Cumulative live birth rate and neonatal outcomes after early rescue ICSI: a propensity score matching analysis

STUDY QUESTION

Is early rescue ICSI (E-RICSI) an effective and safe technique compared to conventional ICSI?

SUMMARY ANSWER

Despite the higher multi-pronucleus (PN) rate compared to conventional ICSI, E-RICSI did not add extra risks to clinical and neonatal outcomes.

WHAT IS KNOWN ALREADY

Based on the finding that the second polar body was released in 80% of fertilized oocytes by 4 h after exposure to spermatozoa and in ∼90% of fertilized oocytes by 6 h, E-RICSI brings forward the timing of rescue ICSI to 6 h after initial insemination, and effectively prevents oocyte aging and embryo-uterus asynchrony. However, some researchers still voice concerns about the efficacy and safety of E-RICSI, and comparative studies are limited.

STUDY DESIGN SIZE DURATION

A retrospective cohort study was conducted on patients who underwent conventional ICSI or E-RICSI treatment between January 2015 and December 2020 at a university-affiliated hospital. Using 1:1 propensity score matching, 1496 cases entered each group.

PARTICIPANTS/MATERIALS SETTING METHODS

In total, 1496 couples undergoing conventional ICSI oocyte retrieval cycles and 1496 undergoing E-RICSI oocyte retrieval cycles were enrolled in this study, and basic clinical characteristics, embryologic data, clinical outcomes and neonatal data were compared between groups. The embryos in the E-RICSI group were divided into two subgroups: those fertilized by iIVF (IVF subgroup) and those fertilized by E-RICSI (E-RICSI subgroup); the embryologic data, clinical outcomes, and neonatal data for these subgroups were also compared with the conventional ICSI group. Logistic regression was used for statistical analysis with potential confounder adjustment.

MAIN RESULTS AND THE ROLE OF CHANCE

The 2PN rate, blastocyst formation rate, and viable blastocyst formation rate of the E-RICSI group were significantly lower compared to the conventional ICSI group (2PN rate: P < 0.001; blastocyst formation rate: P < 0.001; viable blastocyst formation rate: P = 0.004), and the multi-PN rate in the E-RICSI group was significantly higher than the conventional ICSI group (P < 0.001). However, the number of 2PN embryos, normal cleavage embryo rate, Day 3 high-quality cleavage embryo rate, and high-quality blastocyst rate were similar between groups. When considering the IVF embryos and E-RCSI embryos in the E-RICSI group independently, the 2PN rate of the conventional ICSI group was significantly lower than E-RICSI subgroup but higher than the IVF subgroup, whereas the blastocyst formation rate and viable blastocyst formation rate were higher than E-RICSI embryos but comparable to IVF embryos. As for the clinical and neonatal outcomes, the implantation rate of the E-RICSI subgroup was significantly lower than the IVF subgroup but comparable to the conventional ICSI group, while the low birthweight (LBW) rate was significantly lower compared with the conventional ICSI group but similar with the IVF subgroup. No other differences were observed among the three groups for cumulative clinical pregnancy rate, cumulative live birth rate, and the pregnancy outcomes per transfer including clinical pregnancy, ectopic pregnancy, miscarriage, and live birth, either in fresh or frozen embryo transfer cycles. Furthermore, neonatal outcomes, including cesarean section, sex ratio, LBW, preterm birth, and macrosomia, were similar among groups.

LIMITATIONS REASONS FOR CAUTION

This study is limited by the retrospective design, limited sample size, and short follow-up period. However, our study underlies the need for large-scale, multi-center randomized controlled trials with long-term follow-up.

WIDER IMPLICATIONS OF THE FINDINGS

Short-term insemination (3 h) combined with E-RICSI may be a safe and effective method to prevent the occurrence of total fertilization failure, and patients with normal or borderline sperm could be encouraged to try IVF first.

