16.7±7.2, 12.1±5.0, and 8.5±4.5, respectively; p<0.001). However, the clinical pregnancy, implantation, on-going pregnancy, and live birth rates of the eSCET group (46.7, 46.9, 40.0, and 36.7%, respectively) were not statistically different from those of the eSBET group (51.2, 51.8, 45.1, and 43.9%, respectively; p=0.318, 0.278, 0.254, and 0.103, respectively).

CONCLUSION

These results suggested that elective single embryo transfer should be performed regardless of the developmental stage to women less than 37 years old who had more than 8 mm of endometrial thickness on the hCG administration day and at least one good quality embryo on day 3 in order to reduce the twin pregnancy rate without reducing the whole pregnancy rate.

Reduction in exposure of human embryos outside the incubator enhances embryo quality and blastulation rate

Embryo quality is strongly dependent on the in-vitro culture environment. Conventionally, IVF/intracytoplasmic sperm injection (ICSI) embryos are examined microscopically every morning (from day 1 to day 6) to assess fertilization, cleavage and embryo quality. Consequently, the frequent exposure to non-optimal conditions outside the incubator may adversely affect embryonic viability and quality. Hence, this study investigated whether reduction of observation frequency outside the incubator can enhance blastocyst formation rate. A total of 285 IVF/ICSI cycles were divided into two groups. Embryos in the control group (103 cycles) were assessed out-of-incubator every day after insemination (day 1 to day 6; six times). In the experimental group (182 cycles), embryos were assessed four times, on days 1, 3, 5 and 6. The total blastocyst formation rate, day-5 blastocyst formation rate, proportion of good blastocysts and number of cryopreserved blastocysts per patient were significantly lower for the control group compared with the experimental group (42.5%, 31.4%, 50.7%, 1.72+/-1.55 versus 52.6%, 40.7%, 60.1%, 2.64+/-2.59, respectively, P<0.05); although there were no significant differences in the proportions of good embryos on day 3, blastocyst formation rate on day 6, clinical pregnancy rate and implantation rate. Hence, reduction of the observation frequency of embryos outside the incubator can enhance embryo quality and blastocyst formation rate.