Safety of early cumulus cell removal combined with early rescue ICSI in the prevention of fertilization failure.

RESEARCH QUESTION: What are the clinical outcomes and safety implications of early cumulus cell removal after short-term insemination combined with early rescue intracytoplasmic sperm injection (ICSI) in preventing fertilization failure? DESIGN: In this retrospective study, a total of 14,360 cycles were divided into four groups based on insemination method and fertilization ability: conventional IVF group (n = 5519); early cumulus cell removal group (n = 4107); conventional ICSI group (n = 4215); and early rescue ICSI group (where failed or low fertilization was predicted, n = 519). Fertilization outcomes, pregnancy outcomes, neonatal outcomes and birth defects were analysed by comparing the early cumulus cell removal group with the conventional IVF group, and the early rescue ICSI group with the conventional ICSI group. RESULTS: There were no significant differences in the outcomes of fertilization, pregnancy, neonates or birth defects between the conventional IVF group and the early cumulus cell removal group (P > 0.05). When compared with the conventional ICSI group, the early rescue ICSI group had similar rates of two pronuclei (2PN) at fertilization, clinical pregnancy, miscarriage, ectopic pregnancy, live birth, sex, mean gestational age, very low birthweight, macrosomia and birth defects (P > 0.05) but a higher polyploidy rate, lower high-quality embryo rate (both P < 0.001), lower twin pregnancy rate (P < 0.01), lower rate of low birthweight, and a higher rate of normal birthweight (both P = 0.024). CONCLUSIONS: Early cumulus cell removal combined with early rescue ICSI led to good pregnancy and neonatal outcomes without an increase in birth defects. This approach could therefore be an effective and safe method for patients with fertilization failure in conventional IVF.

Biallelic variants in MAD2L1BP (p31comet) cause female infertility characterized by oocyte maturation arrest.

Human oocyte maturation arrest represents one of the severe conditions for female patients with primary infertility. However, the genetic factors underlying this human disease remain largely unknown. The spindle assembly checkpoint (SAC) is an intricate surveillance mechanism that ensures accurate segregation of chromosomes throughout cell cycles. Once the kinetochores of chromosomes are correctly attached to bipolar spindles and the SAC is satisfied, the MAD2L1BP, best known as p31comet, binds mitosis arrest deficient 2 (MAD2) and recruits the AAA+-ATPase TRIP13 to disassemble the mitotic checkpoint complex (MCC), leading to the cell-cycle progression. In this study, by whole-exome sequencing (WES), we identified homozygous and compound heterozygous MAD2L1BP variants in three families with female patients diagnosed with primary infertility owing to oocyte metaphase I (MI) arrest. Functional studies revealed that the protein variants resulting from the C-terminal truncation of MAD2L1BP lost their binding ability to MAD2. cRNA microinjection of full-length or truncated MAD2L1BP uncovered their discordant roles in driving the extrusion of polar body 1 (PB1) in mouse oocytes. Furthermore, the patient's oocytes carrying the mutated MAD2L1BP resumed polar body extrusion (PBE) when rescued by microinjection of full-length MAD2L1BP cRNAs. Together, our studies identified and characterized novel biallelic variants in MAD2L1BP responsible for human oocyte maturation arrest at MI, and thus prompted new therapeutic avenues for curing female primary infertility.

Anti-Ro/SSA and/or anti-La/SSB antibodies are associated with adverse endometrial status.