STUDY FUNDING/COMPETING INTERESTS

This study was supported by grants from the National Key & Development Program of China (No. 2021YFC2700603) and the National Natural Science Foundation of China (No. 81801443). The authors declare no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

Comparing the pregnancy outcomes of Re‑ICSI and ICSI embryos in fresh ET and FET cycles

Early rescue intracytoplasmic sperm injection (Re-ICSI) can prevent total fertilization failure (TFF) during conventional in vitro fertilization (IVF). However, the implantation rate of Re-ICSI embryos is lower than that of direct ICSI during fresh embryo transfer (ET). The aim of the present study was to investigate the effect of frozen ET (FET) after Re-ICSI. In the present retrospective study, primary infertility patients that underwent the first Re-ICSI and ICSI treatment, were studied. The clinical pregnancy rate, implantation rate, ectopic pregnancy, abortion rate and live birth rate were analyzed between the Re-ICSI and ICSI groups in fresh ET and FET cycles. The average age of patients between Re-ICSI and ICSI groups in fresh ET and FET cycles was (29.0±3.2 vs. 29.1±3.1, and 29.1±3.3 vs. 28.9±3.0), respectively (P>0.05). Compared with ICSI embryos, the clinical pregnancy, implantation and live birth rates of Re-ICSI embryos were lower in fresh ET cycles. By contrast, there were no significant differences in the pregnancy, implantation and live birth rates between the Re-ICSI and ICSI embryos during the FET cycles. Re-ICSI coupled with FET may overcome the impaired outcomes in fresh ET.

Day after rescue ICSI: eliminating total fertilization failure after conventional IVF with high live birth rates following cryopreserved blastocyst transfer

STUDY QUESTION

What is the impact of day after rescue ICSI (r-ICSI) on success of fresh and frozen embryo transfers?

SUMMARY ANSWER

The use of r-ICSI can virtually allay fears of total fertilization failure (TFF) after conventional IVF (C-IVF) and achieve high live birth rates after frozen blastocyst transfer.

WHAT IS KNOWN ALREADY

More infertility clinics have resorted to the use of ICSI in place of C-IVF in IVF treatment owing to fear of TFF or a low fertilization rate. r-ICSI has been attempted either on the day of IVF or the day after. Day after r-ICSI has proved unsuccessful in the past.

STUDY DESIGN, SIZE, DURATION

A retrospective data analysis was performed of 16 608 qualifying cases between April 2010 and July 2021 conducted at a single private academically affiliated fertility clinic.

PARTICIPANTS/MATERIALS, SETTING, METHODS

r-ICSI was performed principally on patients with >4 metaphase II oocytes, showing no signs of fertilization 18 h after C-IVF. C-IVF was performed on patients who had >4 million total motile sperm after preparation. r-ICSI was then performed 18-24 h after insemination, using the sperm sample from the previous day. r-ICSI fertilization rates, cryopreservation of cleavage and blastocysts embryos, and pregnancy rates after fresh or frozen transfer were then assessed.

MAIN RESULTS AND THE ROLE OF CHANCE

r-ICSI was performed on 377 patients (2.3% of eligible retrieval cycles) who had a mean (±SD) female and male age of 35.9 ± 4.5 and 38.1 ± 9.1 years, respectively. A total of 5459 oocytes were initially retrieved. Of the oocytes undergoing r-ICSI, 2389 (49.5%) fertilized normally, and 205 (54.4%) patients underwent a fresh embryo transfer. The live birth rates were 23/186 (12.3%) for fresh cleavage and 5/19 (26.3%) for fresh blastocyst stage transfers. In 145 cycles a blastocyst was frozen, and 137 transfers were performed with a 64/137 (46.7%) live birth rate. Of the 377 cycles receiving r-ICSI only, 25 of the qualifying cases failed to have any fertilization, reducing TFF to 25/16 608 (0.15%).

LIMITATIONS, REASONS FOR CAUTION

This was a single-center retrospective study on a specific subset of patients, which may limit its generalizability to other clinics.

WIDER IMPLICATIONS OF THE FINDINGS

r-ICSI allows a second opportunity to fertilize oocytes despite poor initial outcomes. Patients who had a frozen blastocyst transfer achieved high live birth rates, indicating that a resynchronization of the embryo with the endometrium can optimize r-ICSI cases. r-ICSI allays fears of TFF when using C-IVF, providing evidence that the overuse of ICSI in patients without male factor may not be warranted.

