Smooth endoplasmic reticulum aggregates in oocytes associated with increased risk of neonatal birth defects: A meta-analysis

INTRODUCTION

Previous studies have indicated the association between smooth endoplasmic reticulum aggregates (SERa+) and poorer medically assisted reproduction outcomes. However, the link between SERa+ and neonatal outcomes remains controversial and open for debate. A comprehensive meta-analysis on the relation between SERa+ and the risk of birth defects is needed.

MATERIAL AND METHODS

The literature search was conducted using the following databases: PubMed, Embase, Cochrane Libraries, Web of Science, and Chinese databases including China National Knowledge Infrastructure (CNKI) and Wan Fang from inception until July 2023. Risk ratio (RR) and 95% confidence interval (CI) were calculated by a fixed-effected model, while heterogeneity was assessed by forest plots and I2 statistic. Funnel plot was produced to assess publication bias. This meta-analysis has been registered on PROSPERO (CRD42022313387).

RESULTS

The search resulted in 122 studies, 14 of which met the inclusion criteria. The analysis of birth defects revealed a higher risk (RR = 2.17, 95%CI 1.24 to 3.81, p = 0.007) in children derived from SERa+ cycle compared to SERa- cycles (711 vs. 4633). Meanwhile, in a subgroup analysis, the risk of birth defects was significantly increased in the SERa+ oocytes group as compared with the sibling SERa- oocytes group (RR = 3.53, 95%CI 1.21 to 10.24, p = 0.02).

CONCLUSIONS

To conclude, our analysis indicated that SERa+ cycles/oocytes may have a potential risk of increased additional major birth defects comparing with SERa- cycles/oocytes. This conclusion may provide evidence-based support for clinicians in IVF clinical guidance and embryologists in prudent embryo selection strategy.

The Relationship Between Smooth Endoplasmic Reticulum Clusters in Metaphase II Oocytes and Embryological and Birth Outcomes in Infertile Couples

Background

To assess the relationship between oocytes with smooth endoplasmic reticulum cluster (SERc) and embryological and birth outcomes in infertile couples.

Methods

This was a descriptive study that included 231 infertile patients undergoing in vitro fertilization (IVF) with a total of 2447 mature oocytes (MII), of which 279 oocytes with SERc(+) from 100 patients, the remaining 2168 oocytes with SERc(-). Oocytes were evaluated for the presence or absence of the SERc simultaneously with intracytoplasmic sperm injection at 200x magnification using inverted microscopy - Observe D1.

Results

The mean age of patients was 32.05 ± 5.56 years. One hundred patients had at least one SERc(+) oocyte (with 279 SERc(+) and 956 SERc(-) oocytes). One hundred and thirty-one patients had 1212 SERc(-) oocytes. Fertilization outcomes and the rates of good-quality embryos on day 2 and day 5 did not differ between the SERc(+) and the SERc(-) groups. In the first frozen embryo transfer cycles, the clinical pregnancy rate in the group of patients with SERc(+) was not different with the SERc(-) group (61.1% vs 48.78%, p = 0.074, respectively). The live birth rate in the SERc(+) group was statistically significantly higher than the SERc(-) group (57.7% vs 43.9%, p = 0.045, respectively).

Conclusion

The fertilization rate, the quality of embryos on days 2 and 5 from oocytes with SERc(+) are similar to those with SERc(-). The live birth rate in the patients with SERc(+) group is statistically significantly higher than the SERc(-) group. There is no difference in clinical pregnancy rate between patients with and without SERc. Therefore, the exclusion of oocytes with SERc should not be recommended.

SERa-Positive Oocyte Intracytoplasmic Injection and Its Outcome: A Case Report

This case report describes the use of smooth endoplasmic reticulum aggregates-positive (SERa+) oocytes along with intracytoplasmic sperm injection (ICSI), supplemented with granulocyte-macrophage colony-stimulating factor (GM-CSF), aiming to enhance fertilization rates and reproductive outcomes. A 39-year-old woman, facing primary infertility for the past seven years, received assisted reproductive treatment (ART), which included adding GM-CSF to the culture medium and culture SERa+ oocytes before ICSI. Clinical results, embryo quality, fertilization rates, and other fertility parameters were used to track the patient's progress toward this individualized approach that led to a positive twin pregnancy and healthy twin babies.

Live birth rate per transfer is not impacted by the proportion of smooth endoplasmatic reticulum aggregates oocytes

BACKGROUND

Despite the data published to date, prognostic factors and the clinical impact of ICSI cycles with smooth endoplasmatic reticulum aggregates (SERa) positive oocytes remain unclear.

OBJECTIVE

Are the clinical outcomes of an ICSI cycle impacted by the proportion of oocytes with SERa?

MATERIALS AND METHODS

Retrospective study (2016-2019), including data from 2468 ovum pick-ups, performed in a tertiary university hospital. Cases are categorised based on the rate of SERa positive oocytes compared to the total number of MII oocytes: 0% (n=2097), <30% (n=262) and ≥30% (n=109).

MAIN OUTCOME MEASURES

Patient characteristics, cycle characteristics and clinical outcomes are compared between the groups.

