FMR1 and AKT/mTOR Signaling in Human Granulosa Cells: Functional Interaction and Impact on Ovarian Response.

We aimed to determine whether a functional link with impact on female ovarian reserve exists between FMR1 expression and expression ratios of AKT/mTOR signaling genes in human granulosa cells in vivo, as suggested from prior in vitro data. Three hundred and nine women, who were classified as normal (NOR; n = 225) and poor (POR; n = 84) responders based on their ovarian reserve, were recruited during stimulation for assisted reproductive techniques. Expressions of FMR1 and of key genes of the AKT/mTOR and AKT/FOXO1/3 signaling pathways were comparatively analyzed in their granulosa cells. FMR1 expression in granulosa cells of NOR and POR correlated significantly with AKT1, TSC2, mTOR, and S6K expression. No correlation was found between FMR1 and FOXO1 in all, and FOXO3 expression in POR, patients. AKT1 expression was significantly higher and FOXO1 expression lower in POR samples, whereas AKT1 expression was lower and FOXO1 expression was higher in NOR samples. In human native granulosa cells, FMR1 expression significantly correlated with the expression of key genes of the AKT/mTOR signaling pathway, but not with the FOXO1/3 signaling pathway. Our data point to a functional link between FMR1 expression and expression of the AKT/mTOR signaling pathway genes controlling human follicular maturation.

Non-invasive Embryo Assessment: Altered Individual Protein Profile in Spent Culture Media from Embryos Transferred at Day 5.

In order to improve ART outcome, non-invasive embryo assessment is gaining more and more attention. Therefore, the aim of this study is to determine the consecutive implantation potential via the secretome between blastocysts with or without implantation and to analyse possible interactions between these differentially expressed proteins. In this prospective study, 69 spent culture media from blastocysts transferred at day 5 were collected from patients undergoing IVF/ICSI treatment in a single IVF centre between April 2015 and November 2018 after informed consent and analysed individually. Exclusion criteria were the absence of informed consent, PCOS, endometriosis and maternal age > 42 years. Dependent on the treatment outcome, media were subsequently divided into two groups: from embryos who implanted successfully (n = 37) and from embryos without implantation (n = 32). Ninety-two proteins were measured simultaneously using the proximity extension assay (PEA) technology with the Olink® CVD III panel employing oligonucleotide-labelled antibodies. Statistical analysis was performed using the Kolmogorov-Smirnov test, Student's t test, the Mann-Whitney U test and Fisher's exact test. Media from implanted blastocysts showed significantly higher expression of EPHB4, ALCAM, CSTB, BMH, TIMP4, CCL24, SELE, FAS, JAM-A, PON3, PDGF-A, vWF and PECAM-1 compared with media from blastocysts without subsequent implantation. The highest relative expression change could be demonstrated for PECAM-1 and TIMP4. PECAM-1, SELE and vWF were co-expressed. Especially EPHB 4, SELE, ALCAM, MCP-1, CCL24, FAS, JAM-A and PDGF-A have already been described in early embryonic development and metabolism. Therefore, these proteins together with PECAM-1 indicate possible biomarkers for non-invasive embryo assessment in the future. However, due to the innovative methodology, defining a threshold for the use as biomarkers remains to be assessed.

GRN, NOTCH3, FN1, and PINK1 expression in eutopic endometrium - potential biomarkers in the detection of endometriosis - a pilot study.

PURPOSE: Endometriosis (EM) is a common gynecological disease affecting 10-15% of women of reproductive age. However, molecular mechanisms and pathogenesis are still not completely understood. Furthermore, due to the absence of a reliable clinical biomarker, the only viable method for the often-delayed definitive diagnosis is laparoscopic surgery. Our objective was to analyze molecular differences of selected endometrial proteins and genes of women suffering from different stages of EM compared with healthy women to evaluate potential clinical biomarkers. METHODS: We analyzed eutopic endometrial tissue samples from women undergoing a laparoscopic surgery (n = 58). mRNA gene expression of progranulin (GRN), neurogenic locus notch homolog protein (NOTCH3), fibronectin (FN1), and PTEN-induced kinase 1 (PINK1) was analyzed using qRT-PCR. Protein expression was determined using ELISA and immunohistochemistry. RESULTS: Significant differences in gene expression between the different stages of the disease were noted for GRN, NOTCH3, FN1, and PINK1 (p < 0.05). The endometrium of women with minimal EM (ASRM I) showed the highest mRNA expression. Protein levels of GRN and FN1 on the other hand were significantly decreased in the endometrium of women with EM compared with those of healthy controls. Furthermore, for GRN and FN1, we could detect a correlation of protein expression with the severity of the disease. CONCLUSION: Our findings suggest a potential use of GRN and FN1 as clinical biomarkers to detect endometriosis. In addition, GRN, NOTCH3, FN1, and PINK1 could potentially be useful to differentiate between the underlying stages of the disease. However, a validation with a larger study population is needed.