STUDY FUNDING/COMPETING INTEREST(S)

The study was internally funded by Boston IVF. The authors declare that they have no conflict of interest in relation to the data published in the article.

TRIAL REGISTRATION NUMBER

N/A.

ACROSIN deficiency causes total fertilization failure in humans by preventing the sperm from penetrating the zona pellucida

STUDY QUESTION

Does a homozygous nonsense mutation in ACR lead to total fertilization failure (TFF) resulting in male infertility in humans?

SUMMARY ANSWER

A novel homozygous nonsense mutation of ACR (c.167G>A, p.Trp56X) was identified in two infertile brothers and shown to cause human TFF.

WHAT IS KNOWN ALREADY

ACROSIN, encoded by ACR, is a major acrosomal enzyme expressed only in the acrosome of the sperm head. Inhibition of acrosin prevents sperm penetration of the zona pellucida (ZP) in several species, including humans. Acr-knockout in hamsters causes male infertility with completely blocked fertilization. Of note, there are no reports of ACR mutations associated with TFF in humans.

STUDY DESIGN, SIZE, DURATION

Whole-exome sequencing (WES) was used for the identification of pathogenic genes for male factor TFF in eight involved couples.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Data from eight infertile couples who had experienced TFF during their IVF or ICSI attempts were collected. Functional assays were used to verify the pathogenicity of the potential genetic factors identified by WES. Subzonal insemination (SUZI) and IVF assays were performed to determine the exact pathogenesis of TFF caused by deficiencies in ACROSIN.

MAIN RESULTS AND THE ROLE OF CHANCE

A novel homozygous nonsense mutation in ACR, c.167G>A, p.Trp56X, was identified in two additional primary infertile brothers whose parents were first cousins. This rare mutation caused ACROSIN deficiency and acrosomal ultrastructural defects in the affected sperm. Spermatozoa lacking ACROSIN were unable to penetrate the ZP, rather than hampering sperm binding, disrupting gamete fusion, or preventing oocyte activation. These findings were supported by the fertilization success of SUZI and ICSI attempts, as well as the normal expression of ACTL7A and PLCζ in the mutant sperm, suggesting that ICSI without remedial assisted oocyte activation is an optimal treatment for ARCOSIN-deficient TFF.

LIMITATIONS, REASONS FOR CAUTION

The absence of another independent pedigree to support our argument is a limitation of this study.

WIDER IMPLICATIONS OF THE FINDINGS

The findings expand our understanding of the genes involved in human TFF, providing information for appropriate genetic counseling and fertility guidance for these patients.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by the National Natural Science Foundation of China (grant no. 82201803, 81901541, 82271639, and 32000584), University Synergy Innovation Program of Anhui Province (GXXT-2019-044), and the Nonprofit Central Research Institute Fund of the Chinese Academy of Medical Sciences (grant no. 2019PT310002). The authors declare no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

Assisted gamete treatment to pinpoint acquired meiotic maturity and overcome oocyte activation deficiency contributed by both gametes

Objective

To treat couples with total fertilization failure (TFF) based on a combined oocyte- and sperm-related oocyte activation deficiency by optimizing oocyte response to chemical activation with calcium ionophore.

Design

Case report.

Setting

Tertiary Hospital.

Patients

Two couples with a history of TFF after intracytoplasmic sperm injection intracytoplasmic sperm injection (ICSI).

Interventions

To overcome oocyte-related oocyte activation deficiency (OAD), extended in vivo/in vitro oocyte maturation was performed to enhance ooplasmic maturity; to address sperm-related OAD, assisted gamete treatment (AGT) was performed to trigger oocyte activation.

Main outcome measures

Treatment cycle outcomes for the 2 couples undergoing ICSI with extended oocyte maturation (EOM) and AGT.