RESULTS

Compared to SERa negative cycles, women with ≥30% SERa positive oocytes are older (36.2y vs. 34.5y, p<0.001), have lower anti-mullerian hormone levels (AMH) (1.6ng/ml vs. 2.3ng/ml, p<0.001), have received more gonadotropins (3227U vs. 2858IU, p=0.003), have a lower number of good quality day 5 blastocysts (1.2 vs. 2.3, p<0.001) and face more blastocyst transfer cancellation (47.7 vs. 23.7%, p<0.001). Women with <30% SERa positive oocytes are younger (33.8y, p=0.04), have higher AMH levels (2.6ng/ml, p<0.001), have more oocytes retrieved (15.1, p<0.001), have a higher number of good quality day 5 blastocysts (3.2, p<0.001) and have less transfer cancellations (14.9%, p<0.001) compared to SERa negative cycles A multivariate analysis shows no significant difference in cycle outcomes between the categories.

WHAT IS NEW?

Treatment cycles with ≥30% SERa positive oocytes are less likely to result in an embryo transfer when only non-SER oocytes are used. However, live birth rate per transfer is not affected by the proportion of SERa positive oocytes.

Metaphase II (MII) human oocytes with smooth endoplasmic reticulum clusters do not affect blastocyst euploid rate

OBJECTIVE

To investigate whether the rate of euploidy and pregnancy outcomes are affected by smooth endoplasmic reticulum clusters (SERc) and other metaphase II human oocyte dysmorphisms.

MATERIALS AND METHODS

Retrospective analysis of the morphologies of metaphase II (MII) human oocytes, which had developed into 590 biopsied blastocysts derived from 109 patients that received preimplantation genetic testing for aneuploidies (PGT-A) cycles between March 2013 and December 2017. The euploid rate of blastocysts that originated from morphologically abnormal or normal oocytes were analyzed. The chromosome status of the blastocysts was determined and analyzed by array comparative genomic hybridization (aCGH) or next generation sequencing (NGS) following trophectoderm biopsy.

RESULTS

According to the odds ratios obtained for each oocyte morphotype, no statistically significant relationship was found between oocyte dysmorphisms and euploid rate. Specifically, although SERc-positive oocytes had a higher rate of arrest at two pronuclei, or 2 PN (26.7% vs. 19.4%, p > 0.05), the blastocyst formation rate was not affected as compared with SERc-negative oocytes (40.0% vs. 38.6%, p > 0.05). Among nine euploid embryos derived from oocytes with SERc, three single euploid embryo transfers were performed, of which one resulted in blighted ovum, and two resulted in the births of two healthy, singleton term babies.

CONCLUSION

The results presented here suggest that oocyte dysmorphisms do not affect the euploidy rate of the blastocyst. The occurrence of SERc in the oocyte does not seem to impair the developing blastocyst nor does it interfere with good embryo formation rate and euploid rate. Thus, the embryos derived from SERc-positive oocytes could still be considered for embryo transfer if there are no other embryos available.

Oocytes With Smooth Endoplasmic Reticulum Aggregates May Not Impact Blastocyst Euploidy Rate

OBJECTIVE

To investigate whether the euploidy rate of blastocysts derived from smooth endoplasmic reticulum aggregates (SERa) positive cycles and oocytes are impacted.

DESIGN

Retrospective cohort study.

METHODS

A total of 601 preimplantation genetic testing (PGT) cycles with at least one oocyte retrieved in our center between April 2017 and May 2021 were initially included in the study. Women>35 years and PGT cycles with chromosomal structural rearrangements (PGT-SR) were excluded. Embryological and blastocyst ploidy outcomes were compared among SERa+ oocyte, sibling SERa- oocytes and oocytes in SERa- cycles.

RESULTS

No significant difference was observed among the SERa+ oocyte group, sibling SERa- oocyte group, and SERa- cycle group in the normal fertilization rate (82.1% vs. 77.8% vs. 83.1%, respectively, P=0.061), blastocyst formation rate (71.0% vs. 72.5% vs. 68.4%, respectively, P=0.393), good quality blastocyst formation rate (46.4% vs. 48.3% vs. 42.6%, respectively, P=0.198). No significant difference was observed in the euploidy rate (50.0% vs. 62.5% vs. 63.3%, respectively, P=0.324), mosaic rate (12.5% vs. 9.7% vs. 13.4%, respectively, P=0.506), and aneuploidy rate (37.5% vs. 27.8% vs. 23.2%, respectively, P=0.137) among the three groups.

CONCLUSION

Our results suggest that the euploidy rate of blastocysts derived from SERa+ cycles and oocytes may not be impacted.

Smooth Endoplasmic Reticulum Clusters in Oocytes From Patients Who Received Intracytoplasmic Sperm Injections Negatively Affect Blastocyst Quality and Speed of Blastocyst Development

Findings regarding the relationship between smooth endoplasmic reticulum clusters (SERCs) in oocytes and blastocyst development have been conflicting. In this study, the effects of SERCs on blastocyst quality and the speed of blastocyst development were evaluated. Patients who received intracytoplasmic sperm injections (ICSI) at our reproductive center from 2016 to 2020 were retrospectively analyzed. SERC (+) oocytes (n = 217) and SERC (-) oocytes (n = 822), as well as SERC (+) cycles (n = 146) and SERC (-) cycles (n = 1,951) were compared. There was no significant difference in embryological, clinical, and neonatal outcomes between the SERC (+) and SERC (-) cycles. The fertilization rate (73.9%), good quality blastocyst rate (26.7%) and the speed of blastocyst development (44.4%) were significantly lower (P < 0.05) in SERC (+) oocytes than in unaffected counterparts (86.2%, 44.1% and 63.4%, respectively). Furthermore, the proportion of blastocysts with trophectoderm (TE) grade C was significantly higher in the SERC (+) oocyte group than in the SERC (-) oocyte group (73.3 vs. 55.9%, P < 0.05). After adjusting for age, years of infertility, endometriosis, stimulation protocols (GnRHa), and male infertility, multiple logistic regression analysis revealed that the presence of SERCs in the oocytes significantly affected the speed of blastocyst development (odds ratio, 2.812; 95% CI, 1.257-6.292; P = 0.012). These findings suggest that the presence of SERCs in oocytes may negatively affect blastocyst quality and the speed of blastocyst development.