Intraindividual Embryo Morphokinetics Are Not Affected by a Switch of the Ovarian Stimulation Protocol Between GnRH Agonist vs. Antagonist Regimens in Consecutive Cycles.

Background: The impact of controlled ovarian stimulation (COS) during medically assisted reproduction (MAR) on human embryogenesis is still unclear. Therefore, we investigated if early embryonic development is affected by the type of gonadotropin-releasing hormone (GnRH) analog used to prevent a premature LH surge. We compared embryo morphology and morphokinetics between GnRH agonist and antagonist cycles, both involving human chorionic gonadotropin (hCG)-trigger. To reduce possible confounding factors, we used intraindividual comparison of embryo morphokinetics in consecutive treatment cycles of the same patients that underwent a switch in the COS protocol. Methods: This retrospective cohort study analyzed morphokinetics of embryos from patients (n = 49) undergoing a switch in COS protocols between GnRH agonists followed by GnRH antagonists, or vice versa, after culture in a time-lapse incubator (EmbryoScope®, Vitrolife) in our clinic between 06/2011 and 11/2016 (n = 49 GnRH agonist cycles with n = 172 embryos; n = 49 GnRH antagonist cycles with n = 163 embryos). Among time-lapse cycles we included all embryos of the two consecutive cycles before and after a switch in the type of COS in the same patient. In-vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) was performed and embryos were imaged up to day 5. Data were analyzed using Mann-Whitney U test or Fisher's exact test. The significance level was set to p = 0.05. Patients with preimplantation genetic screening cycles were excluded. Results: The mean age (years ± standard deviation) of patients at the time of treatment was 35.7 ± 4.3 (GnRH agonist) and 35.8 ± 4.0 (GnRH antagonist) (p = 0.94). There was no statistically significant difference in the number of oocytes collected or the fertilization rate. The numbers of top quality embryos (TQE), good-quality embryos (GQE), or poor-quality embryos (PQE) were also not different in GnRH agonist vs. antagonist cycles. We found no statistically significant difference between the analyzed morphokinetic parameters between the study groups. Conclusions: Our finding supports the flexible use of GnRH analogs to optimize patient treatment for COS without affecting embryo morphokinetics.

Endometrial expression of receptivity markers subject to ovulation induction agents.

PURPOSE: Implantation rates differ according to ovulation induction agents in ART. This study investigates the different local endometrial effects of LH- versus hCG-induced ovulation. METHODS: Endometrial stromal cells from healthy patients were cultured with hCG or LH in different concentrations, supplemented with 250 ng/mL hCG and progesterone after 2 and 5 days. In addition after decidualization induction, cells were treated with hCG (50 or 250 ng/mL) or LH (10 or 50 ng/mL) for 3 days. Receptivity markers expression was evaluated by real-time quantitative PCR on day 3 and 6. RESULTS: On day 3, non-decidualized cells treated with LH showed an increased expression of IGFBP1, IL-8 and CXCL12 compared to hCG. The expression pattern changed on day 6, where cells treated with hCG showed higher expression of implantation markers compared to LH-treated cells. Furthermore, on day 3, decidualized cells treated with hCG250 showed an increased IL8 and CXCL12 expression compared to LH10. CONCLUSIONS: LH seems to modulate the local endometrial expression of receptivity markers earlier compared to hCG; however, the effect is not sustained over time in cells without prior decidualization. Though, in decidualized cells, pattern changed and an earlier positive effect of hCG was shown on IL-8 and CXCL12.

Exam preparatory course for the 2nd part of the German medical examination in obstetrics and gynecology - a potential tool for the recruitment of new residents during the occupational decision process before the practical year?