Results

We identified 2 couples with TFF after ICSI because of a combined factor of OAD confirmed by phospholipase C zeta expression and genomic assessment. Initial AGT treatment alone failed to enhance fertilization, suggesting superimposed oocyte dysmaturity prohibiting oocytes from responding to chemical stimuli. To address this complex form of OAD, in couple 1, 27 oocytes out of 34 retrieved presented normal metaphase II spindles after EOM; ICSI with AGT yielded a fertilization rate of 63.0% (17/27). All 17 zygotes were cryopreserved initially. Two embryos were thawed and transferred, yielding a monochorionic diamniotic twin pregnancy. Couple 2 underwent 3 ICSI cycles with EOM and AGT; 91.4% (32/35) of oocytes displayed normal metaphase II spindle and achieved an overall fertilization rate of 43.8% (14/32). A total of 12 blastocysts were cryopreserved. A single 46XY blastocyst was thawed and transferred, resulting in a singleton pregnancy.

Conclusions

Our study has demonstrated the usefulness of EOM by targeting spindle presence to enhance chemical responses to AGT.

Novel variants in ACTL7A and PLCZ1 are associated with male infertility and total fertilization failure

Total fertilization failure (TFF), which refers to fertilization failure in all mature oocytes, accounting for 5%-10% of in vitro fertilization (IVF) cycles and 1%-3% of intracytoplasmic sperm injection (ICSI) cycles in human. In this study, we recruited three unrelated primary infertile men with repeated cycles of TFF and performed whole-exome sequencing to identify the potential pathogenic variants. We identified homozygous or compound-heterozygous variants of paternal-effect genes ACTL7A and PLCZ1 that followed a Mendelian recessive inheritance pattern. Novel homozygous nonsense variant in ACTL7A [c.C146G: p.S49*] was identified in case 1, who came from a consanguineous family. Ultrastructural observation of ACTL7A-mutated spermatozoa by transmission electron microscopy (TEM) indicated that apparent increased thickness of perinuclear matrix and the acrosome was detached from the nuclear envelop. Besides, two novel compound-heterozygous variants in PLCZ1 were identified in case 2 [c.1174+3A>C:p.?; c.A1274G:p.N425S] and case 3 [c.136-1G>C:p.?; c.G1358A:p.G453D]. Mutated spermatozoa from case 2 with reduced expression of PLCZ1 showed apparent acrosome detachment by TEM analysis. And ICSI with assisted oocyte activation (ICSI-AOA) treatment can partly rescue the TFF. Taken together, our findings revealed that novel biallelic variants in the paternal-effect genes ACTL7A and PLCZ1 were associated with human TFF, which expanding the spectrum of genetic causes and facilitating the genetic diagnosis of male infertility with TFF.

Predicting the unexpected total fertilization failure in conventional in vitro fertilization cycles: What is the role of semen quality?

Background: Male and female gametes factors might contribute to the total fertilization failure (TFF). In first in vitro fertilization (IVF) cycles, decision-making of insemination protocol was mainly based on semen quality for the contribution of female clinical characteristics to TFF remained obscure. The purpose of the study was to evaluate the role of semen quality in predicting unexpected TFF. Methods: A single-center retrospective cohort analysis was performed on 19539 cycles between 2013 and 2021. Two algorithms, a Least Absolute Shrinkage and Selection Operator (LASSO) and an Extreme Gradient Boosting (Xgboost) were used to create models with cycle characteristics parameters. By including semen parameters or not, the contribution of semen parameters to the performance of the models was evaluated. The area under the curve (AUC), the calibration, and the net reclassification index (NRI) were used to evaluate the performance of the models. Results: The prevalence of TFF were .07 (95%CI:0.07-0.08), and .08 (95%CI:0.07-0.09) respectively in the development and validation group. Including all characteristics, with the models of LASSO and Xgboost, TFF was predicted with the AUCs of .74 (95%CI:0.72-0.77) and .75 (95%CI:0.72-0.77) in the validation group. The AUCs with models of LASSO and Xgboost without semen parameters were .72 (95%CI:0.69-0.74) and .73 (95%CI:0.7-0.75). The models of LASSO and Xgboost with semen parameters only gave the AUCs of .58 (95%CI:0.55-0.61) and .57 (95%CI:0.55-0.6). For the overall validation cohort, the event NRI values were -5.20 for the LASSO model and -.71 for the Xgboost while the non-event NRI values were 10.40 for LASSO model and 0.64 for Xgboost. In the subgroup of poor responders, the prevalence was .21 (95%CI:0.18-0.24). With refitted models of LASSO and Xgboost, the AUCs were .72 (95%CI:0.67-0.77) and .69 (95%CI:0.65-0.74) respectively. Conclusion: In unselected patients, semen parameters contribute to limited value in predicting TFF. However, oocyte yield is an important predictor for TFF and the prevalence of TFF in poor responders was high. Because reasonable predicting power for TFF could be achieved in poor responders, it may warrant further study to prevent TFF in these patients.

