The Impact of Individual Factors on Health Information-Seeking Behavior of Infertile Couples Undergoing Assisted Reproductive Technologies: Longo Model.

Background: This study investigated the impact of individual factors on the Health information-seeking behavior (HISB) of infertile couples undergoing Assisted Reproductive Technologies (ART). Materials and Methods: This applied study was done using the descriptive-analytical method. The population of the study remains to be infertile couples undergoing ART referred to a public Infertility Center and a private one in Bandar Abbas (capital of Hormozgan province, Southern Iran) in the summer of 2020. Using simple random sampling, 168 people were selected. The data collection tool was a questionnaire extracted from Longo HISB Model, used after validation and reliability. Data were analyzed by SPSS software using descriptive and inferential tests. Results: The results showed that individual factors (gender, education, income, age, and cause of infertility) affect the HISB of infertile couples. Based on the analysis of variance, there was a significant difference between infertile couples concerning Passive Information Receipt (F = 2.688 and P = 0.048) so the couples with a male cause used Passive Information Receipt more. Conclusions: Considering the results, it is necessary for the country's health system to take appropriate measures to provide an appropriate situation for better decision-making for infertile couples and improve the chances of fertility by reducing the existing inequalities to Active Information Receipt and quality health information.

High levels of follicular fluid testosterone could impair oocyte developmental competency via affecting aryl hydrocarbon receptor pathway in PCOS patients.

BACKGROUND: Although hormonal and metabolic dysfunction have been recognized as a possible cause of polycystic ovarian syndrome (PCOS), the associations between hyperandrogenism and aryl hydrocarbon receptor (Ahr) signaling pathway remains controversial. The current study aimed to investigate the effect of hyperandrogenism on oocyte developmental competency via regarding Ahr signaling downstream pathway in granulosa cells. MATERIALS AND METHODS: Granulosa cells were collected from 45 PCOS patients under assisted reproductive technique (ART). Gene expression of Ahr downstream pathway was evaluated based on Reverse Transcription Q-PCR assay. Moreover the correlation was investigated between gene expression and hyperandrogenism, and oocyte developmental competency in PCOS. RESULTS: From the 45 PCOS patients, 26 (64.44%) had a high level of follicular fluid testosterone (FFT). Based on the FFT level, two groups of PCOS: HFT (high level of FFT) and non-HFT, were shown significant differences in oocyte and embryo quality, and fertilization and cleavage rates. Moreover, the mean relative expressions of Ahr and Arnt genes were significantly higher in HFT -PCOS group (p < 0.01 and p < 0.01) respectively. Also, the significant positive correlations were obtained for Ahr, Arnt, Cyp1A1, and Cyp1B1 with incidence of clinical hyperandrogenism and FFT level. Besides, our results showed that Ahr, Cyp1A1, and Cyp1B1 gene expression was correlated significantly with fertilization rate. CONCLUSION: The present study suggested that hyperandrogenism could impair oocyte developmental competency via affecting Ahr signaling downstream pathway.

Comparison of the efficacy of bone morphogenetic protein-4 on in vitro differentiation of murine adipose and bone marrow mesenchymal stem cells into primordial germ cells.

Background and purpose: In vitro development of functional gametes from pluripotent stem cells is a promising prospect to treat infertility. Mesenchymal stem cells with a high degree of plasticity and less tumorigenicity are a reliable source of stem cells for the generation of gametes. The present study aimed to compare the differentiation potential in the mesenchymal stem cells that are derived from bone marrow (BMDMSCs) and adipose tissue derived mesenchymal stem cells (AD-MSCs) into germ cells in a culture medium containing bone morphogenic protein-4 (BMP-4). Experimental approach: In this study, MSCs were isolated from both bone marrow and adipose tissue of murine samples. To further verify the nature of the harvested stem cells, their multipotency and surface marker were examined. The identified stem cells were cultured in a medium supplemented with 0 and 25 ng/mL of BMP-4 for 4 days. Flow cytometry analysis, immunofluorescence staining, and real RT-PCR were used to assess the expression levels in germ cell-specific biomarkers (Mvh, Dazl, Stra8, and Scp3). Findings/Results: CD44+, CD45-, CD31-, BMD-MSCs, and AD-MSCs showed to be capable of differentiating to osteo-adipogenic lineages. The flow cytometry, immunofluorescence, and RT-PCR results indicated that early germ cell markers (Mvh and Dazl) were expressed in both types of cells but they were significantly higher in BMD-MSCs than AD-MSCs. Conclusion and implications: Based on our results, the addition of exogenous BMP4 to the culture medium could differentiate BMD-MSCs and AD-MSCs into primordial germ cells, but it is inadequate to further develop into late germ cells in vitro. Moreover, the results revealed that, although AD-MSCs were easier to collect and had faster growth and proliferation rates than BMD-MSCs, the BMD-MSCs were better capable of differentiation into primordial germ cells. They may serve to be considered a more suitable source of MSC for in vitro generation of gametes than AD-MSCs.