PROBLEM: Anti-Ro/SSA and/or anti-La/SSB (anti-SSA/SSB) antibodies impair pregnancy outcomes, including embryo implantation and pregnancy maintenance. Optimal endometrial immune status is essential for successful pregnancy. However, whether these antibodies affect endometrial immune status is still unclear. Menstrual blood can be collected non-invasively, differs from peripheral blood, and can reflect the endometrial immune status. We herein focused on changes in subsets of natural killer (NK) cells and T cells in menstrual blood. METHODS OF STUDY: Menstrual blood samples from anti-SSA/SSB antibody-positive (n = 18) and anti-SSA/SSB antibody-negative control (n = 8) women were collected, and the profile of lymphocyte subsets was analyzed. The phenotypes of menstrual blood CD49a- and CD49a+ NK cells were compared, and the abundance of NK and CD49a+ NK cells in menstrual blood of the two groups was assessed. Additionally, CD4+T and CD8+T cells were investigated for their ability to secret functional cytokines. RESULTS: Menstrual blood contains a large number of (mostly CD49a+) NK cells, which exhibited a more exhausted phenotype with greater expression of the immune checkpoint molecules programmed cell death protein 1 and Tim-3 compared to CD49a- conventional NK cells. CD8+T cells in menstrual blood from anti-SSA/SSB antibody-positive women produced a stronger response after stimulation, accompanied by increased interferon-γ, tumor necrosis factor-α, and granzyme B secretion (P < 0.05, separately). CONCLUSION: Menstrual blood cell composition differs between anti-SSA/SSB antibody-positive women and normal controls, especially in terms of CD49a+ NK cells and CD8+T cells, unbalancing the immune cell composition and inflammatory uterine microenvironment and possibly contributing to adverse pregnancy outcomes.

Effect of weight loss on pregnancy outcomes, neuronal-reproductive-metabolic hormones and gene expression profiles in granulosa cells in obese infertile PCOS patients undergoing IVF-ET.

Objective: To investigate the effect of weight loss on pregnancy outcomes, PCOS related neuronal-reproductive-metabolic hormones and ovarian granulosa cell gene expression profiles in obese PCOS infertile patients undergoing in vitro fertilization-embryo transfer (IVF-ET). Methods: 75 patients undergoing IVF-ET due to tubal factors alone collected as the control group (group A), and 352 patients with obese PCOS infertility were divided into four groups according to the amount of weight loss before IVF: 0 kg (group B), 1-5 kg (group C), 5-10 kg (group D), and >10 kg (group E). Six cases of ovarian granulosa cells were collected randomly with the random number table method in each group for detecting mRNA profiling. Pathway networks and biological functions of the differentially expressed genes were analyzed. Validation by RT-PCR was performed. Results: (1) The levels of luteinizing hormone(LH), testosterone(T) and homeostasis model assessment insulin resistance(HOMA-IR) in group E were significantly lower than those in groups B and C (P<0.05). (2) Compared with groups A and E, groups B and C showed increased total gonadotropin (Gn) and days of Gn stimulation (P<0.05), and the E2 level on trigger day and number of oocytes obtained in group B was significantly less than that in group E (P<0.05 or 0.01). Embryo implantation rate, clinical pregnancy rate and live birth rate were increased and miscarriage rate was decreased in groups A, D and E compared with group B (P<0.05 or 0.01). (3) There were significant differences among the control group and PCOS groups in some genes that are involved in neuronal-reproductive-metabolic endocrine, transcriptional regulation, cell proliferation and differentiation, etc (P<0.05). RNA-Seq results were validated by real time PCR analysis for the expression of follicle stimulating hormone receptor (FSHR), drosophila mothers against decapentaplegic protein 7(Smad7) and glutathione peroxidase 3(GPX3) genes that are known to have an important role in follicular development. Functional alterations were confirmed by the improvement in the ovarian responsiveness to Gn and embryo quality. Conclusion: Weight loss more than 5kg may regulate the neuroreproductive endocrine hormone secretion, insulin resistance and gene expression profiles of ovarian granulosa cells, so as to improve the ovarian responsiveness to Gn, the embryo quality, embryo implantation rate, clinical pregnancy rate, live birth rate, and reduce the spontaneous abortion rate in obese infertile PCOS patients undergoing IVF-ET. Clinical trial registration: www.chictr.org.cn, identifier ChiCTR1800018298.

Cyanidin-3-Ο-glucoside supplementation in cryopreservation medium improves human sperm quality.