Influence of the sperm DNA fragmentation index on the outcome of rescue ICSI and the clinical value of rescue ICSI

OBJECTIVES

As a remedy for the failure of in vitro fertilization (IVF), rescue intracytoplasmic sperm injection (R-ICSI) has been widely carried out, but it has failed to significantly improve the fertilization rate and clinical pregnancy rate. Sperm DNA fragmentation index (DFI) was highly correlated with pregnancy outcome of artificial assisted reproduction. This study aims to investigate the effect of the sperm DFI on the outcome of R-ICSI and the clinical value of R-ICSI.

METHODS

This retrospective analysis was conducted among 140 infertile couples receiving R-ICSI in from January 2014 to December 2019. The subjects were assigned into a total fertilization failure (TFF)+low DFI group (R-ICSI after TFF and DFI<30%) (n=63), a TFF+high DFI group (R-ICSI after TFF and DFI≥30%) (n=16), a partial fertilization failure (PFF)+low DFI group (R-ICSI after PFF and DFI<30%) (n=52), a PFF+high DFI group (R-ICSI after PFF and DFI≥30%) (n=9). All transferred embryos were come from R-ICSI. The general clinical data [infertility duration, male age, female age, basal serum level of follicle stimulating hormone (FSH), basal serum level of luteinizing hormone (LH), antral follicle count, endometrial thickness of human chorionic gonadotropin (HCG) day, and eggs] and R-ICSI cycle outcomes (fertilization rate, normal fertilization rate, cleavage rate, good embryo rate, implantation rate, clinical pregnancy rate and live birth rate) were analyzed. In addition, the effect of R-ICSI on the fertilization outcome of conventional IVF total fertilization failure and partial fertilization failure was explored.

RESULTS

There was no significant difference in the general clinical data and R-ICSI cycle outcome between the TFF+low DFI group and the TFF+high DFI group (all P>0.05). There was no significant difference in the general clinical data between the PFF+low DFI group and the PFF+high DFI group (all P>0.05). The fertilization rate and normal fertilization rate in the PFF+low DFI group were significantly higher than those in the PFF+high DFI group (85.40% vs 72.41%, 71.90% vs 58.62%, respectively; both P<0.05). However, there was no significant difference in cleavage rate, good embryo rate, implantation rate, clinical pregnancy rate, and live birth rate between the 2 groups (all P>0.05). The R-ICSI cycle of TFF: A total of 79 fresh cycles, 57 fresh transplant cycles, a total of 761 unfertilized oocytes, and 584 M II oocytes were treated with R-ICSI, the fertilization rate was 83.22%, the normal fertilization rate was 75.51%, the cleavage rate was 98.15%, the good embryo rate was 40.74%, the implantation rate was 30.56%, and the clinical pregnancy rate was 43.86%; 29 live births were obtained. The R-ICSI cycle of PFF: A total of 61 fresh cycles, 31 fresh transplant cycles, a total of 721 unfertilized oocytes, and 546 M II oocytes were treated with R-ICSI; the fertilization rate was 83.33%, the normal fertilization rate was 69.78%, the cleavage rate was 97.36%, the good embryo rate was 44.39%, the implantation rate was 25.42%, and the clinical pregnancy rate was 45.16%; 12 live births were obtained.

CONCLUSIONS

In the case of partial fertilization failure of IVF, the sperm DFI affects the fertilization rate and normal fertilization rate of R-ICSI; whether it is a TFF of IVF or PFF of IVF, ICSI can be used as an effective remedy way.

Novel bi-allelic variants in ACTL7A are associated with male infertility and total fertilization failure

STUDY QUESTION

What are the genetic causes of total fertilization failure (TFF) in a proband suffering from male infertility?