Occurrence of smooth endoplasmic reticulum aggregates in metaphase II oocytes: relationship with stimulation protocols and outcome of ICSI and IVF cycles

STUDY QUESTION

Is there any association between the appearance of smooth endoplasmic reticulum aggregates (SERa) in oocytes and ovarian stimulation, embryological, clinical and neonatal outcomes of ICSI and IVF cycles?

SUMMARY ANSWER

A suboptimal prolonged ovarian stimulation is detrimental to oocytes by inducing the occurrence of SERa, which reduces the reproductive potential of oocytes.

WHAT IS KNOWN ALREADY

Controlled ovarian stimulation recruits oocytes of different qualities. Based on current evidence, it was agreed that non-homogeneous cytoplasm may represent the normal variability among oocytes rather than a dysmorphism with developmental significance. The only exception is the appearance of SERa within the ooplasm. Owing to the lack of univocal evidence in this literature about the safety of injecting oocytes with SERa and the mechanism responsible for the occurrence of SERa, this topic is still a matter of debate.

STUDY DESIGN, SIZE, DURATION

A retrospective, longitudinal cohort study performed at a tertiary level public infertility center. We included 1662 cycles (180 SERa+ and 1482 SERa-) from 1129 women (age: 20-44 years) who underwent IVF/ICSI treatments in 2012-2019. The SERa+ cycles had at least one SERa+ oocyte in the oocyte cohort. The SERa- cycles had morphologically unaffected oocytes.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We collected stimulation data and embryological, clinical, neonatal outcomes of SERa- and SERa+ cycles and oocytes.

MAIN RESULTS AND THE ROLE OF CHANCE

Overall, 347 out of 12 436 metaphase II oocytes (2.8%) were affected by SER. We performed only 12 transfers involving at least one SERa+ embryo. Stimulation length (P = 0.002), serum progesterone (P = 0.004) and follicle size (P = 0.046) at trigger, number of retrieved (P = 0.004) and metaphase II (P = 0.0001) oocytes were significantly higher in SERa+ than SERa- cycles. Fertilization rate was significantly (P < 0.0001) reduced in SERa+ cycles and oocytes compared to SERa- counterparts. Embryos of SERa+ cycles had a lower blastocyst formation rate compared to embryos of SERa- cycles (P = 0.059). Statistical analysis according to a generalized estimating equation model performed at patient level demonstrated that the duration of ovarian stimulation was predictive of SERa+ oocytes appearance. The clinical success of SERa+ cycles was lower than SERa- cycles, although no differences in neonatal birthweights or malformations were recorded in sibling unaffected oocytes of SERa+ cycles.

LIMITATIONS, REASONS FOR CAUTION

Given that SERa+ oocytes were discarded in our center for years and transfers of embryos originating from affected oocytes were generally avoided, clinical outcomes of SERa+ cycles are largely attributable to the transfer of embryos derived from unaffected oocytes of SERa+ cycles and we did not have data about newborns from affected oocytes, since none of the transfers involving SERa+ embryos resulted in a progressive clinical pregnancy.

WIDER IMPLICATIONS OF THE FINDINGS

For the first time, we speculate that the late-follicular phase elevated serum progesterone caused by a suboptimal prolonged ovarian stimulation may be detrimental to the oocytes by inducing the occurrence of SERa, resulting in negative effects on their reproductive potential. This raises the question of whether some stimulation regimens could be worse than others and a change in stimulation protocol would reduce the possibility of producing oocytes with suboptimal maturation. In particular, our data highlight the importance of correct timing of the trigger in order to maximize oocyte collection, not only in terms of numerosity but also their reproductive potential.

STUDY FUNDING/COMPETING INTEREST(S)

None.

TRIAL REGISTRATION NUMBER

N/A.

Meta-analysis of the effects of smooth endoplasmic reticulum aggregation on birth outcome

BACKGROUND

Smooth endoplasmic reticulum aggregation (SERa, SER+) has been reported to increase the risk of birth malformations and other abnormal outcomes, miscarriage, and perinatal complications. Other studies, however, suggest that SER+ embryos may develop into healthy infants. One report indicates that 25% of in vitro fertilization (IVF) centers discard SER+ oocytes. Thus, we investigated the effect of SER+ on birth outcomes in IVF and intracytoplasmic sperm injection.

METHODS

We performed a literature search using PubMed, ScienceDirect, Cochrane, Embase, Ovid, and Scopus. We found a total of 1500 relevant studies between 1978 and 2020 and conducted a meta-analysis to study the effects of SER+ on live births, birth weight, and the number of metaphase II (MII) oocytes retrieved per cycle.

RESULTS

Eleven eligible studies were included. If the SER+ zygote was evaluated again at the embryo transfer (ET) stage, SER+ did not affect birth or infant body weight. Stimulated ovaries producing too many oocytes per cycle were positively correlated with SER+ (OR = 1.28, 95% CI = 0.41-2.15; p = 0.004). SER+ was positively correlated with oocyte maturation rate, and observed heterogeneity in a previous meta-analysis was likely due to maternal age. Our data also showed that SER+ cycles produced more oocytes but achieved the same number of births from ET.