Currently, the cryopreservation of human spermatozoa must overcome the adverse effects of excessive oxidation. In this study, we aimed to evaluate the effect of supplementation of cryopreservation medium with cyanidin-3-Ο-glucoside (C3G) on sperm quality. Semen samples were obtained from men with normozoospermia according to WHO criteria (n = 39). The sperm parameter values were compared after cryopreservation in medium supplemented with and without C3G.Compared with the control group (without additive), low doses (50 µM and 100 µM) of C3G improved sperm viability and motility and decreased the reactive oxygen species (ROS) of spermatozoa, while high doses (200 µM) of C3G did not obviously enhance sperm quality. The amount of DNA fragmentation index (DFI) and high DNA stainability (HDS) after freezing were higher in the control group than in the C3G supplementation groups. Low-concentration C3G supplementation (50 µM) was negatively correlated with sperm ROS levels (r = -0.2, p = 0.03). Collectively, our findings suggest that C3G could be an efficient semen cryoprotectant that ameliorates oxidative stress in human sperm during cryopreservation.

Novel mutations in NLRP5 and PATL2 cause female infertility characterized by primarily oocyte maturation abnormality and consequent early embryonic arrest.

PURPOSE: This study aims to identify the genetic causes of 12 women with primary infertility characterized by primarily oocyte maturation abnormality and consequent early embryonic arrest. METHODS: Genomic DNA was isolated from peripheral blood samples. Whole-exome sequencing was performed on the probands, and the identified variants were confirmed by Sanger sequencing. The pathogenicity of the identified variants on the protein was accessed in silico. And we used qRT-PCR to detect the possible effects of the novel mutation on the mRNA level of NLRP5. RESULTS: A novel homozygous frameshift variant (p.V429Efs*30) in NLRP5 and compound heterozygous variants with a novel frameshift variant (p.A297Efs*20) and a recurrent variant (c. 223-14_223-2delCCCTCCTGTTCCA) in PATL2 were identified in two unrelated affected individuals. qRT-PCR showed an obvious decrease of the mutant NLRP5 mRNA. In addition, the truncated proteins of NLRP5 and PATL2 were predicted to be non-functional due to the deletion of the most or the whole region of the critical functional domain(s) respectively. CONCLUSIONS: This study identified novel mutations in NLRP5 and PATL2, further expanding the mutational and phenotypic spectrum of both genes. This is the first report of the NLRP5 mutations that associates with oocyte maturation abnormality in humans.

A Simple and Efficient Method to Cryopreserve Human Ejaculated and Testicular Spermatozoa in -80°C Freezer.

Human autologous sperm freezing involves ejaculated sperm, and testicular or epididymal puncture sperm freezing, and autologous sperm freezing is widely used in assisted reproductive technology. In previous studies, researchers have tried to cryopreserve sperm from mammals (rats, dogs, etc.) using a -80°C freezer and have achieved success. It is common to use liquid nitrogen vapor rapid freezing to cryopreserve human autologous sperm. However, the operation of this cooling method is complicated, and the temperature drop is unstable. In this study, we compared the quality of human ejaculation and testicular sperm after liquid nitrogen vapor rapid freezing and -80°C freezing for the first time. By analyzing sperm quality parameters of 93 ejaculated sperm and 10 testicular sperm after liquid nitrogen vapor rapid freezing and -80°C freezing, we found reactive oxygen species (ROS) of sperm of the -80°C freezer was significantly lower than liquid nitrogen vapor rapid freezing. Regression analysis showed that progressive motility, ROS, and DNA fragmentation index (DFI) in post-thaw spermatozoa were correlated with sperm progressive motility, ROS, and DFI before freezing. For the freezing method, the -80°C freezer was positively correlated with the sperm progressive motility. Among the factors of freezing time, long-term freezing was negatively correlated with sperm progressive motility and ROS. Although freezing directly at -80°C freezer had a slower temperature drop than liquid nitrogen vapor rapid freezing over the same period, the curves of the temperature drop were similar, and slight differences in the freezing point were observed. Furthermore, there were no statistically significant differences between the two methods for freezing testicular sperm. The method of direct -80°C freezing could be considered a simplified alternative to vapor freezing for short-term human sperm storage. It could be used for cryopreservation of autologous sperm (especially testicular sperm) by in vitro fertilization centers. Clinical Trial Registration: (website), identifier (ChiCTR2100050190).

Compound heterozygosity for novel AURKC mutations in an infertile man with macrozoospermia.

