Evaluation of an Updated Gene Panel as a Diagnostic Tool for Both Male and Female Infertility.

In recent years, an increasing number of genes associated with male and female infertility have been identified. The genetics of infertility is no longer limited to the analysis of karyotypes or specific genes, and it is now possible to analyse several dozen infertility genes simultaneously. Here, we present the diagnostic activity over the past two years including 140 patients (63 women and 77 men). Targeted sequencing revealed causative variants in 17 patients, representing an overall diagnostic rate of 12.1%, with prevalence rates in females and males of 11% and 13%, respectively. The gene-disease relationship (GDR) was re-evaluated for genes due to the addition of new patients and/or variants in the actual study. Five genes changed categories: two female genes (MEIOB and TBPL2) moved from limited to moderate; two male genes (SOHLH1 and GALNTL5) moved from no evidence to strong and from limited to moderate; and SEPTIN12, which was unable to classify male infertility, was reclassified as limited. Many infertility genes have yet to be identified. With the increasing integration of genetics in reproductive medicine, the scope of intervention extends to include other family members, in addition to individual patients or couples. Genetic counselling consultations and appropriate staffing will need to be established in fertility centres. Trial registration number: Not applicable.

Ageing, a modulator of human endometrial stromal cell proliferation and decidualization: a role for implantation?

RESEARCH QUESTION: Does ageing affect endometrial stromal cell function and gene expression involved in decidualization? DESIGN: Stromal cells were isolated and cultured (98% purity) from pipelle endometrial biopsies obtained from female donors, at the proliferative phase of the menstrual cycle. Initially, 28 samples were collected (age range 25-46 years). These samples were divided into two groups: 25-35 years and 36-46 years. Cell proliferation assays were carried out to determine changes in stromal cell proliferation, in vitro, between the two groups. In addition, mRNA and protein expression of decidualization factors, BMP2 and STAT3, were analysed for the same age groups and samples using real-time polymerase chain reaction and western blot analysis, respectively. Finally, another 12 pipelle endometrial biopsies (age range 25-46 years) were used in separate in-vitro decidualization experiments. The mRNA expression of decidualization markers, prolactin and IGFBP-1 were analysed in cultured stromal cells after adding 8-bromo-cAMP. RESULTS: A statistically significant decrease was observed in stromal cell proliferation with increasing age (P = 0.0006). Messenger RNA expression of BMP2 and STAT3 were found to decrease (P = 0.0167; P = 0.0037, respectively) in the older age group. In addition, BMP2 and STAT3 protein expression between the samples analysed changed significantly (P = 0.0085; P = 0.0463, respectively) with increasing age. In-vitro induced decidualization experiments showed significant changes in stromal cell mRNA expression of decidualization markers (IGFBP1 and prolactin) between different age groups. CONCLUSION: Ageing affected endometrial cell function and gene expression. Changes in cell function and expression of associated molecules that differ in the ageing endometrium can help understand the causes of infertility.

Luteal phase support in fresh and frozen embryo transfer cycles.

Nearly 5 million babies have been delivered following assisted conception (IVF/ICSI) and the demand is increasing. Meticulous ovarian stimulation and well programmed luteal phase support are the landmarks of treatment success. Although the importance of luteal phase support in IVF/ICSI cycles is well established, the optimal route, dose and duration of this support is still a matter of debate. Regardless of the ovarian stimulation, parenteral and vaginal progesterone has been one of the most common routes. However, oral or subcutaneous routes are also well-investigated and reveal satisfactory clinical outcomes. It is obviously critical to choose a progesterone with adequate clinical efficacy and patient tolerability as well. Moreover, fresh and frozen embryo transfer cycles markedly different from each other in terms of physiological changes and luteal support concept should be modified accordingly. The aim of this narrative review is to provide evidence-based take home messages for the luteal phase support in either fresh or frozen embryo transfer cycles in the context of a recent scientific evidence.

Intrauterine G-CSF Administration in Recurrent Implantation Failure (RIF): An Rct.