CONCLUSIONS

The use of SER+ MII oocytes is rare, with the collection of many oocytes in 1 cycle potentially inducing SER+. SER+ may be more common than we originally thought, as some SER+ is found in all oocytes. Although SER+ positively affected oocyte maturation rate, it did not affect births. We hypothesized that this is because the best embryos are chosen at every step of the process, and the oocytes with the poorest characteristics are removed. We therefore suggest a standard method for measuring SER+. Although embryos produced from SER+ cycles can be used, they should only be transferred when no other suitable embryos are available over several cycles.

Is it time to reconsider how to manage oocytes affected by smooth endoplasmic reticulum aggregates?

STUDY QUESTION

Did the revised Alpha/ESHRE consensus (Vienna, 2017) bring a real answer on managing oocytes with aggregates of smooth endoplasmic reticulum (SERa)?

SUMMARY ANSWER

According to the currently available literature, a case by case approach on the time of injecting/inseminating SERa+ oocytes may be not helpful for embryologists making a decision, so we suggest fertilizing both SERa+ and SERa- oocytes and prioritizing embryos derived from SERa- oocytes.

WHAT IS KNOWN ALREADY?

In 2011, the Istanbul consensus recommended not to inject/inseminate SER+ oocytes due to adverse foetal outcomes reported in literature. At the end of 2017, a panel of experts reconsidered this recommendation and advised a case by case approach. Hence, with a lack of clear recommendations, in-vitro fertilization practitioners still have heterogeneous attitudes when managing SERa+ oocytes. In this context of controversy, an updated review could be helpful in (i) forming a common language for managing cases of SERa+ oocytes and (ii) offering the most ethical practice and best care for patients seeking infertility treatment or fertility preservation.

STUDY DESIGN, SIZE, DURATION

This review (with a last literature search on 1 June 2018) evaluated the effect of the SER dysmorphism on embryological and neonatal outcomes.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Studies were considered for inclusion if they were prospective or retrospective cohort or case-control studies. Electronic searches of the Pubmed and Embase databases were done using the keyword combination: smooth endoplasmic reticulum, SER, oocyte and zygote. Abstracts and articles written in English and limited to humans were included.

MAIN RESULTS AND THE ROLE OF CHANCE

The search returned a total of 726 studies among which 21 met the inclusion criteria. The literature does not unanimously support a negative association between SERa and embryogenesis, implantation or assisted reproductive therapy outcomes. The reviewed studies reported 112 neonatal outcomes after transfers where at least one embryo originated from oocyte affected by SERa. They included 101 healthy babies, three live births with malformations, three neonatal deaths, one stillbirth and four medical interruptions of pregnancy. After transfer of embryos exclusively derived from SERa+ oocytes, a total of 48 healthy newborns were reported along with four babies with perinatal complications (including one ventricular septal defect), one stillbirth, one neonatal death and one pregnancy termination for multiple malformations.

LIMITATIONS, REASONS FOR CAUTION

As with any review, this review was limited by the quality of the included studies especially in terms of possible methodological limitations, the limited sample size and the retrospective aspect of the studies. Among the 21 selected studies, seven were abstracts and two were case reports. Of the remaining 14 studies, only three were prospective. The tools used in identifying SERa+ oocytes may have varied from one study to another and a consequent misclassification cannot be excluded. Considering the poor resolution of light microscopy in detecting SER aggregates, we are not sure that apparently SERa- oocytes do not really exhibit such a dysmorphism if they were analysed under electronic microscopy or a time lapse system.

WIDER IMPLICATIONS OF THE FINDINGS

In the light of the existing data and the lack of a real link between fertilizing SERa+ oocytes and the occurrence of embryo aneuploidy/malformations, we think that discarding SERa+ oocytes may be not the most ethical approach even in patients with large cohorts on the day of oocyte retrieval. Avoiding the wastage of oocytes and embryos with respect to medical ethics remains a constant concern in daily IVF practice. Thus, we recommend that all mature oocytes could be fertilized and embryos originating from SERa- oocytes would be preferably transferred, even if they come from a cohort with SERa+ oocytes. The remaining embryos derived from SERa+ oocytes could be considered with a lower priority for transfer after obtaining consent from the couple if a strict follow-up of the pregnancy and the baby is performed.

STUDY FUNDING/COMPETING INTEREST(S)

We have no conflict of interest to declare and no funding was received.

REGISTRATION NUMBER

N/A.

The impact of letrozole administration on oocyte morphology in breast cancer patients undergoing fertility preservation

Objective:

Patients submitted to oncological fertility preservation with letrozole and gonadotropins seem to present a higher rate of immature oocytes and lower fertilization rates in comparison to infertile patients submitted to IVF cycles with gonadotropins. The aim of this study was to evaluate the influence of letrozole on oocyte morphology in patients with breast cancer submitted to fertility preservation.

Methods:

Retrospective analysis performed at a public tertiary hospital in São Paulo, Brazil. The oocytes were retrieved from patients with breast cancer undergoing fertility preservation (n=69), and from infertile women undergoing in vitro fertilization (n=92). We evaluated 750 oocytes obtained from breast cancer patients submitted to ovarian stimulation with letrozole and gonadotropins, and 699 oocytes from patients without breast cancer submitted to ovarian stimulation for in vitro fertilization with gonadotropins only due to male factor infertility. The mature oocytes retrieved were analyzed for the presence of refractile bodies, ooplasm color and regularity, central granulation degree, cortical granules, zona pellucida staining and regularity, perivitelline space, presence of vacuoles or abnormal smooth-surfaced endoplasmic reticle and oocyte retraction.