Among causes of infertility, teratozoospermia is characterised by a percentage of morphologically abnormal spermatozoa >4%. Macrozoospermia, one form of monomorphic teratozoospermia, is observed in <1% of cases of male infertility and is described as approximately 100% large-headed and/or multitailed spermatozoa. This study reports that an infertile man with large-head spermatozoa presenting compound heterozygosity aurora kinase C (AURKC) mutations (c.382C>T, c.572C>T) by whole-exome sequencing. Consequently, both two novel AURKC mutations had high probability of damage-causing and conserved across species and extremely low allele frequency in the population. Flow cytometry analysis revealed a high ratio of sperm DNA fragmentation. Two intracytoplasmic sperm injection (ICSI) procedures were attempted for the patient, but all were unsuccessful. These results indicate that sequence analysis should be performed for the variants of AURKC in Chinese patients with macrozoospermia.

Novel mutations in PATL2 cause female infertility with oocyte germinal vesicle arrest.

STUDY QUESTION: Do PATL2 mutations account for female infertility with oocyte germinal vesicle (GV) arrest? SUMMARY ANSWER: Four of nine independent families with oocyte GV arrest were identified with biallelic PATL2 mutations, suggesting that these mutations may be responsible for oocyte maturation arrest in primary infertile women. WHAT IS KNOWN ALREADY: Recently, two independent studies have demonstrated that infertility in some women with oocyte maturation arrest at the GV stage was caused by biallelic mutations in PATL2. PATL2 encodes protein PAT1 homolog 2, an RNA-binding protein that may act as a translational repressor. STUDY DESIGN, SIZE, DURATION: In this study, nine unrelated primary infertile females presenting with oocyte GV arrest were recruited during the treatment of early rescue ICSI or ICSI from January 2013 to December 2016. PARTICIPANTS/MATERIALS, SETTING, METHODS: Genomic DNA was isolated from blood samples obtained from all nine affected individuals and all of their available family members. All the coding regions of PATL2 were sequenced by Sanger sequencing. The pathogenicity of the identified variants and their possible effects on the protein were evaluated in silico. MAIN RESULTS AND THE ROLE OF CHANCE: Five novel point mutations and one recurrent splicing mutation in PATL2 were identified in four of nine (44.4%) unrelated patients. We found a consanguineous family with a homozygous missense mutation in two affected sisters, and their fertile brother. There were no clear phenotypic differences in oocytes between the patient with the homozygous missense mutation, patients with nonsense mutations and undiagnosed patients. LARGE SCALE DATA: n/a. LIMITATIONS, REASONS FOR CAUTION: The function of PATL2 remains largely unknown. Both the exact pathogenic mechanism(s) of mutated PATL2 causing human oocyte maturation arrest and the strategies to overcome this condition should be further investigated in the future. WIDER IMPLICATIONS OF THE FINDINGS: According to our data, mutations in PATL2 account for 44.4% of the individuals with oocyte GV arrest. Our study further confirms that PATL2 is required for human oocyte maturation and female fertility, which indicates a potential prognostic value of testing for PATL2 mutations in primary infertile women with oocyte maturation arrest. STUDY FUNDING/COMPETING INTEREST(S): Natural Science Foundation of Anhui Province (1808085MH241), National Natural Science Foundation of China (81401251 and 81370757) and Central Guided Local Development of Science and Technology Special Fund (2016080802D114) supported this study. None of the authors have any competing interests.

Mutation analysis of the TUBB8 gene in nine infertile women with oocyte maturation arrest.

Mutations in the tubulin beta 8 class VIII (TUBB8) gene have been proven to cause oocyte maturation arrest. The aim of this study was to describe newly discovered mutations in TUBB8 and to investigate the prevalence of TUBB8 mutations in our cohort. Nine women with oocyte maturation arrest and 100 fertile female controls were recruited. Sanger sequencing of the coding regions of TUBB8 revealed a heterozygous variant c.535G > A (p.V179M) in two unrelated affected individuals and a heterozygous variant c.5G > T (p.R2M) in one affected individual. These TUBB8 variants were inherited from the unaffected fathers and were absent in 100 fertile female control individuals. In total, 33.33% (3/9) of the affected individuals in our cohort obtained a clear genetic diagnosis through sequencing of the TUBB8 gene. These two novel variants extend the spectrum of TUBB8 mutations and this study confirmed that TUBB8 mutations occur in a high proportion of infertile women with oocyte maturation arrest.