SUMMARY ANSWER

Novel compound heterozygous variants (c.[463C>T];[1084G>A], p.[(Arg155Ter)];[(Gly362Arg)]) in actin-like protein 7A (ACTL7A) were identified as a causative genetic factor for human TFF.

WHAT IS KNOWN ALREADY

ACTL7A, an actin-related protein, is essential for spermatogenesis. ACTL7A variants have been reported to cause early embryonic arrest in humans but have not been studied in human TFF.

STUDY DESIGN, SIZE, DURATION

We recruited a non-consanguineous family whose son was affected by infertility characterized by TFF after ICSI. Whole-exome sequencing was used to identify the potential pathogenic variants. Artificial oocyte activation (AOA) after ICSI was performed to overcome TFF and any resulting pregnancy was followed up.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Sanger sequencing was performed to validate the variants. Pathogenicity of the identified variants was predicted by in silico tools. The ultrastructure of spermatozoa was studied by transmission electron microscopy (TEM). Immunofluorescence staining and western blotting were used to investigate the mechanism of the variants on the affected spermatozoa.

MAIN RESULTS AND THE ROLE OF CHANCE

Novel compound heterozygous variants in ACTL7A (c.[463C>T];[1084G>A], p.[(Arg155Ter)];[(Gly362Arg)]) were identified in a family with TFF after ICSI. In silico analysis predicted that the variants lead to a disease-causing protein. TEM showed that the ACTL7A variants caused ultrastructural defects in the acrosome and perinuclear theca. Protein expression of ACTL7A and phospholipase C zeta, a key sperm-borne oocyte activation factor, was significantly reduced in the affected sperm compared to healthy controls, suggesting that the ACLT7A variants lead to an oocyte activation deficiency and TFF. AOA by calcium ionophore (A23187) after ICSI successfully rescued the TFF and achieved a live birth for the patient with ACTL7A variants.

LIMITATIONS, REASONS FOR CAUTION

Given the rarity of sperm-associated TFF, only one family with an only child carrying the ACTL7A variants was found. In addition, the TFF phenotype was not assessed in two or more ICSI cycles, due to the intervention in ICSI with AOA after one failed ICSI cycle. Further studies should validate the ACTL7A variants and its effect on male infertility in larger independent cohorts.

WIDER IMPLICATIONS OF THE FINDINGS

: Our findings revealed a critical role of ACTL7A in male fertility and identified bi-allelic variants in ACTL7A associated with human TFF, which expands the genetic spectrum of TFF and supports the genetic diagnosis of TFF patients. We also rescued TFF by AOA and obtained a healthy live birth, which provides a potentially effective intervention for patients with ACTL7A pathogenic variants.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by the National Natural Science Foundation of China (81971374 and 81401267). No conflicts of interest were declared.

TRIAL REGISTRATION NUMBER

N/A.

A Novel Assisted Oocyte Activation Method Improves Fertilization in Patients With Recurrent Fertilization Failure

Total fertilization failure (TFF) occurs in 1–3% of total intracytoplasmic sperm injection (ICSI) cycles and can reoccur in subsequent cycles. Despite the high success rate with the application of assisted oocyte activation (AOA), there is still a small number of couples who cannot obtain fertilized eggs after conventional calcium (Ca²⁺) ionophores-based ICSI-AOA. Six couples experiencing repeated TFF or low fertilization (<10%) after ICSI and conventional ICSI-AOA were enrolled in this study. Compared with the regular ICSI group and the conventional ICSI-AOA group, the new AOA method, a combination of cycloheximide (CHX) and ionomycin, can significantly increase the fertilization rate from less than 10 up to approximately 50% in most cases. The normal distribution of sperm-related oocyte activation factor phospholipase C zeta (PLCζ1) in the sperms of the cases indicated the absence of an aberrant Ca²⁺ signaling activation. The results of the whole-embryo aneuploidies analysis indicated that oocytes receiving the novel AOA treatment had the potential to develop into blastocysts with normal karyotypes. Our data demonstrated that CHX combined with ionomycin was able to effectively improve the fertilization rate in the majority of patients suffering from TFF. This novel AOA method had a potential therapeutic effect on those couples experiencing TFF, even after conventional AOA, which may surmount the severe fertilization deficiencies in patients with a repeated low fertilization or TFF.