Construction of circRNA-miRNA-mRNA network in the pathogenesis of recurrent implantation failure using integrated bioinformatics study.

This research attempted to elucidate the molecular components are involved in the pathogenesis of recurrent implantation failure (RIF). We initially identified that 386 mRNAs, 144 miRNAs and 2548 circRNAs were differentially expressed (DE) in RIF and then investigated the genetic cause of the observed abnormal expression by constructing a circRNA-miRNA-mRNA network considering the competing endogenous RNA theory. We further analysed the upstream transcription factors and related kinases of DEmRNAs (DEMs) and demonstrated that SUZ12, AR, TP63, NANOG, and TCF3 were the top five TFs binding to these DEMs. Besides, protein-protein interaction analysis disclosed that ACTB, CXCL10, PTGS2, CXCL12, GNG4, AGT, CXCL11, SST, PENK, and FOXM1 were the top 10 hub genes in the acquired network. Finally, we performed the functional enrichment analysis and found that arrhythmogenic right ventricular cardiomyopathy (ARVC), hypertrophic cardiomyopathy (HCM), pathways in cancer, TNF signalling pathway and steroid hormone biosynthesis were the potentially disrupted pathways in RIF patients. Optimistically, our findings may deepen our apprehensions about the underlying molecular and biological causes of RIF and provide vital clues for future laboratory and clinical experiments that will ultimately bring a better outcome for patients with RIF.

Health Information Needs of Couples Undergoing Assisted Reproductive Techniques.

Background: Couples undergoing Assisted Reproductive Techniques (ART) come across various information needs. This study aimed to identify the health information needs of couples undergoing ART. Materials and Methods: The methodology of the present applied study was qualitative and the research method was conventional qualitative content analysis performed with the participation of 25 infertile couples under ART. The study took nine months (July 2020 to March 2021). The samples were objectively screened based on the criteria from the couples referred to the infertility center affiliated to Hormozgan University of Medical Sciences (Public) and Ome-Leila Specialized infertility clinic (Private) in Bandar Abbas (Iran). Data collection was performed by semi-structured interviews. The typical content analysis method was used in this research. Data analysis was carried out based on coding by the use of MAXQDA a software for qualitative and mixed methods data analysis. Results: Information needs of couples under ART were categorized into three main categories and ten subcategories: 1) main cause of infertility [feminine or masculine cause, and etiology (nature and origin)], 2) treatment of infertility [identifying ART, treatment success rate, complications and risks (outcomes) of the treatment method, and treatment duration], and 3) healthcare [advice on medication, healthy nutrition (diet), sexual relations, and daily routine]. Conclusions: The results of this study emphasize that the country's health officials, especially those in charge of the healthcare of infertile couples under ART, must necessarily pay more attention to meeting the needs of this group of people in society.

Normal seminal plasma could preserve human spermatozoa against cryopreservation damages in Oligozoospermic patients.

BACKGROUND: Cryopreservation of human spermatozoa has been identified as an efficient procedure to preserve fertility in men before any cancer therapy or surgical infertility treatment. Despite the benefits of the procedure, the deleterious effects of cryopreservation have been proven on sperm structure and function. This study aimed to evaluate seminal plasma effects on human sperm characteristics after cryopreservation, and compare the addition of normozoospermic and oligozoospermic seminal plasma in the prepared oligozoospermic samples. Semen samples were collected from fifty-five oligozoospermic men and the twenty fertile individuals who referred to the infertility center. At first, a semen analysis was carried out on each neat ejaculate, and then some were cryopreserved. The remainder of the semen was divided into two, one for seminal plasma removal and the other for sperm preparation. Then, the prepared spermatozoa were cryopreserved in three groups: one with, and another without the addition of oligozoospermic seminal plasma, and still another with the addition of normal seminal plasma. After thawing, sperm DNA integrity, viability, motility, and morphology were determined. RESULTS: The percentages of all parameters were significantly lower after cryopreservation in all groups compared to the fresh sample. However, this reduction was lower in the oligozoospermic samples cryopreserved with normal seminal plasma. CONCLUSION: The results indicated that seminal plasma in oligozoospermic patients could not support sperm against cryo-injuries, an indication likely due to insufficient antioxidants and other protective components in oligozoospermic patients. However, normal seminal plasma could slightly preserve sperm characteristics after cryopreservation in oligozoospermic patients.