This study investigates the effects of intrauterine G-CSF on endometrial thickness, clinical pregnancy rate and live birth rate in a recurrent implantation failure (RIF) group with normal endometrium. This study was designed as a prospective randomized controlled trial with the involvement of 157 RIF group pati; ents. The RIF group was formed on the basis of the RIF criteria: "The failure to achieve a clinical pregnancy after the transfer of at least four good-quality embryos in a minimum of three fresh or frozen cycles to a woman under the age of 40 years. The study sample included 82 patients in the G-CSF group who received G-CSF once a day on hCG. The procedure was performed by administering 30 mIU of Leucostim®(Filgrastim [G-CSF] 30 mIU/mL; DEM Medical, Dong-A; South Korea) through slow infusion into the endometrial cavity using a soft embryo transfer catheter. Normal saline of 1 mL was infused into the endometrial cavity in the same way in 75 patients in the control group. The standard ICSI procedure was used for all patients, and fresh cycle embryos were transferred on the third or fifth day. No statistically significant difference was identified in clinical pregnancy rates, miscarriage rates and live birth rates between the G-CSF group and the control group (p = 0.112, p = 0.171, p = 0.644, respectively), and no difference was observed between the two groups regarding endometrial thickness (p = 0.965). The intervention of administration G-CSF into the uterine cavity in RIF patients with normal endometrium, did not alter the endometrial thickness, clinical pregnancy rates, or live birth rates.

Systematic and standardized hysteroscopic endometrial injury for treatment of recurrent implantation failure.

RESEARCH QUESTION: To investigate the effect of hysteroscopic endometrial injury for treatment of recurrent implantation failure (RIF). DESIGN: This prospective and randomized controlled trial included 239 patients who had failed to achieve a clinical pregnancy after the transfer of at least four good-quality embryos in a minimum of three fresh or frozen-thawed embryo transfer cycles and were under the age of 40 years, who were randomized into two groups. The injury group (n = 124) received endometrial injury during their hysteroscopic procedure, whereas the control group (n = 115) did not. Patients who had endometrial pathologies were excluded from the study. RESULTS: There were no statistically significant differences in duration of gonadotrophin use (8.23 versus 8.30 days), total dose of gonadotrophins (2330 versus 2338 IU), number of oocytes (7.03 versus 8.21), number of mature oocytes (5.27 versus 6.02), number of fertilized oocytes (4.19 versus 4.55), number of good-quality embryos (2.07 versus 2.43), number of embryos transferred (1.97 versus 1.93) or endometrial thickness (9.04 versus 9.35 mm) between the injury group and control group, respectively. Clinical pregnancy rates (25.8% versus 15.6%, P = 0.047), live birth rates (21.8% versus 12.2%, P = 0.049) and implantation rates (14.2% versus 8.8%, P = 0.036) were significantly different, favouring the injury group. CONCLUSION: This study suggests that endometrial injury is beneficial in RIF patients to increase the odds of implantation, clinical pregnancy and live birth.

Intrauterine CRH-treated PBMC in repeated implantation failure.

BACKGROUND: The intrauterine administration of activated autologous peripheral blood monocytes (PBMC) prior to embryo transfer seems to improve reproductive outcomes in women with repeated implantation failure (RIF). We have previously shown that the intrauterine administration of PBMC treated with corticotropin-releasing hormone (CRH) prior to blastocyst transfer (day 5) improves significantly the clinical pregnancy rate of women with RIF. In the present crossover pilot study, we have investigated whether CRH-PBMC treatment could be of benefit in case of fresh early cleavage stage embryo transfer (day 3) in women with RIF. METHODS: Twenty-six (n = 26) women with at least three previous failed IVF attempts and no history of clinical pregnancy in the past were recruited in this study. Ovarian stimulation was performed following either the long or the short protocol. PBMC were collected during the oocyte retrieval, were treated with CRH, and transferred in the uterine cavity 2 days later. Good quality cleavage stage embryos were transferred at day 3, following oocyte retrieval. RESULTS: Following the intrauterine administration of CRH-treated autologous PBMC, 15/26 clinical pregnancies occurred (57.69%). Compared to the null result of the same women prior to recruitment, this observation was considered significant (P < 10-2 ). CONCLUSION: Our findings further support the role of the intrauterine administration of CRH-treated PBMC as an effective approach when transferring cleavage stage embryos in women with RIF. Prospective randomized studies are needed to clarify whether such intervention could be of benefit in clinical practice.

Natural cycle versus hormone replacement therapy cycle in frozen-thawed embryo transfer.