BACKGROUND: The "Second Stage of the Physician Exam" at the end of the 5th year of medical school in Germany is the final step before the "Practical Year." An exam preparatory class can cover the complete content of Obstetrics and Gynecology (OB/GYN) in two days. We raise the question of whether such training might promote students' interest in the given specialty during occupational decision making and whether it could even be used by hospitals as a recruitment tool. This investigation is even more important in the context of fierce competition among young professionals at clinics and in different specialties. METHODS: We conducted a multimodal course evaluation for four exam preparatory courses (each of which lasted two days and involved 8.5 h of teaching), including pre- and post-course tests with 20 multiple-choice questions to quantify the level of skill gain. Additionally, a standardized evaluation of course satisfaction was performed, followed by a post-exam questionnaire that dealt with studying activities and individual professional objectives. RESULTS: Overall, n = 197 students took part in four identical courses. Among them, n = 121 completed the pre-/post-course tests, n = 170 completed the evaluation, and n = 110 completed the post-exam questionnaire. An average improvement from 13.9 to 17.2 correct answers was observed (max. 20; pre-/post-difference 95%-CI: [2.77; 3.86], t-test: p < 0.0001). By trend, the students noted that course participation positively influenced their later choice of specialty training (m = 3.63; scale 1 = "strongly disagree," 5 = "strongly agree"). CONCLUSIONS: In addition to self-studying, condensed classroom training is effective and reasonable and might also increase the attractivity of OB/GYN among students and have a positive effect on recruitment.

Cytokines in relation to hCG are significantly altered in asymptomatic women with miscarriage - a pilot study.

BACKGROUND: Spontaneous abortion is one of the most common complications in early pregnancy. A preventive test to identify women who will experience a miscarriage, even before first symptoms occur, is not established. Activation of maternal immunological tolerance seems to be essential for early fetal development and various cytokines have been described in different stages of pregnancy. Therefore, we aimed to investigate if chemokine levels at the time of pregnancy testing relative to human Choriogonadotropin (hCG) are altered in patients who will experience a miscarriage in this pregnancy. METHODS: We obtained blood samples from 39 women. Dependent on the follow-up, patients with a positive pregnancy test were subsequently divided in two groups: ongoing pregnancy (n = 22) and miscarriage (n = 17) in this pregnancy. Immunological and endocrine profiling of maternal plasma at the time of pregnancy testing (5th week of gestation) was performed for each group at the time of pregnancy test using Multiplex and ELISA analysis. RESULTS: hCG was significantly decreased in patients with abortion whereas levels of IL-1ra, MIP-1a and TNF-alpha were significantly increased. GCSF/ IL-1ra-ratio was 1.66-fold increased in patients with ongoing pregnancy. TGF-beta /MIP1a-ratio was significantly 3.45-times higher in patients with miscarriage. Comparing patients with ongoing pregnancy to patients experiencing a miscarriage, we could demonstrate significant alterations of the ratios MIP1a/hCG, IL-1ra/hCG, TNFalpha/hCG, MCP1/hCG, IL-6/hCG, TPO/hCG and TGF-beta1/hCG. The strongest effects were seen for the ratio MIP1a/hCG, IL-1ra/hCG and TNFalpha/hCG. CONCLUSIONS: We have shown that cytokines in relation to hCG after 4 weeks of gestation are significantly altered in women with miscarriage, promising potential as a prognostic biomarker.

FMR1 expression in human granulosa cells increases with exon 1 CGG repeat length depending on ovarian reserve.