Effect of bacterial infection on sperm quality and DNA fragmentation in subfertile men with Leukocytospermia.

BACKGROUND: Although bacterial infections have been recognized as a possible cause of male infertility, the effect of bacterial infections on sperm quality and sperm DNA fragmentation remains controversial. The current study aimed to investigate the prevalence rate of bacterial infection in subfertile men and its effect on semen quality. Seminal fluid was collected from 172 male members of infertile couples attending the andrology infertility center and a group of 35 fertile subjects as a control. Sperm parameters and DNA fragmentation were evaluated based on the type of bacteria in all ejaculates. RESULTS: From the 172 patients investigated for infertility, 60 (34.88%) patients had a positive culture for pathogenic bacteria of different species. Leukocytospermia was significantly higher in infected samples in comparison with non-infected samples (p < 0.05). Sperm concentration and motility and morphology were significantly lower in infected than non-infected samples. Moreover, sperm DNA fragmentation was significantly higher in infected than non-infected samples. Besides, our results showed that sperm DNA fragmentation was correlated significantly with leukocytospermia (R: 0.22, p < 0.01). CONCLUSION: The present study suggested that bacterial infection significantly correlated with leukocytospermia could impair male fertility potential through decreasing sperm motility, morphology, and DNA integrity.

Assessment of Mitochondrial Function and Developmental Potential of Mouse Oocytes after Mitoquinone Supplementation during Vitrification.

Vitrification negatively affects the mitochondrial membrane potential (ΔΨm) in oocytes while also leading to increased reactive oxygen species (ROS), ATP depletion and induction of apoptosis in oocytes. Mitoquinone (MitoQ) is an antioxidant that protects mitochondrial membrane integrity from ROS. This study examined the effect of adding MitoQ to vitrification medium on mitochondrial function and embryo development in vitrified oocytes. Metaphase II (MII) stage oocytes were collected from NMRI mouse ovaries and preincubated for 20 min in a medium containing 0.02 µM of MitoQ. Next, oocytes were vitrified in medium supplemented with 0.02µM of MitoQ (treatment group). The control group was processed in the same way but without exposure to MitoQ. After warming, oocyte survival rate, ΔΨm, cytoplasmic ROS and glutathione (GSH) levels and gene expression levels (Bcl2, BAX, and caspase3) were measured. In addition, the vitrified oocytes were fertilized in-vitro to assess developmental competence. The results showed that MitoQ improved survival and ΔΨm in treated vitrified oocytes. Treated oocytes showed lower ROS levels and higher GSH levels than did the control group. Furthermore, mRNA expression of the Bax/ Bcl2 ratio and caspase3 were significantly lower in treated oocytes. These findings indicate that medium supplementation with 0.02 µM of MitoQ during vitrification can improve oocyte survival and developmental competency in mouse oocytes.

The effect of Myo-inositol on fertility rates in poor ovarian responder in women undergoing assisted reproductive technique: a randomized clinical trial.

BACKGROUND: Poor ovarian response to gonadotropin is a significant challenge in assisted reproductive technique (ART) and affect 9-24% of ART cycles. This study aimed to evaluate the effect of Myo-inositol on fertility rates in poor ovarian responder women undergoing assisted reproductive technique. METHODS: This study is a double-blinded randomized controlled study that involved 60 poor ovarian responders included in an ICSI program and divided into two groups; intervention group: 30 patients who have been assuming Inofolic (4 g myo-inositol + 400 µg folic acid) for the before the enrollment day; control group: 30 patients assuming folic acid (400 µg) for the same period. Controlled ovarian stimulation was performed in the same manner in the two groups. The main outcomeswere the assessment of oocytes retrievednumber and quality, ovarian sensitivity index,required dose of Gonadotropinsunits × 1000), fertilization rate, biochemical, and clinical pregnancy rate. RESULT: There is no significant difference in clinical characteristics between study groups. The number of oocytes retrieved, number of MII oocytes, number of embryos transferred, chemical, and clinical pregnancy were higher in the intervention group. However, they are not statistically significant in comparison to the control group. The ovarian sensitivity index and fertilization rate were significantly higher in the intervention group than the control group (P > 0.05). The required dose of gonadotropin significantly lower in the intervention group than the control group. CONCLUSION: Our results suggest that the supplementation myo-inositol in poor ovarian responders significantly improved the ART outcomes such as fertilization rate gonadotropin, ovarian sensitivity index (OSI) and significantly reduced the required unities of gonadotropin. Additionally, more extensive randomized controlled studies are needed. TRIAL REGISTRATION: Iranian Registry of Clinical Trials, IRCT20180515039668N1 , retrospectively registered since 2020-03-16.