OBJECTIVES: To compare implantation rates, clinical pregnancy rates and live birth rates associated with natural and hormone replacement therapy (HRT) methods of endometrial preparation in frozen-thawed embryo transfer (FET) cycles.  Methods: The results of 108 natural cycles and 224 HRT cycles of FET transfers performed in a private in vitro fertilization (IVF) center between June 2013 and August 2015 were  retrospectively compared with respect to implantation rate, clinical pregnancy rate, and live birth rate. Results: A total of 144 embryos were transferred in 108 natural cycles and 357 embryos were  transferred in 224 HRT cycles. No statistically significant differences were found in the implantation rate (p=0.796), clinical pregnancy rate per cycle (p=0.900), clinical pregnancy rate per transferred embryo (p=0.283), live birth rate per cycle (p=0.821), or live birth rate per transferred embryo (p=0.481) between the 2 groups.  Conclusion: This study showed no difference between the implantation rate, clinical pregnancy rate or live birth rate between the natural cycle group and HRT cycle group. These results may provide clinicians with more freedom to individualize patient treatment, particularly with respect to the selection of the endometrial preparation method, if these results are supported by large randomized controlled studies in the future.

Maternal nutrition and reproductive functions of female and male offspring

This study aimed to investigate the effects of maternal unhealthy nutrition on the reproductive functions of female and male adult offspring. This was an animal study carried out with 24 virgin female Wistar rats (dams) and their male and female offspring. Rats were divided standard diet (SD) or cafeteria diet (CD) groups, after 10 weeks of feeding, all rats were paired with a Wistar stud male, and each group was again divided into CD and SD groups during the pregnancy and lactation periods. After birth, six female and six male pups in each group, were subjected to study. Following 3 weeks of lactation, the pups were fed with SD for 8 weeks and killed when they were considered adult at 11th week for analysis. Primordial and antral follicle counts, serum anti-Mullerian hormone (AMH) and phosphatase and tensin homolog (PTEN) in the oocyte cytoplasm were examined to evaluate ovarian function, and E-cadherin and integrin-ß1 levels were examined in endometrial tissues for the evaluation of endometrial receptivity in female offspring. Sperm analysis was performed in male offspring. In groups in which the dams were fed CD, primordial follicular pool, PTEN, and endometrial receptivity were reduced. In contrast, AMH and the number of antral follicles were not changed. In male offspring, the testicles were smaller, testosterone production decreased, AMH increased and the number and function of sperm were not changed. Sperm analysis results were not changed. All negative effects on reproductive functions were more apparent in groups fed with the CD during the pregestational period.

Fresh versus frozen-thawed blastocyst transfer in high responders.

OBJECTIVE: This study aimed to investigate and compare the pregnancy and live birth rates in IVF cycles of frozen-thawed embryo transfers and fresh embryo transfers in a group of women with a high risk of Ovarian hyperstimulation syndrome (OHSS). MATERIAL AND METHODS: The study group consisted of 254 women with a high level of response to controlled ovarian hyperstimulation. The patients who received fresh cycle embryo transfers with calcium infusions are referred to as the Fresh Ca+ group, and those without the calcium therapy are called the Fresh Ca- group; and we used correspondingly similar terminology for the Frozen group. RESULTS: We observed no statistically significant differences between the cycles of fresh and frozen-thawed embryo transfers in patients with a high risk of OHSS in terms of implantation, clinical pregnancy, and live birth rates. Furthermore, these implantation, clinical pregnancy and live birth rates were not different in the cycles with or without calcium treatment. There was no statistical difference in the OHSS rates between the fresh and frozen-thawed cycles; although, the OHSS rates were less in the two calcium infusion groups (Fresh Ca+ and Frozen-thawed Ca+) than in the without-calcium group. There was no OHSS development in the subjects of the Frozen-thawed Ca+ group. CONCLUSION: Our study results suggest that fresh and frozen-thawed embryo transfers have similar IVF results in patients with a high risk of OHSS. Calcium infusion is beneficial in preventing OHSS without altering pregnancy rates. Both IVF protocols with calcium infusion can safely be applied in high-responder patients without lowering success rates.

The effect of progesterone use in the first trimester on fetal nuchal translucency.