Results:

There was a higher incidence of alterations in oocyte morphology in the letrozole group when compared to the control group: increased perivitelline space (p=0.007), irregular zona pellucida (p<0.001), refractile bodies (p<0.001), dark ooplasm (p<0.001), granular ooplasm (p<0.001), irregular ooplasm (p<0.001) and dense central granulation (p<0.001).

Conclusion:

Letrozole is a risk factor for worse oocyte morphology. However, the clinical impact of ovarian stimulation protocol with combined use of gonadotropins and letrozole for fertility preservation remains unclear in this setting. These data underline the importance of establishing the predictive potential of morphological dimorphisms of human oocytes in IVF outcomes.

Ovarian response to stimulation and suboptimal endometrial development are associated with adverse perinatal outcomes in intracytoplasmic sperm injection cycles

Objective:

To study which factors affect perinatal outcomes in intracytoplasmic sperm injection (ICSI) cycles.

Methods:

Data was obtained from 402 live births born to 307 patients undergoing ICSI cycles in a private university-affiliated IVF center between Jan/2014 and Dec/2015. The influences of the cycles' characteristics on the number of gestational weeks to livebirth (GW), baby birth weight (BW), and baby birth length (BL) were evaluated by linear regression models, adjusted for maternal age and body mass index, number of transferred embryos, number of gestational sacs, and number of born infants. In a subsequent analysis, GW, BW and baby sex were utilized for cycle classification into the groups Appropriate for gestational age (AGA n=256) and Small for gestational age (SGA n=146), which were compared by general linear models adjusted for the same confounder variables.

Results:

The number of follicles (β=-0.069 p=0.018) and retrieved oocytes (β=-0.087 p=0.049) were negatively correlated with BL. The endometrial thickness was positively correlated with GW (β=0.198 p=0.003) and BW (β=28.351 p=0.044). When each baby was classified into AGA and SGA groups, it was observed that SGA babies were derived from cycles with higher estradiol levels at hCG day (SGA: 3897.01±550.35 vs. AGA: 2324.78±101.86 p=0.006) and higher number of retrieved oocytes (SGA: 16.70±1.78 vs. AGA: 12.92±0.42 p=0.042). The endometrial thickness was significantly lower in the SGA group (SGA: 10.2±0.23 vs. AGA: 11.68±0.17 vs. p=0.029).

Conclusion:

Higher ovarian response to stimulation and suboptimal endometrial development are associated with adverse perinatal outcomes in ICSI cycles.

Live Birth Rates in In vitro Fertilization Cycles with Oocytes Containing Smooth Endoplasmic Reticulum Aggregates and Normal Oocytes

Aims:

The aims of this study were to compare the live birth, embryological and pregnancy outcomes after intracytoplasmic sperm injection (ICSI) in patients who have oocytes with smooth endoplasmic reticulum aggregates (SERa+ cycles) and patients with normal oocytes and to compare the pregnancy outcomes based on the observed frequency of SERa.

Settings and Design:

The current study was a retrospective case record review of patients undergoing ICSI from 2012 to 2016 in a specialty fertility center.

Materials and Methods:

The patients were divided into two groups based on the presence of SERa: patients with at least one oocyte containing SERa (SERa+ cycles) (n = 112) and patients with normal oocytes (n = 839). The primary outcome measure was live birth rate. The secondary outcome measures were fertilization rate, cleavage rate, blastocyst formation rate, clinical pregnancy rate, miscarriage rate, and anomalies in children born.

Results:

Women with SERa+ cycles showed similar live birth rates, fertilization rates, cleavage rates, blastocyst formation rates, clinical pregnancy rates, miscarriage rates, and abnormalities in children compared to women with normal oocytes. A gradual reduction in live birth rates was observed when the percentage of oocytes containing SERa increased. The group containing >50% of oocytes with SERa demonstrated no live births.

Conclusions:

Presence of SERa had no major overall negative impact on key embryological and live birth outcomes. A reduction in the live birth rate with increasing proportion of SERa oocytes was observed, with no live births in the group with >50% or all affected oocytes.

Complex chromosomal aberrations in a fetus originating from oocytes with smooth endoplasmic reticulum (SER) aggregates

The presence of smooth endoplasmic reticulum aggregates (SERa) in the ooplasm is considered as the most severe oocyte dysmorphism due to its serious and potentially lethal outcomes in offspring. In the present case report, a couple underwent their first intracytoplasmic sperm injection (ICSI) cycle using a gonadotrophin releasing hormone (GnRH) antagonist protocol, followed by fetal ultrasound scanning and amniocentesis. SERa were observed in all oocytes retrieved. A singleton pregnancy was established. The second trimester fetal ultrasound scan revealed a female fetus with overlapping fingers in both hands, and amniocentesis was performed for the detection of chromosomal abnormalities. Comprehensive genetic analysis with the combined use of array-comparative genomic hybridization (CGH), fluoresence in situ hybridization (FISH) and conventional cytogenetics revealed a complex chromosome rearrangement (CCR) involving three break points on two chromosomes, resulting in a reciprocal translocation with a cryptic 2q31 deletion. A week following amniocentesis, there was rupture of amniotic membranes and a stillborn was delivered. This is the first case in the literature to report a CCR with concomitant 2q31 deletion resulting in a well-defined and clinically recognizable contiguous gene syndrome with an abnormal phenotype in a fetus arising from a cohort of oocytes affected by SERa. It is suggested that fertilization and transfer of oocytes with SERa should be avoided, until further research establishes whether there is a causal relationship between the presence of SERa and chromosomal abnormalities in the resulting fetus.