Comparison of TGF-ß3 and avocado/soybean unsaponifiable on chondrogenesis of human adipose-derived stem cells on poly (lactic-co-glycolic) acid/ hyaluronic acid hybrid scaffold.

OBJECTIVES: Avocado/soybean unsaponifible (ASU) possesses properties including chondroprotective, anticatabolic, and anabolic. The goal behind this research was to detect the effect of ASU and TGF-ß3 on the chondrogenesis of human adipose-derived stem cells (hADSCs) on poly (lactic-co-glycolic) acid (PLGA)/ hyaluronic acid (PLGA/HA) hybrid scaffold. MATERIALS AND METHODS: First hADSCs were seeded in PLGA/Hyaluronic acid scaffold and cultured in chondrogenic media. These cells were assigned into 4 groups: control, TGFß-3, ASU, and TGFß-3+ASU. The viability was assessed separately by MTT. Real-time PCR was used to quantify the expression of chondrogenic specific genes [Sox9, collagen type II (ColII), Aggrecan (AGG)] and collagen type X (ColX). Moreover, Western blotting was employed to evaluate protein expression levels of collagens type II and X. RESULTS: These findings indicated a significant increase in the proliferation and survival of hADSCs differentiated cells by ASU compared with the control group (P=0.008). Real-time PCR results revealed significant differences in the expression of AGG, SOX9, ColII, and ColX genes in the control group when compared with other groups (ASU, TGF-ß3, and TGF-ß3+ASU). ColII protein production significantly dropped in the TGF-ß3 group in comparison with the TGF-ß3+ASU group (0.000). The ColII (P=0.002) and ColX (P=0.002) protein production proved significantly higher in the TGF-ß3+ASU group compared with the ASU group. CONCLUSION: Using the synergist form TGFß-3, ASU induces chondrogenesis in hADSCs in PLGA/HA composite scaffold. This can be deduced with reduction of special markers of hyaline cartilage in comparison with ASU and decreased hypertrophic marker compared with TGF-ß3.

Improvement in the epigenetic modification and development competence in PCOS mice oocytes by hydro-alcoholic extract of Nigella sativa during in-vitro maturation: An experimental study.

BACKGROUND: Nigella Sativa (NS) and its active component, thymoquinone, have beneficial protective effects on experimental animal models of polycystic ovary syndrome (PCOS) and different human diseases. OBJECTIVE: The present study aimed to investigate the effects of NS hydro-alcoholic extract (NSE) on the oocyte quality of PCOS mice during in vitro maturation. MATERIALS AND METHODS: For induction of PCOS, 40 prepubertal 21-days old female B6D2F1 mice (18-22 g body weight) received subcutaneous dehydroepiandrosterone daily. After validation of the model, germinal vesicle-stage oocytes of superovulated mice were collected and placed in the culture medium containing different concentrations (0, 1, 50, and 100 µg/ml) of NSE. For the measurement of developmental competency, some mature oocytes were fertilized with epididymal spermatozoa. Other mature oocytes were assessed for oxidative stress. Also, some mRNA expression levels involved in oocyte maturation and epigenetic modification were evaluated. RESULTS: The 50 µg/ml NSE treated group showed significantly higher r ates o f maturation, f ertilization, and blastocyst formation in comparison with both control and PCOS groups. A high level of glutathione concentration and glutathione peroxidase mRNA expression, besides a low level of reactive oxygen species content all, were observed in oocytes treated with 50 µg/ml NSE, indicating the modification of oxidative statue. Furthermore, the oocytes in the 50 µg/ml-treated group showed an upregulation of mRNA expression in epigenetic-related genes (Dnmt1 and Hdac1) and maternally derived genes (Mapk and Cdk1), correspondingly downregulation of cyclooxygenase2 mRNA expression, in comparison to other groups. CONCLUSION: The results of this study indicated that 50 µg/ml NSE improves oocyte maturation, oxidative statues and epigenetic modifications. These may be the all reasons for the developmental competency in the control and PCOS mice oocytes.