Relevance of Split In vitro Fertilization-Intracytoplasmic Sperm Injection Method of Insemination in Normozoospermic and Mildly Oligospermic Men: A Retrospective Study

Background:

Use of intracytoplasmic sperm injection (ICSI) is generally considered redundant in cases of normozoospermia, or mild male factor cases of infertility and conventional method of insemination is advocated. However, there is a risk of low fertilization or total fertilization failure (TFF) and to avoid this, split in vitro fertilization (IVF)-ICSI method of insemination is advised. In our study, we have shown that not only TFF is avoided with split method of insemination, but also cancellation of embryo transfer (ET) can be avoided in a significant number of IVF cycles.

Aims:

This study aimed to assess whether the IVF-ICSI split insemination method was able to reduce the risk of ET cancellation in couples with normal or mild sperm characteristics.

Settings and Design:

It is a retrospective study including a total of 107 split insemination cycles done at our center.

Materials and Methods:

The female partner's age was under 37 years, and at least ten oocytes were retrieved in all cycles. Sibling oocytes were randomly allocated to IVF or ICSI. Statistical analysis was carried out using Graphpad Prism, Instat.

Results and Conclusion:

The fertilization rate in oocytes kept in conventional IVF was significantly higher (79.8%) compared to that of oocytes injected through ICSI (69.1%). Only one couple had TFF. In majority of the cycles, i.e., 97 out of 107 cycles, the mode of insemination did not affect the fertilization rate or embryo quality. Nearly 28% of the cycles were saved from ET cancellation by adopting the split insemination method. “Split IVF-ICSI” approach can save a significant number of ART cycles and is found to be cost-effective as it avoids incurring the cost of two ART cycles.

Association between sperm mitochondrial ND2 gene variants and total fertilization failure

The objective of this study was to explore the association of sperm mitochondrial ND2 (MT-ND2) gene variants with total fertilization failure (TFF). A retrospective comparative study of 246 cases of fresh in vitro fertilization (IVF) cycles or half-intracytoplasmic sperm injection cycles in the Han Chinese population was performed from July 2011 to May 2017. A total of 59 cases undergoing TFF, and 187 control cases with normal fertilization (fertilization rates >50%) were included. The sperm mitochondrial genovariation was determined using nested sequencing. A total of 32 homoplasmic variants and 47 heteroplasmic variants of MT-ND2 gene were observed in this study. There were no significant differences in the frequencies of the 32 homoplasmic variants of MT-ND2 gene between the TFF and control groups. A total of 53 pair-wise comparisons were performed, and the general characteristics of the IVF failure and control subjects were adjusted in logistic models. Data suggested that there were no significant differences in the frequencies of point 4914, 5320, and 5426 heteroplasmic variants of MT-ND2 gene between the TFF and control groups. In addition, no significant difference was observed in the frequency of mtDNA haplogroup D or haplogroup G between the IVF failure group and the normal fertilization group. This study suggests that the MT-ND2 gene variants might not be associated with TFF.

ABBREVIATIONS

ATP: adenosine triphosphate; dNTP: deoxy-ribonucleoside triphosphate; FADH2: flavin adenine dinucleotide; FDR: false discovery rate; FSH: follicle-stimulating hormone; IVF: in vitro fertilization; LH: luteinizing hormone; MTATP6: mitochondrially encoded ATP synthase 6; MTCYB: mitochondrially encoded cytochrome b; mtDNA: mitochondrial DNA; MT-ND2: mitochondrial ND2; NADH: nicotinamide adenine dinucleotide; ND2: NADH dehydrogenase subunit 2; OXPHOS: oxidative phosphorylation; PCR: single nucleotide polymorphisms; SNPs: single nucleotide polymorphisms; TFF: total fertilization failure.

Total levels, localization patterns, and proportions of sperm exhibiting phospholipase C zeta are significantly correlated with fertilization rates after intracytoplasmic sperm injection

OBJECTIVE

To study the relationship of total levels, localization patterns, and proportions of sperm exhibiting phospholipase C zeta, with fertilization rates after in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI).

DESIGN

Laboratory study; controls vs. patients after IVF (n = 27) or ICSI (n = 17) treatment.