ABBREVIATIONS

SER: smooth endoplasmic reticulum; ICSI: intracytoplasmic sperm injection; GnRH: gonadotrophin releasing hormone; CGH: comparative genomic hybridization; FISH: fluoresence in situ hybridization; FSH: follicle stimulating hormone; hCG: human chorionic gonadotrophin; OHSS: ovarian hyperstimulation syndrome; IVF: in vitro fertilization; MII: metaphase II; GV: germinal vesicle; CCR: complex chromosome rearrangement.

Enantioselective Bioaccumulation and Toxicity of the Neonicotinoid Insecticide Dinotefuran in Earthworms ( Eisenia fetida)

The enantioselective bioaccumulation and toxicity of dinotefuran in earthworms were studied in this study. The results showed that S-dinotefuran accumulated faster than Rac-dinotefuran and R-dinotefuran in earthworms. The acute toxicity of S-dinotefuran was 1.49 and 2.67 times that of the Rac-dinotefuran and R-dinotefuran in artificial soil during 14 days of exposure. At 1.0 mg/kg, the three tested chemicals inhibited the growth and reproduction as well as induced oxidative stress effects in earthworms; however, the toxic effects induced by S-dinotefuran were the most serious. The transcriptome sequencing results showed that S-dinotefuran had stronger interactions to biomacromolecules and influences on the endoplasmic reticulum (ER) than R-dinotefuran, which may be the main reason for enantioselectivities between the two enantiomers. The present results indicated that the risk of S-dinotefuran was higher than that of Rac-dinotefuran and R-dinotefuran in the soil environment to earthworms. Risk assessment of dinotefuran should be evaluated at the enantiomer level.

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.

Oocytes with smooth endoplasmic reticulum clusters originate blastocysts with impaired implantation potential

OBJECTIVE

To study whether embryos derived from oocytes presenting a smooth endoplasmic reticulum cluster (SERC) are less likely to develop into blastocysts and implant.

DESIGN

Transversal study.

SETTING

Private university-affiliated in vitro fertilization (IVF) center.

PATIENT(S)

Total of 7,609 oocytes obtained from 743 intracytoplasmic sperm injection (ICSI) cycles.

INTERVENTION(S)

Oocytes split between the SERC-positive cycles (with at least one SERC-positive oocyte) and the SERC-negative cycles (only oocytes free of SERC).

MAIN OUTCOME MEASURE(S)

Embryo implantation.

RESULT(S)

A statistically significantly higher mean number of follicles (24.0 ± 10.5 vs. 19.6 ± 10.5), retrieved oocytes (17.8 ± 8.3 vs. 14.3 ± 8.0), and mature oocytes (13.5 ± 6.2 vs. 10.6 ± 5.9) were observed in the SERC-positive cycles as compared with SERC-negative cycles. The implantation rate was statistically significantly lower in SERC-positive cycles as compared with SERC-negative cycles (14.8% vs. 25.6%; odds ratio 0.61; 95% confidence interval, 0.44-0.86). When only cycles with in which none (0) or all the blastocysts transferred had implanted (100%) were analyzed, the mean implantation rate per transferred blastocyst in the SERC-negative group was 20.5%; no blastocysts derived from SERC-positive oocytes implanted.

CONCLUSION(S)

The occurrence of SERC impairs embryo implantation. Careful oocyte observation that takes into account the presence of SERC should be part of embryo selection strategy before transfer.

Ultrastructural and cytogenetic analyses of mature human oocyte dysmorphisms with respect to clinical outcomes

PURPOSE

The study aimed to describe the ultrastructure of two human mature oocyte intracytoplasmic dysmorphisms, the bull-eye inclusion and the granular vacuole, with evaluation of clinical outcomes after intracytoplasmic sperm injection (ICSI) treatment.

METHODS

We retrospectively evaluated 4099 consecutive ICSI cycles during the period 2003-2013. Three groups were compared: controls, those with a bulls-eye inclusion, and those with granular vacuoles. Oocyte dysmorphisms were evaluated by transmission electron microscopy and in situ fluorescence hybridization (FISH). Detailed data on demographic and stimulation characteristics, as well as on embryological, clinical, and newborn outcomes, are fully presented.

RESULTS

The bull-eye inclusion is a prominent smooth round structure containing trapped vesicles, being surrounded by lipid droplets. The presence of this dysmorphism in the oocyte cohort had no clinical impact except when transferred embryos were exclusively derived from dysmorphism oocytes. The granular vacuole is delimited by a discontinuous double membrane and contains lipid droplets and vesicles. As FISH analysis revealed the presence of chromosomes, they probably represent pyknotic nuclei. The presence of this dysmorphism in the oocyte cohort had no clinical impact except when at least one transferred embryo was derived from dimorphic oocytes.

CONCLUSIONS

Poor clinical outcomes were observed with transfer of embryos derived from dysmorphism oocytes, although without causing gestation or newborn problems. The bull-eye inclusion and granular vacuoles may thus be new prognostic factors for clinical outcomes.

Oocytes affected by smooth endoplasmic reticulum aggregates: to discard or not to discard?

PURPOSE

Oocytes containing smooth endoplasmic reticulum aggregates (SERa) have been associated with reduced fertilization and clinical pregnancy rates as well as compromised neonatal outcomes. It was therefore recommended by an Alpha-ESHRE Consensus to discard oocytes presenting this dysmorphism. The data in the literature are nevertheless conflicting and healthy babies have recently been obtained from affected oocytes. The objectives of this study were to compare clinical outcomes between ICSI cycles with and without oocytes affected by smooth endoplasmic reticulum aggregates and to confirm whether affected oocytes can produce healthy babies.