Oocytes with a dark zona pellucida demonstrate lower fertilization, implantation and clinical pregnancy rates in IVF/ICSI cycles.

The morphological assessment of oocytes is important for embryologists to identify and select MII oocytes in IVF/ICSI cycles. Dysmorphism of oocytes decreases viability and the developmental potential of oocytes as well as the clinical pregnancy rate. Several reports have suggested that oocytes with a dark zona pellucida (DZP) correlate with the outcome of IVF treatment. However, the effect of DZP on oocyte quality, fertilization, implantation, and pregnancy outcome were not investigated in detail. In this study, a retrospective analysis was performed in 268 infertile patients with fallopian tube obstruction and/or male factor infertility. In 204 of these patients, all oocytes were surrounded by a normal zona pellucida (NZP, control group), whereas 46 patients were found to have part of their retrieved oocytes enclosed by NZP and the other by DZP (Group A). In addition, all oocytes enclosed by DZP were retrieved from 18 patients (Group B). No differences were detected between the control and group A. Compared to the control group, the rates of fertilization, good quality embryos, implantation and clinical pregnancy were significantly decreased in group B. Furthermore, mitochondria in oocytes with a DZP in both of the two study groups (A and B) were severely damaged with several ultrastructural alterations, which were associated with an increased density of the zona pellucida and vacuolization. Briefly, oocytes with a DZP affected the clinical outcome in IVF/ICSI cycles and appeared to contain more ultrastructural alterations. Thus, DZP could be used as a potential selective marker for embryologists during daily laboratory work.

Human oocyte vitrification with corona radiata, in autologous follicular fluid supplemented with ethylene glycol, preserves conventional IVF potential: birth of four healthy babies.

The aim of this study was to examine the effects of vitrification with autologous follicular fluid (AFF) supplemented with ethylene glycol (EG) and sucrose on human oocytes with corona radiata. A total of 182 human oocytes with corona radiata from fifteen infertile patients were vitrified using either equilibration solutions (ES) and vitrification solution (VS) consisting of AFF, EG and sucrose (AFF group, n=67) or commercial ES and VS (control group, n=115). All oocytes were thawed in the next cycle, with surviving oocytes being inseminated by conventional IVF. The clinical outcome of vitrified-warmed oocytes by both vitrification methods was analysed retrospectively. In the AFF group, six patients received embryo transfer, with three couples taking four healthy babies home. In the control group, nine patients received embryo transfer, with four couples taking five healthy babies home. There was no significant difference in the survival rate (91.0 vs 92.2%), two pronuclei (2PN) fertilisation rate (73.8 vs 73.6%), cleavage rate (100 vs 100%), top-quality embryo rate (62.2 vs 59.2%), clinical pregnancy rate (50.0 vs 44.4%), implantation rate (33.3 vs 25%) or take-home baby rate (50.0 vs 44.4%) between the AFF group and the control group, respectively. These results show that AFF supplemented with EG and sucrose is an efficient, cost-effective cryoprotectant for human oocyte cryopreservation. A corona radiata on vitrified-warmed oocytes retains the oocytes' fertilisation capability in conventional IVF.

Extended culture of vitrified-warmed embryos in day-3 embryo transfer cycles: a randomized controlled pilot study.