SETTING

Fertility center.

PATIENT(S)

A total of 44 semen samples, subjected to either IVF or ICSI treatment. Oocyte collection, ICSI or IVF, determination of sperm concentration and motility, and immunocytochemical analyses of phospholipase C zeta (PLCζ).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Percentages of sperm exhibiting PLCζ.

RESULT(S)

Significant positive correlation between ICSI fertilization rates and total levels, localization patterns, and the proportion (percentage) of sperm exhibiting PLCζ. Total levels, localization patterns, and the proportion of sperm exhibiting PLCζ are correlated with fertilization rates for ICSI, but not for IVF.

CONCLUSION(S)

Evaluating total levels, localization patterns, and proportions of PLCζ may represent a useful diagnostic tool for clinical purposes in men for whom IVF is not advised or has previously failed. This clinical study further supports the fundamental role of PLCζ in the oocyte activation process.

Total fertilization failure in intra-cytoplasmic sperm injection cycles--classification and management

In this retrospective cohort study we intended to propose a classification and preliminary management strategy for couples exhibiting total fertilization failure (TFF) in intra-cytoplasmic sperm injection (ICSI) cycles. Sixteen couples with a total of 27 cycles exhibiting TFF, age <40 and/or more than four M2 oocytes aspirated were enrolled. While TFF occurred in 4.3% of all 3723 ICSI cycles, in women younger than 40 with at least 5 M2 oocytes the TFF rate was 0.7%. Indications for ICSI were severe male factor and unexplained infertility. Of the 16 couples with TFF, 4 demonstrated a single episode of TFF, with either subsequent or former normal fertilizations, thus implying possible sporadic faulty laboratory conditions. Ten couples demonstrated repeated total or very low fertilization rates, hinting at a gamete defect not overcome by ICSI. Two couples experienced TFF in the first and only cycle performed at our unit. We conclude that initial and repeated TFF hints at severe gamete defects for which only donor gametes may prove successful while sporadic TFF events could simply imply a technical modifiable condition.

Human sperm devoid of germinal angiotensin-converting enzyme is responsible for total fertilization failure and lower fertilization rates by conventional in vitro fertilization

In conventional in vitro fertilization (IVF), complete failure of fertilization occurs in 5% to 15% of treatments. Although the causes may be unclear, sperm defects appear to be the major contributor. However, a convincing test is not yet available that can predict the risk of fertilization failure. In this study, we found that germinal angiotensin-converting enzyme (gACE) (also called testicular ACE) was undetectable in sperm from patients who had total fertilization failure (TFF) and lower fertilization rates (LFRs) by IVF based on Western blot and indirect immunofluorescence analyses. Additionally, almost all of the patients without gACE on sperm (23 of 25) manifested a TT genotype of the rs4316 single-nucleotide polymorphism of ACE. Overall, our results indicate that the absence of gACE expression is responsible for TFF and LFRs by IVF. The rs4316 polymorphism of ACE might be associated with infertility in those patients. We conclude that sperm lacking gACE may be recognized before commencing IVF and that the patients may be directed instead to consider intracytoplasmic sperm injection.

Rescue intracytoplasmic sperm injection: a systematic review

OBJECTIVE

To assess the feasibility, efficacy, and safety of rescue intracytoplasmic sperm injection (ICSI) in cases of fertilization failure, using a scientific literature search.

DESIGN

Systematic review.

SETTING

Centers for reproductive care.

PATIENT(S)

Infertility patients with total or partial fertilization failure during an IVF cycle.

INTERVENTION(S)

An electronic literature search was performed in PubMed from 1992 through May 2013. The search was then expanded by using listed references from selected articles.

MAIN OUTCOME MEASURE(S)

Pregnancy rate. The secondary outcome measures were fertilization rate, normal fertilization rate, cleavage rate, birth rate, and malformation rate.

RESULT(S)

Thirty-eight studies including 1,863 patients were included. The pooled pregnancy rate was 14.4%; 194 babies were delivered.

CONCLUSION(S)

Rescue ICSI can result in the delivery of a healthy newborn, although the pregnancy rates are low. The clinical evidence did not indicate an elevated rate of malformations, although the data are limited and incomplete.