OBJECTIVE: To evaluate the possible association between progesterone use in the first trimester of pregnancy and fetal nuchal translucency (NT). MATERIAL AND METHODS: This is an observational case-control study, which was conducted with patients who underwent nuchal scans between March 2015 and February 2016 and consequently delivered live and healthy babies. The study group was composed of assisted reproductive technology pregnancies and used intravaginal progesterone 180 mg/day until gestational week 12. The control group comprised pregnant women who became pregnant spontaneously without using any progesterone preparation in the first trimester. RESULTS: One hundred sixty-four (57.5%) of 285 patients were in the control group and 121 (42.5%) were in the progesterone group. Age, bodyweight, gravidity, and parity number of previous births and abortus, gestational week, crown-rump lengths, free ß-human chorionic gonadotropin, pregnancy-associated plasma protein A, and NT values of the progesterone and control groups were recorded and we investigated whether there was a statistically significant difference between the two groups in terms of these parameters; maternal weight was found to be higher in the progesterone group than in the control group and the difference between the groups was statistically significant (p=0.019 and p=0.025). Whether the difference in NT was caused by the effect of maternal weight was investigated using the covariance analysis test and maternal weight was not found to be statistically significant in the model (p=0.284). CONCLUSION: Fetal NT was increased in the progesterone group compared with the untreated group in healthy pregnancies.

Autoimmune estrogen dermatitis in an infertile female.

Autoimmune estrogen dermatitis is a cyclical cutaneous eruption that occurs premenstrually and goes to the rapid resolution within a few days of menstrual cycles. The disorder has variable clinical manifestations consisting of macules, papules, vesicles, urticarial lesions, bullae, eczematous plaques, and erythema multiforme-like lesions. Herein, we present a case of a 30-year-old woman with attacks of edema and erosions involving the oral and genital mucosal sites on every first day of her menstruation period. She had also multiple endocrinological problems such as hypotroidism and infertility. To determine the sex hormon sensitivity, intradermal skin tests were performed. Based on her personal history and skin test findings, a diagnosis of autoimmune estrogen dermatitis was made. After the oophorectomy, she was free from the skin and mucosal symptoms. We propose that it is important to suspect the diagnosis of autoimmune estrogen dermatitis in patients who present with recurrent cylic eruptions and it must be kept in mind that these patients might have a concomitant infertility.

Methods for endometrial preparation in frozen-thawed embryo transfer cycles.

Frozen-thawed (FT) embryo transfer is a procedure used for the storage and transfer of excess embryos obtained during in vitro fertilization- intracytoplasmic sperm injection cycles. In recent years, improvements in laboratory conditions and limitations on the number of embryos to be transferred have led to a progressive increase in FT embryo transfer cycles. However, the best solution for endometrial preparation in these cycles is still a matter of debate. In this study, we aimed to review the current methods of endometrial preparation in FT embryo transfer cycles. In light of the current literature, it is hard to determine which method is the best for endometrial preparation. It is therefore necessary to conduct randomized controlled studies in a prospective design, which will also evaluate the above-mentioned factors.

Effect of body mass index and age on in vitro fertilization in polycystic ovary syndrome.

OBJECTIVE: The aim of this study was to investigate age-related variations in the effect of body mass index (BMI) on in vitro fertilization (IVF) outcomes. MATERIAL AND METHODS: This was a cohort study conducted by retrospectively investigating the IVF cycles of 653 polycystic ovary syndrome (PCOS) patients under the age of 40 years who were diagnosed based on the Rotterdam criteria in a private IVF clinic between 2005 and 2015. The study included data from 653 IVF cycles of PCOS patients. The patients were classified into three groups based on their BMI, i.e., normal weight (n=299), overweight (n=208), and obese (n=146). The patients were also grouped by age: 562 patients were under the age of 35 years and 91 patients were above the age of 35 years. Then, BMI- and age-related variations in the IVF cycle parameters and clinical pregnancy rates of patients with PCOS were investigated. The Mantel-Haenszel Chi-square statistical assessment method was used to determine whether the effect of BMI on IVF outcomes varies with age. RESULTS: Variations in cycle variables with BMI and age showed that IVF cycles were negatively affected by increases in obesity and age. Clinical pregnancy rates were found to be lower in the obese group than in the other groups, particularly in the age group above 35 years; however, this difference could not be proven statistically. CONCLUSION: The present study evaluated obesity and clinical pregnancy rates in IVF cycles in PCOS patients according to age groups, and particularly in the obese group, the clinical pregnancy rates were observed to be lower in the age group ≥35 years than in the other BMI groups; however, this difference was found to be statistically insignificant.

Repeated implantation failure: a new potential treatment option.