METHODS

A prospective observational study was performed comparing 714 SERa- ICSI cycles to 112 SERa+ cycles. Among the SERa+ cycles, 518 SERa- oocytes and 213 SERa+ oocytes were analyzed. Fertilization, embryo quality, and pregnancy rates as well as neonatal outcomes were compared between SERa+ and SERa- cycles as well as between SERa+ and SERa- oocytes.

RESULTS

The presence of SERa was not associated with an adverse effect on embryological, clinical or neonatal data for SERa+ cycles and oocytes. Seven healthy babies were born from embryos originating from SERa+ oocytes.

CONCLUSIONS

These results are encouraging and might contribute in the future to a revision of the Alpha-ESHRE Consensus. Larger studies, including a correlation between frequency and size of SERa, clinical outcomes and malformation rates, as well as the follow-up of babies born are nevertheless necessary. In the meantime, the currently conflicting data requires caution when considering transfers of embryos affected by SERa.

The impact of Alpha/ESHRE consensus regarding oocytes with aggregates of smooth endoplasmic reticulum (SERa) on in vitro fertilization outcome

PURPOSE

The present study aimed to gather information on the impact of Alpha/European Society of Human Reproduction and Embryology (ESHRE) consensus regarding oocytes with aggregates of smooth endoplasmic reticulum (SERa) on in vitro fertilization outcome. In particular, we investigated if patients undergoing intracytoplasmic sperm injection (ICSI) and whose oocytes are discarded due to SERa have a higher chance of embryo transfer cancellation compared to patients without SERa oocytes.

METHODS

This is a nested case-control study drawn from the cohort of women referring for in vitro fertilization with ICSI. Cases were patients showing at least one oocyte with SERa at the time of injection. Controls were subsequent patients showing no SERa oocytes and matched ratio 1:1 for age, clinical indication to in vitro fertilization (IVF), and body mass index. The main outcome was the rate of embryo transfer cancellation.

RESULTS

The percentage of women experiencing a transfer cancellation (absence of suitable oocytes or viable embryos) in their ICSI cycle were significantly higher in cases (18 %) compared to controls (8 %) (p = 0.02); however, adjusted odds ratio for FSH and number of SERa oocytes, of follicles, of retrieved oocytes, and of inseminated oocytes were not statistically significant.

CONCLUSIONS

We have shown that the exclusion of SERa oocytes from ICSI cycles causes an increased frequency of transfer cancellation. This effect is mostly due to the reduced number of available oocytes after exclusion of SERa oocytes.

Effect of oocyte dysmorphisms on intracytoplasmic sperm injection cycle outcomes in normal ovarian responders

AIM

The aim of this study was to identify the influence of oocyte dysmorphisms on clinical outcomes after intracytoplasmic sperm injection cycle in normal responders.

MATERIAL AND METHODS

In the prospective study, morphology of 1999 metaphase II oocytes retrieved from 316 intracytoplasmic sperm injection cycles was evaluated from March 2011 to March 2013 at Royan Institute. Controlled ovarian stimulation was performed by long standard agonist protocol. Oocyte morphology was assessed before sperm injection by one embryologist. The associations between fertilization rate, embryo quality and the independent variables were analyzed using odds ratio (OR) calculated with unconditional logistic regression test.

RESULTS

From all retrieved oocytes, 1543 (77.1%) showed at least one morphologic aberration. Presence of cytoplasmic vacuoles and high cytoplasmic viscosity were associated with a significant decrease in the fertilization rate (OR: 0.5; P = 0.004 and OR: 0.6; P = 0.03, respectively). The results showed that oocyte morphology did not affect embryo quality. The number of gonadotrophin injections used showed a direct relation with presence of large perivitelline space. No significant difference was observed among four groups (women with total normal morphologic oocytes [group 1], women with total extracytoplasmic dysmorphic oocytes [group 2], women with total cytoplasmic dysmorphic oocytes [group 3] and women with total oocytes containing multiple dysmorphic features [group 4]) in terms of implantation and clinical pregnancy rates.

CONCLUSIONS

Metaphase II oocyte morphology had minor impacts on fertilization rate, pronuclear morphology and embryo quality in women with normal ovarian response.

Policy of IVF centres towards oocytes affected by Smooth Endoplasmic Reticulum aggregates: a multicentre survey study

PURPOSE

The presence of Smooth Endoplasmic Reticulum aggregates (SERa) has been reported to be associated with adverse outcomes. An Alpha-ESHRE Consensus was published in 2011, strongly recommending to not inseminating affected oocytes. On the other hand, healthy babies have been born from oocytes presenting this dysmorphism. We surveyed several European IVF centres, to assess their attitudes concerning affected oocytes.

METHODS

This survey is based on a computer format and includes questions regarding the fate of affected oocytes.

RESULTS

About 14 % of centres who answered our survey discard SERa+ oocytes. 43 % of centres that do not discard the oocytes, register and follow up neonatal data. About a quarter of centres inform their patients about this dysmorphism. Half of them require an informed consent prior to transferring affected embryos. Twenty-one centres reported having SERa+ births, with one reporting a malformation. 48 % of centres declared having been influenced by the Alpha-ESHRE Consensus, in their management policy of SERa+ oocytes.

CONCLUSIONS

Few centres scrupulously respect the recommendations of the Alpha-ESHRE Consensus and discard affected oocytes. Since it is essential to determine if there truly is an impact of this dysmorphism and whether the guidelines are still valid, transfer of affected embryos should only be done when accompanied with data recording and monitoring of all foetal malformations from IVF. Clarifying the situation will allow IVF centres to correctly inform patients about the risk of birth malformations as well as whether a decreased chance of pregnancy exists.