Exposing Mouse Oocytes to MitoQ During In Vitro Maturation Improves Maturation and Developmental Competence.

BACKGROUND AND PURPOSE: Mitochondrion is the main indicator of oocyte quality and one of the components of oocyte, which is sensitive to oxidative damage during the maturation process. Mitoquinone mesylate (MitoQ) is a strong antioxidant targeting mitochondria as well as anti-apoptotic agent. However, the effect of MitoQ on the quality of oocytes during in vitro maturation (IVM) is still unknown. OBJECTIVES: This study investigated the possible effects of MitoQ on maturation and developmental competency in mice oocytes. MATERIALS AND METHODS: The oocytes were collected at germinal vesicle stage from 6-8-week old female NMRI mice and then cultured in TCM-199 medium supplemented with 0, 0.01, 0.02 and 0.04 µM MitoQ. The sham group was treated with DMSO (0.01% v.v). Then intracellular Glutathione (GSH), reactive oxygen species (ROS) levels, mitochondria membrane potential (ΔΨm), as well as in vitro fertilization (IVF) rate in the 18-20 h matured oocytes and metaphase II (MII) oocytes (in vivo-control), were assessed. RESULTS: The results showed that between three dose of MitoQ, the 0.02 µM significantly increased nuclear maturation rate, GSH level, fertilization rate and blastulation (92.6, 231.7, 90.19 and 81.66%, respectively) than the in vitro-control (71.14, 152, 78.84 and 73.50%, respectively) and more comparable to that of the in vivo matured oocytes (100, 243.5, 92.10 and 83%, respectively). Also, the mitochondria membrane potential in the 0.02 µM MitoQ was significantly higher compared with those in the other groups (4.4). However, the intracellular ROS level in 0.02 µM MitoQ was significantly decreased (38.72%) compared to in vitro-control (82.2%) and was similar to the in vivo-control (33.5%). CONCLUSION: The results indicated that supplementation of IVM medium with MitoQ (specially 0.02 µM) enhance maturation and fertilization rate. In conclusion, MitoQ might be considered as a novel component that could be added to IVM media.

The antioxidant curcumin postpones ovarian aging in young and middle-aged mice.

Reproductive senescence is accompanied by a reduced number and quality of ovarian follicles in response to the accumulation of free radicals and the process of apoptosis. Having selected mice as models, we examined the hypothesis that curcumin as an antioxidant and anti-inflammatory agent might prevent or retard ovarian aging. Female NMRI 21-day-old mice were divided into control, vehicle and curcumin groups. In the treatment group the mice received curcumin at 100mgkg-1day-1 intraperitoneally. After 6, 12 and 33 weeks several parameters were examined including ovarian reserve, oocyte quality, oxidative status, invitro fertilisation and expression of ovulation-related (growth differentiation factor 9 (GDF-9) and bone morphogenetic protein 15 (BMP-15)) and anti-aging-related (sirtuin 1 (SIRT-1) and SIRT-3) genes. Curcumin treatment up to 12 and 33 weeks resulted in increased ovarian volume and number of follicles and was associated with elevated anti-Müllerian hormone and oestrogen and diminished FSH serum levels. Furthermore, enhanced oocyte maturation, fertilisation and embryo development plus reduced oxidative stress were seen in the curcumin group. Also, the expression of GDF-9, BMP-15, SIRT-1 and SIRT-3 genes was increased in the curcumin group. Concerning gestational age, the findings of the study suggested that administration of curcumin could delay the process of oocyte aging in a mouse model.

Thymoquinone reduces intracytoplasmic oxidative stress and improves epigenetic modification in polycystic ovary syndrome mice oocytes, during in-vitro maturation.