BACKGROUND: Previous studies have shown that the intrauterine administration of peripheral blood mononuclear cells (PBMC) may improve pregnancy outcome of women with repeated implantation failure (RIF). We have demonstrated that, during implantation, corticotropin-releasing hormone (CRH) plays a key role in facilitating endometrial decidualization and maternal-foetal immunotolerance. In the present preliminary study, we investigated whether the intrauterine administration of autologous CRH-treated PBMC can improve clinical pregnancy rates of women with RIF. METHODS: Forty-five (n = 45) women with at least three failed in vitro fertilization (IVF) attempts and no previously reported clinical pregnancy were included in this crossover study. All women underwent controlled ovarian stimulation using the long GnRH agonist protocol. PBMC were isolated at day of oocyte retrieval, treated with CRH and administered in the uterine cavity at day 2, following oocyte retrieval. Blastocyst transfer was performed on day 5. RESULTS: Following the CRH-PBMC intrauterine administration, a significant increase was observed in the clinical pregnancy rate of this cohort of women with RIF (20/45 women had a clinical pregnancy; 44.44%, P < 10(-3)) compared to the previous null clinical pregnancy rate prior to the intervention. CONCLUSION: The current findings support a possible role for the intrauterine administration of autologous CRH-treated PBMC in treating women with RIF. Further randomized controlled trials are needed to investigate the efficacy of this intervention.

Sequential (hFSH + recFSH) vs homogenous (hFSH or recFSH alone) stimulation: clinical and biochemical (cumulus cell gene expression) aspects.

FSH is a key hormone in the regulation of follicular development. Together with the EGF network, these molecules mediate oocyte maturation and competence in preparation for the action of LH. FSH isoforms regulate distinct biological pathways and have specific effects on granulosa cell function and maturation of the ovarian follicle. Their dynamic interactions occur during the follicular cycle; short-living forms are predominant in the pre-ovulatory phase, whereas long-acting molecules characterize the luteal-follicular transition. Recombinant FSH (rFSH) molecules have a reduced number of isoforms and are less acidic, with a shorter half-life. We have investigated sequential stimulation, comparing hFSH + rFSH, vs. rFSH alone and hFSH alone for the entire stimulation phase. Sequential stimulation leads to an E2 per MII oocyte ratio that is much lower than is seen during treatment with the two drugs individually. Although there is a positive tendency in favor of the sequential treatment, there was no significant difference in pregnancy rates, even taking frozen embryos into consideration. The cumulus cell transcriptome varies considerably between the treatments, although with no clear significance. When comparing pregnant vs. non-pregnant patients, in general a decrease in mRNA expression can be observed in the pregnant patients, especially in expression of folic acid receptor 1 and ovostatin 2. This indicates that material has been transferred from CC to the oocyte. However, a common observation in the literature is that variations in the transcriptome of the cumulus cells are highly dependent upon the patient genotype; the potential for applying this strategy as a basis for selecting embryos is, at the very least, questionable.

Recurrent implantation failure: definition and management.

Recurrent implantation failure refers to failure to achieve a clinical pregnancy after transfer of at least four good-quality embryos in a minimum of three fresh or frozen cycles in a woman under the age of 40 years. The failure to implant may be a consequence of embryo or uterine factors. Thorough investigations should be carried out to ascertain whether there is any underlying cause of the condition. Ovarian function should be assessed by measurement of antral follicle count, FSH and anti-Mu¨llerian hormone. Increased sperm DNA fragmentation may be a contributory cause. Various uterine pathology including fibroids, endometrial polyps, congenital anomalies and intrauterine adhesions should be excluded by ultrasonography and hysteroscopy. Hydrosalpinges are a recognized cause of implantation failure and should be excluded by hysterosalpingogram; if necessary, laparoscopy should be performed to confirm or refute the diagnosis. Treatment offered should be evidence based, aimed at improving embryo quality or endometrial receptivity. Gamete donation or surrogacy may be necessary if there is no realistic chance of success with further IVF attempts.

Carnitine content in the follicular fluid and expression of the enzymes involved in beta oxidation in oocytes and cumulus cells.

PURPOSE: The purpose of this study is to study lipid metabolism in oocytes and embryos that is a neglected parameter in human IVF. METHODS: We have tested the total carnitine content (TC) in the follicular fluid of 278 patients (217 non pregnant, 61 pregnant) undergoing IVF. RESULTS: The follicular fluid TC is neither correlated with the circulating estradiol content in serum nor with the outcome the IVF attempt. Carnitine, through the carnitine shuttle, is a major partner in lipid beta oxidation, metabolic pathway involved in the acquisition of oocyte competence. The expression of carnitine synthesis enzymes and lipid beta oxidation was studied in cumulus cells collected at the time of ovum retrieval and in oocyte. Surprisingly the expression for carnitine synthesis is not detectable in oocytes whereas the enzymes involved in lipid beta oxidation are rather strongly expressed. CONCLUSIONS: The addition of carnitine in oocyte maturation and embryo culture media should not be overlooked.