Oocyte maturation: gamete-somatic cells interactions, meiotic resumption, cytoskeletal dynamics and cytoplasmic reorganization

BACKGROUND

In a growth phase occurring during most of folliculogenesis, the oocyte produces and accumulates molecules and organelles that are fundamental for the development of the preimplantation embryo. At ovulation, growth is followed by a phase of maturation that, although confined within a short temporal window, encompasses modifications of the oocyte chromosome complement and rearrangements of cytoplasmic components that are crucial for the achievement of developmental competence. Cumulus cells (CCs) are central to the process of maturation, providing the oocyte with metabolic support and regulatory cues.

METHODS

PubMed was used to search the MEDLINE database for peer-reviewed original articles and reviews concerning oocyte maturation in mammals. Searches were performed adopting 'oocyte' and 'maturation' as main terms, in association with other keywords expressing concepts relevant to the subject. The most relevant publications, i.e. those concerning major phenomena occurring during oocyte maturation in established experimental models and the human species, were assessed and discussed critically to offer a comprehensive description of the process of oocyte maturation.

RESULTS

By applying the above described search criteria, 6165 publications were identified, of which 543 were review articles. The number of publications increased steadily from 1974 (n = 7) to 2013 (n = 293). In 2014, from January to the time of submission of this manuscript, 140 original manuscripts and reviews were published. The studies selected for this review extend previous knowledge and shed new and astounding knowledge on oocyte maturation. It has long been known that resumption of meiosis and progression to the metaphase II stage is intrinsic to oocyte maturation, but novel findings have revealed that specific chromatin configurations are indicative of a propensity of the oocyte to resume the meiotic process and acquire developmental competence. Recently, genetic integrity has also been characterized as a factor with important implications for oocyte maturation and quality. Changes occurring in the cytoplasmic compartment are equally fundamental. Microtubules, actin filaments and chromatin not only interact to finalize chromosome segregation, but also crucially co-operate to establish cell asymmetry. This allows polar body extrusion to be accomplished with minimal loss of cytoplasm. The cytoskeleton also orchestrates the rearrangement of organelles in preparation for fertilization. For example, during maturation the distribution of the endoplasmic reticulum undergoes major modifications guided by microtubules and microfilaments to make the oocyte more competent in the generation of intracellular Ca(2+) oscillations that are pivotal for triggering egg activation. Cumulus cells are inherent to the process of oocyte maturation, emitting regulatory signals via direct cell-to-cell contacts and paracrine factors. In addition to nurturing the oocyte with key metabolites, CCs regulate meiotic resumption and modulate the function of the oocyte cytoskeleton.

CONCLUSIONS

Although the importance of oocyte maturation for the achievement of female meiosis has long been recognized, until recently much less was known of the significance of this process in relation to other fundamental developmental events. Studies on chromatin dynamics and integrity have extended our understanding of female meiosis. Concomitantly, cytoskeletal and organelle changes and the ancillary role of CCs have been better appreciated. This is expected to inspire novel concepts and advances in assisted reproduction technologies, such as the development of novel in vitro maturation systems and the identification of biomarkers of oocyte quality.

Oocyte environment: follicular fluid and cumulus cells are critical for oocyte health

Bidirectional somatic cell-oocyte signaling is essential to create a changing intrafollicular microenvironment that controls primordial follicle growth into a cohort of growing follicles, from which one antral follicle is selected to ovulate a healthy oocyte. Such intercellular communications allow the oocyte to determine its own fate by influencing the intrafollicular microenvironment, which in turn provides the necessary cellular functions for oocyte developmental competence, which is defined as the ability of the oocyte to complete meiosis and undergo fertilization, embryogenesis, and term development. These coordinated somatic cell-oocyte interactions attempt to balance cellular metabolism with energy requirements during folliculogenesis, including changing energy utilization during meiotic resumption. If these cellular mechanisms are perturbed by metabolic disease and/or maternal aging, molecular damage of the oocyte can alter macromolecules, induce mitochondrial mutations, and reduce adenosine triphosphate production, all of which can harm the oocyte. Recent technologies are now exploring transcriptional, translational, and post-translational events within the human follicle with the goal of identifying biomarkers that reliably predict oocyte quality in the clinical setting.

Deliveries of babies with normal health derived from oocytes with smooth endoplasmic reticulum clusters

PURPOSE

To examine the impact on development of derived embryos from smooth endoplasmic reticulum clusters (SERC) in human metaphase II (MII) oocytes.

METHODS

Retrospective analysis at Kyono ART Clinic. Comparison of embryological development, pregnancy, live birth and fetal malformation between oocytes with SERC (the SERC(+) group) and those without (the SERC(-) group) in 2,158 patients (3,758 cycles) after ICSI.

RESULTS

Fertilization and implantation rate were significantly lower in SERC(+) MII oocytes than in SERC(-) MII oocytes. After the transfer of fresh and vitrified embryos derived from SERC(+) oocytes, 14 pregnancies resulted in 14 healthy babies, including 2 from fresh embryo transfer (ET) and 12 from vitrified-warmed ET, with no malformations.

CONCLUSION(S)

The presence of SERC in MII oocytes was associated with significantly lower fertilization rates and implantation rates than seen in SERC(-) MII oocytes within SERC (+) cycles. However, SERC had no impact on post-implantation development as well as neonatal outcome.