Although in-vitro maturation (IVM) of oocytes has been presented as an alternative treatment to traditional stimulated in-vitro fertilization, the culture condition can be improved by natural antioxidants. Thus, we investigated the protective effect of Thymoquinone (TQ) during IVM in the polycystic ovary syndrome (PCOS) mice model. The induction of PCOS was made by dehydroepiandrosterone via subcutaneous injection, in prepubertal female B6D2F1-mice. After 21 days later, germinal vesicle (GV)-stage-oocytes were extracted and incubated in IVM media containing 0, 1.0, 10.0, and 100.0 µM of TQ. To assess fertilization and blastulation rates, after 22-24 hr, the treated oocytes were fertilized in-vitro with epididymal spermatozoa. Some other oocytes were evaluated for maturation, epigenetic, and oxidative stress markers. Similarly, the mRNA expression of epigenetic enzymes genes (Dnmt1 and Hdac1), three maternally derived genes (Mapk, CyclinB, and Cdk1) and apoptosis-related genes (Bax and Bcl2) were assessed. Our results showed that the maturation, fertilization, and blastulation rates were significantly higher in the 10.0 µM TQ-treated group compared with the untreated group and likewise with in-vivo matured oocytes. The Bax expression was reduced in 10.0 µM TQ matured oocytes, but Bcl2, Dnmt1, Hdac1, Cdk1, and Mapk were upregulated in this group compared to other groups. Furthermore, dimethylation of histone-3 at lysine-9 (H3K9m2) and DNA methylation were significantly increased whereas H4K12 acetylation (H4K12ac) was decreased in the 10.0 µM TQ-treated group in comparison with control and in-vivo matured oocytes. Therefore, our results are suggesting that 10.0 µM TQ may enhance the developmental competence of PCOS oocytes via the modulation of oxidative stress and epigenetic alterations.

Improvement of oocyte in vitro maturation from mice with polycystic ovary syndrome by human mesenchymal stromal cell-conditioned media.

The outcome of in vitro maturation (IVM) in the patients with polycystic ovary syndrome (PCOS) is poor. Abnormal intraovarian paracrine interplay alters microenvironment for oocyte development through folliculogenesis and decreases developmental competence of oocytes in patients with PCOS. Mesenchymal stromal cells (MSCs) secrete a variety of cytokines and growth factors that could promote oocyte maturation in vitro. Thus, in the current study we aimed to evaluate the effect of human bone marrow MSC-conditioned media (hBM-MSC-CM), as a supplement, to enrich IVM medium for PCOS germinal vesicles (GVs). For this purpose, oocytes at GV and metaphase II (MII) stages were harvested from PCOS mice. The GVs were randomly divided into four groups and incubated for 24 hours in an IVM medium (TCM199, as the control group) or TCM199 supplemented by 25%, 50%, and 75% of hBM-MSC-CM (PCOS-CM25, PCOS-CM50, and PCOS-CM75 groups, respectively) so as to evaluate which dose(s) could enhance maturation rate of the GVs and their subsequent in vitro fertilization (IVF) outcome. Furthermore, MII oocytes and their subsequent IVF outcome were considered as the in vivo matured (PCOS-IVO) group. The data showed that supplementation of IVM medium with 50% hBM-MSC-CM significantly increased cytoplasmic and nuclear maturation of the GVs (P < 0.001), and also fertilization and two-cell rate (P < 0.001) and blastocyst formation (P < 0.01) of in vitro matured oocytes from mice with PCOS. Overall, higher oocyte maturation and fertilization outcome in PCOS-CM50 group proposed that enrichment of IVM medium with hBM-MSC-CM could be considered as a promising approach to improve IVM of PCOS oocytes.

Intracytoplasmic oxidative stress reverses epigenetic modifications in polycystic ovary syndrome.

In polycystic ovary syndrome (PCOS), substantial genetic and environmental alterations, along with hyperandrogenism, affect the quality of oocytes and decrease ovulation rates. To determine the mechanisms underlying these alterations caused specifically by an increase in plasma androgens, the present study was performed in experimentally-induced PCOS mice. As the study model, female B6D2F1 mice were treated with dehydroepiandrosterone (DHEA, 6mg per 100g bodyweight). After 20 days, oocytes at the germinal vesicle and metaphase II stages were retrieved from isolated ovaries and subsequent analyses of oocyte quality were performed for each mouse. DHEA treatment resulted in excessive abnormal morphology and decreased polar body extrusion rates in oocytes, and was associated with an increase in oxidative stress. Analysis of fluorescence intensity revealed a significant reduction of DNA methylation and dimethylation of histone H3 at lysine 9 (H3K9) in DHEA-treated oocytes, which was associated with increased acetylation of H4K12. Similarly, mRNA expression of DNA methyltransferase-1 and histone deacetylase-1 was significantly decreased in DHEA-treated mice. There was a significant correlation between excessive reactive oxygen species (ROS) production and increased histone acetylation, which is a novel finding and may provide new insights into the mechanism causing PCOS. The results of the present study indicate that epigenetic modifications of oocytes possibly affect the quality of maturation and ovulation rates in PCOS, and that the likely mechanism may be augmentation of intracytoplasmic ROS.