Globozoospermia is mainly due to DPY19L2 deletion via non-allelic homologous recombination involving two recombination hotspots.

To date, mutations in two genes, SPATA16 and DPY19L2, have been identified as responsible for a severe teratozoospermia, namely globozoospermia. The two initial descriptions of the DPY19L2 deletion lead to a very different rate of occurrence of this mutation among globospermic patients. In order to better estimate the contribution of DPY19L2 in globozoospermia, we screened a larger cohort including 64 globozoospermic patients. Twenty of the new patients were homozygous for the DPY19L2 deletion, and 7 were compound heterozygous for both this deletion and a point mutation. We also identified four additional mutated patients. The final mutation load in our cohort is 66.7% (36 out of 54). Out of 36 mutated patients, 69.4% are homozygous deleted, 19.4% heterozygous composite and 11.1% showed a homozygous point mutation. The mechanism underlying the deletion is a non-allelic homologous recombination (NAHR) between the flanking low-copy repeats. Here, we characterized a total of nine breakpoints for the DPY19L2 NAHR-driven deletion that clustered in two recombination hotspots, both containing direct repeat elements (AluSq2 in hotspot 1, THE1B in hotspot 2). Globozoospermia can be considered as a new genomic disorder. This study confirms that DPY19L2 is the major gene responsible for globozoospermia and enlarges the spectrum of possible mutations in the gene. This is a major finding and should contribute to the development of an efficient molecular diagnosis strategy for globozoospermia.

Intravenous calcium infusion as a novel preventive therapy of ovarian hyperstimulation syndrome for patients with polycystic ovarian syndrome.

OBJECTIVE: To evaluate the effectiveness of IV calcium infusion on prevention of ovarian hyperstimulation syndrome (OHSS) in patients with polycystic ovary syndrome undergoing assisted reproductive techniques cycles. DESIGN: A retrospective comparative study. SETTING: Assisted reproduction techniques centre in Turkey. PATIENT(S): Four hundred fifty-five women with high risk for OHSS. INTERVENTION(S): The patients in group I (n = 84) were administered IV calcium gluconate for prevention of OHSS, and the patients in group II (n = 371) comprised the control group, with no manipulation for prevention of OHSS and were age- and body mass index-matched with the study group. MAIN OUTCOME MEASURE(S): Ovarian hyperstimulation syndrome rate, clinical pregnancy rate. RESULT(S): Mean (±SD) ages of the women in the calcium infusion group (group I) and the control group (group II) were comparable (30.5 ± 4.3 vs. 31.4 ± 3.9, respectively). Ovarian hyperstimulation syndrome was found in 16.2% (60 patients) in group II, whereas in group I, only 3 patients (3.6%) developed OHSS. Interestingly, all the hyperstimulation cases in group I were mild, and there was no severe effect. Implantation rates were similar in both groups. Furthermore, we obtained clinical pregnancy in nearly 40.5% in group I and 28.8% in group II. The live-birth rate was 38.1% in the calcium infusion group and 24.8% in the control group. CONCLUSION(S): Intravenous calcium infusion resulted in a significantly lower rate of development of OHSS for patients with polycystic ovary syndrome and high risk of OHSS. This novel therapy may be used for prevention of OHSS effectively.

Zinc concentrations in serum and follicular fluid during ovarian stimulation and expression of Zn2+ transporters in human oocytes and cumulus cells.

Serum and follicular fluid zinc concentrations were investigated in patients undergoing assisted reproductive treatment. No correlation was found between zinc and oestradiol concentrations in serum. At the time of oocyte retrieval, zinc concentrations in follicular fluid were significantly lower than serum concentrations (P<0.0001). The expression of the two families of zinc transporters, ZnT and ZiP, as well as the metal regulatory transcription factors, MTF1 and 2, and metallothioneins, which are both involved in regulatory aspects of zinc transport, was assayed in cumulus cells and in germinal-vesicle oocytes. Most of the zinc transporters, metallothioneins and metal regulatory transcription factor are expressed in oocytes and not in cumulus cells. This may indicate an important role for zinc, in particular with potential linking to genome stability during early embryonic development. In contrast, cumulus cells seem to be at the end of their life's journey, with weak expression of transcriptional activity linked to cellular housekeeping.