Synchronization between embryonic stage and endometrium is vital to achieve a successful pregnancy. The objective of this study was to assess the implantation, clinical pregnancy and live birth rates of cryopreserved embryo transfer cycles using embryos after extended culture for 16h. A prospective randomized controlled pilot study was performed on women who underwent vitrified-warmed embryo transfer. Of the 540 women assessed for eligibility, 479 were randomly allocated to either extended culture for 16-18h (EC group, n=242) or conventional culture for 2h (control group, n=237). Endometrial preparation was the same in both groups. No significant differences were found between the extended culture and control groups respectively in clinical pregnancy rate per embryo transfer (42.48% versus 40.95%), implantation rate (21.79% versus 20.82%) or live birth rate per embryo transfer (37.61% versus 34.05%); however, the spontaneous reduction rate was lower in the extended culture group (10.04% versus 20.80%; P=0.032) In conclusion, extended culture of day-3 cleavage embryos for 16h would not influence the pregnancy outcome of day-3 cryopreserved embryo transfer cycles. Synchronization between embryonic stage and endometrium is vital to achieve a successful pregnancy and most implantation failures are possibly associated with inadequate endometrial receptivity or defects in the embryo-endometrium crosstalk. In this paper, we regulated synchronization via extended post-warming culture using conventional day-3 endometrial preparation in vitrified-warmed embryo transfer cycles and observed the clinical outcomes, including implantation, clinical pregnancy and live birth rates. Extended post-warming culture did not influence the clinical outcomes. This study implies that transfer of embryos at an advanced developmental stage may not affect implantation. This gives clinical doctors more flexibility in the performance of routine cryopreserved embryo transfer cycles.

[Ultra-rapid cryopreservation of human spermatozoa with different concentrations of sucrose].

OBJECTIVE: To explore the feasibility of ultra-rapid freezing of human spermatozoa in the cryogenic vial with different concentrations of sucrose solution. METHODS: We divided 40 normal semen samples prepared with the routine swim-up technique into 6 aliquots, 1 as the control and the other 5 cryopreserved with sucrose solution at the concentrations of 0.15, 0.20, 0.25 and 0.30 mol/L, respectively. After thawing, we determined and compared the motility, progressive motility and plasma membrane integrity of the sperm among the 6 groups. RESULTS: The motility, progressive motility and plasma membrane integrity of the sperm were significantly lower after thawing than before cryopreservation ([96.2 +/- 1.8]%, [93.8 +/- 2.8]% and [99.0 +/- 0.8 ]%) (P<0.05). Post-thawing sperm motility was (55.5 +/- 6.3)% in the 0.20 mol/L sucrose group, significantly higher than in the 0.15, 0.25 and 0.30 mol/L groups ([45.9 +/- 6.6]%, [50.4 +/- 9.4]% and [45.5 +/- 11.2]%) (P<0.05), and it was (53.6 +/- 5.0)% in the conventional freezing group, with no statistically significant difference from the 0.20 and 0.25 mol/L sucrose cryopreservation groups (P> 0.05), but remarkably higher than in the 0.15 and 0.30 mol/L groups (P<0.05). Post-thawing progressive sperm motility exhibited no statistically significant differences between the 0.20 mol/L sucrose and conventional freezing groups ([44.4 +/- 7.4]% vs [42.3 +/- 8.1]%, P>0.05), but markedly higher in both than in the 0.15, 0.25 and 0.30 mol/L sucrose groups ([37.1 +/- 8.3 ]%, [33.1 +/- 9.2]% and [22.0 +/- 9.1]%) (P<0.05). Post-thawing plasma membrane integrity was significantly higher in the 0.20 mol/L sucrose cryopreservation group ( [70.1 +/- 6.9]%) than in either the conventional freezing group ([63.1 +/- 6.8]%) or the 0.15, 0.25 and 0.30 mol/L sucrose groups ([57.7 +/- 8.3]%, [63.5 +/- 10.7]% and [57.8 +/- 12.9]%) (P<0.05). CONCLUSION: As a simple, safe and effective method, ultra-rapid freezing with sucrose solution at the final concentration of 0.20 mol/L can be used for the cryopreservation of human spermatozoa.

Fertilization rates are improved after IVF if the corona radiata is left intact in vitrified-warmed human oocytes.