BACKGROUND: Fragile-X-Mental-Retardation-1- (FMR1)-gene is supposed to be a key gene for ovarian reserve and folliculogenesis. It contains in its 5'-UTR a triplet-base-repeat (CGG), that varies between 26 and 34 in general population. CGG-repeat-lengths with 55-200 repeats (pre-mutation = PM) show instable heredity with a tendency to increase and are associated with premature-ovarian-insufficiency or failure (POI/POF) in about 20%. FMR1-mRNA-expression in leucocytes and granulosa cells (GCs) increases with CGG-repeat-length in PM-carriers, but variable FMR1-expression profiles were also described in women with POI without PM-FMR1 repeat-length. Additionally, associations between low numbers of retrieved oocytes and elevated FMR1-expression levels have been shown in GCs of females with mid-range PM-CGG-repeats without POI. Effects of FMR1-repeat-lengths-deviations (n < 26 or n > 34) below the PM range (n < 55) on ovarian reserve and response to ovarian stimulation remain controversial. METHODS: We enrolled 229 women undergoing controlled ovarian hyperstimulation for IVF/ICSI-treatment and devided them in three ovarian-response-subgroups: Poor responder (POR) after Bologna Criteria, polycystic ovary syndrome (PCO) after Rotterdam Criteria, or normal responder (NOR, control group). Subjects were subdivided into six genotypes according to their be-allelic CGG-repeat length. FMR1-CGG-repeat-length was determined using ALF-express-DNA-sequencer or ABI 3100/3130 × 1-sequencer. mRNA was extracted from GCs after follicular aspiration and quantitative FMR1-expression was determined using specific TaqMan-Assay and applying the ΔΔCT method. Kruskall-Wallis-Test or ANOVA were used for simple comparison between ovarian reserve (NOR, POR or PCO) and CGG-subgroups or cohort demographic data. All statistical analysis were performed with SPSS and statistical significance was set at p ≤ 0.05. RESULTS: A statistically significant increase in FMR1-mRNA-expression-levels was detected in GCs of PORs with heterozygous normal/low-CGG-repeat-length compared with other genotypes (p = 0.044). CONCLUSION: Female ovarian response may be negatively affected by low CGG-alleles during stimulation. In addition, due to a low-allele-effect, folliculogenesis may be impaired already prior to stimulation leading to diminished ovarian reserve and poor ovarian response. A better understanding of FMR1 expression-regulation in GCs may help to elucidate pathomechanisms of folliculogenesis disorders and to develop risk-adjusted treatments for IVF/ICSI-therapy. Herewith FMR1-genotyping potentially provides a better estimatation of treatment outcome and allows the optimal adaptation of stimulation protocols in future.

Tocolysis with the ß2-sympathomimetic fenoterol does not increase the occurrence of infantile hemangioma in preterm and term infants.

PURPOSE: ß2-sympathomimetics are used in obstetrics as tocolytic agents, despite a remarkable profile of side effects. Recently, the ß2-sympathomimetic tocolytic drug hexoprenaline was identified as an independent risk factor for the development of infantile hemangioma (IH) in preterm infants. The aim of this study was to evaluate whether this observed effect was applicable to other ß2-mimetic tocolytic agents like fenoterol. METHODS: Clinical prospectively collected data of all infants born between 2001 and 2012 and admitted to the neonatal intensive care unit (NICU) at Heidelberg University Hospital and respective maternal data were merged. For the current retrospective cohort study, cases (IH) were matched to controls (no IH) at a ratio of 1:4, adjusting for birth weight, gestational age, gender and multiple gestations. Prenatal exposure to fenoterol and perinatal outcome were analyzed in the total cohort and in subgroups. RESULTS: N = 5070 infants were admitted to our neonatal department, out of which n = 172 infants with IH were identified and compared to n = 596 matched controls. Exposure to fenoterol was not associated with a higher rate of IH in the total matched population (OR 0.926, 95% CI 0.619-1.384) or in a subgroup of neonates < 32 weeks of gestation or with a birth weight < 1500 g (OR 1.127, 95% CI 0.709-1.791). In the total matched population, prenatal exposure to glucocorticoids was associated with a reduced occurrence of IH (OR 0.566, 95% CI 0.332-0.964) and neonates with IH showed a prolonged total hospital stay compared to controls (69 vs. 57 days, p = 0.0033). Known risk factors for IH were confirmed by our large study cohort and included female gender, low birth weight, preterm birth and multiple gestations (all p < 0.005). CONCLUSIONS: Exposure to fenoterol during pregnancy does not increase the occurrence of IH. Further studies are needed to explore differences in the risk profiles of different ß2-sympathomimetic tocolytic drugs.

Plausibility of Menstrual Cycle Apps Claiming to Support Conception.