BACKGROUND: Before human MII oocytes are vitrified they are usually denuded from their cumulus cells. In this study we wanted to investigate the effects of an intact corona radiata on the vitrification and fertilization of human oocytes. METHODS: The study comprised two different parts. In Part 1, 36 MII stage oocytes, from 6 patients, were randomly assigned into a control group, a group of vitrified-warmed oocytes without a corona radiata and a group of vitrified-warmed oocytes with an intact corona radiata. In each group of 12, 6 oocytes were used for evaluation of the zona pellucida solubility (hardening) and another 6 oocytes were used for the analysis of their ultrastructure. In addition, six polyspermically fertilized oocytes were used as positive controls for zona pellucida hardening. In Part 2, 16 patients in total produced 107 fresh and 98 vitrified-warmed oocytes, with or without an intact corona radiata. All oocytes were fertilized via conventional IVF and embryos were transferred according to our standard ET routines. The oocyte survival and fertilization rates, embryo quality and pregnancy and implantation rates were evaluated. RESULTS: There were no differences in oocyte survival, zona pellucida solubility (hardening) or the number of cortical granules between the vitrified-warmed and fresh oocytes. There were also no differences in the zona pellucida solubility and the number of cortical granules between vitrified-warmed oocytes with or without an intact corona radiata. However, the oocytes with an intact corona radiata had a higher fertilization rate after conventional IVF insemination. No differences were seen in the survival and cleavage rates, the percentage of high-quality embryos or the clinical outcome. CONCLUSIONS: Zona hardening and ultrastructural damage do not seem to occur in vitrified human oocytes. An intact corona radiata in vitrified-warmed oocytes retains their fertilization capacity in conventional IVF, but does not improve the embryo quality. Poor fertilizing capacities of vitrified-warmed oocytes without an intact corona radiata seem to have been due to the complete removal of the cumulus cells.

Inhibition of follicular development induced by chronic unpredictable stress is associated with growth and differentiation factor 9 and gonadotropin in mice.

Chronic psychosocial stress negatively affects ovarian function. Ovarian follicular development is regulated by both pituitary-derived gonadotropins and intraovarian regulatory factors. To date, the suppressive effects of chronic stress on the ovary have been observed to be manifested mainly as an inhibition of gonadotropin release. It is not clear whether there are any other intraovarian regulatory mechanisms involved in this process. Growth and differentiation factor 9 (GDF9) is an important, oocyte-specific paracrine regulator required for follicular development. In this study, the chronic unpredictable mild stress model was used to produce psychosocial stress in mice. The number of different developmental stages of follicles was counted on ovarian sections stained with hematoxylin and eosin. Real-time PCR and Western blotting were used to detect the mRNA and protein levels, respectively, of GDF9. The results show that chronic unpredictable stress inhibits follicular development, increases follicular atresia, and suppresses GDF9 expression. Exogenous gonadotropin treatment partly restores the repressed antral follicular development, but has no effect on the repressed secondary follicular development associated with chronic stress. Treatment with recombinant GDF9 restores secondary follicular development. Cotreatments with GDF9 and gonadotropins restore both secondary and antral follicular development in stressed mice. These findings demonstrate that inhibition of follicular development induced by chronic unpredictable stress is associated with GDF9 and gonadotropin.

Chronic unpredictable stress decreases expression of brain-derived neurotrophic factor (BDNF) in mouse ovaries: relationship to oocytes developmental potential.

BACKGROUND: Brain-derived neurotropic factor (BDNF) was originally described in the nervous system but has been shown to be expressed in ovary tissues recently, acting as a paracrine/autocrine regulator required for developments of follicles and oocytes. Although it is generally accepted that chronic stress impairs female reproduction and decreases the expression of BDNF in limbic structures of central nervous system, which contributes to mood disorder. However, it is not known whether chronic stress affects oocytes developments, nor whether it affects expression of BDNF in ovary. METHODS: Mice were randomly assigned into control group, stressed group, BDNF-treated group and BDNF-treated stressed group. The chronic unpredictable mild stress model was used to produce psychosocial stress in mice, and the model was verified by open field test and hypothalamic-pituitary-adrenal (HPA) axis activity. The methods of immunohistochemistry and western blotting were used to detect BDNF protein level and distribution. The number of retrieved oocytes, oocyte maturation, embryo cleavage and the rates of blastocyst formation after parthenogenetic activation were evaluated. RESULTS: Chronic unpredictable stress decreased the BDNF expression in antral follicles, but didn't affect the BDNF expression in primordial, primary and secondary follicles. Chronic unpredictable stress also decreased the number of retrieved oocytes and the rate of blastocyst formation, which was rescued by exogenous BDNF treatment. CONCLUSION: BDNF in mouse ovaries may be related to the decreased number of retrieved oocytes and impaired oocytes developmental potential induced by chronic unpredictable stress.