The interval of peak fertility during the menstrual cycle is of limited duration, and the day of ovulation varies, even in women with fairly regular cycles. Therefore, menstrual cycle apps identifying the "fertile window" for women trying to conceive must be quite precise. A deviation of a few days may lead the couple to focus on less- or non-fertile days for sexual intercourse and thus may be worse than random intercourse. The aim of the present investigation was to develop a scoring system for rating available apps for determining the fertile window and secondarily pilot test 12 apps currently available in both German and English (consisting of 6 calendar-based apps: Clue Menstruations- und Zykluskalender, Flo Menstruationskalender, Maya-Mein Periodentracker, Menstruationskalender Pro, Period Tracker Deluxe, and WomanLog-Pro-Kalender; 2 calculothermal apps: Ovy and Natural Cycles; and 4 symptothermal apps: myNFP, Lady Cycle, Lily, and OvuView). The calendar-based apps were investigated by entering several series of cycles with varying lengths, whereas the symptom-based apps were examined by entering data of cycles with known temperature rise, cervical mucus pattern, and clinical ovulation. The main criteria for evaluating the cycle apps were as follows: (1) What methods/parameters were used to determine the fertile window? (2) What study results exist concerning that underlying method/parameters? (3) What study results exist concerning the app itself? (4) Was there a qualified counseling service? The calendar-based apps predicted the fertile days based on data of previous cycles. They obtained zero points in our scoring system, as they did not comply with any of the evaluated criteria. Calculothermal apps had similar deficits for predicting the most fertile days and produced suboptimal results (Ovy 3/30 points and Natural Cycles 2/30 points). The symptothermal apps determined the fertile days based on parameters of the current cycle: Lady Cycle scored 20/30 points, myNFP 20/30 points, Lily 19/30 points, and OvuView 11/30 points. We concluded that the available cycle apps vary according to their underlying scientific quality and clear rating criteria have been suggested. Three of the tested apps were judged to be eligible for further study. The scientific evaluation of cycle apps depends on good prospective studies undertaken by independent investigators who are free of commercial bias.

Serum levels of Pentraxin 3 differ significantly at the time of blastocyst transfer depending on implantation success: a pilot study.

OBJECTIVE: Many approaches try to identify the underlying molecular mechanisms to detect new potential biomarkers for successful artificial reproductive therapies. One factor has been described as a possible regulator of inflammation during implantation: Pentraxin 3 (PTX3), which seems to be essential for female fertility on one hand, but whose overexpression has been described in many obstetric complications based on abnormal placentation on the other hand. Therefore, we investigated if serum levels of PTX3 at the time of embryo transfer differ between women with an ongoing pregnancy compared to those without implantation. METHODS/DESIGN: During in vitro fertilization cycles of 51 patients, PTX3 levels at the time of embryo transfer were compared between patients without implantation (n = 26) and those with ongoing pregnancy (n = 25) using an enzyme-linked immunosorbent assay. Statistical analysis was performed using the Kolmogorov-Smirnov test, Fisher's exact test and Student's t test RESULTS: No significant differences were found concerning possible confounders (patients age, smoking pattern, embryo quality, number of embryos transferred and prior IVF attempts). Patients without implantation presented with significantly higher serum levels of PTX3 at the time of embryo transfer compared to women who became pregnant (0.781 ± 0.074 ng/ml vs. 0.578 ± 0.055 ng/ml, p < 0.05). CONCLUSIONS: PTX3 could present as a possible biomarker for ART success. The main limitation of this pilot study is its small sample size that needs validation with a larger study population.

Relative Morphokinetics Assessed by Time-Lapse Imaging Are Altered in Embryos From Patients With Endometriosis.

INTRODUCTION: Time-lapse technology allows almost continuous noninvasive assessment of embryonic development. It was shown previously that relative kinetics defining cleavage synchronicity are better predictors of blastocyst quality than absolute time points. This study aims to compare relative kinetics in embryos from patients with and without endometriosis. METHODS: Time-lapse data were collected retrospectively from 596 patients undergoing infertility treatment for in vitro fertilization from January 2011 to July 2016. Four hundred twenty-eight patients with confounding comorbidities (ie, polycystic ovary syndrome, pathological spermiogram in the included cycle, numerical/structural genetic abnormalities, preimplantation genetic screening performed) or incomplete data sets were excluded. Of the 168 included patients, 72 (42.9%) had endometriosis. Indications for in vitro fertilization of controls were tubal factor, unexplained infertility, or prolonged infertility. Relative kinetics were calculated as defined previously: cleavage synchronicity (CS)2-8=((t3-t2) + (t5-t4))/(t8-t2), CS4-8=(t8-t5)/(t8-t4), CS2-4=(t4-t3)/(t4-t2), DNA replication time ratio (DR)=(t3-t2)/(t5-t3). In women with more than one embryo, the median time was analyzed. RESULTS: Median age, body mass index, smoking status, and AMH levels were similar in both groups. Embryos from patients with endometriosis showed poorer relative kinetics. The relative time CS2-8 was decreased in embryos from patients with endometriosis (0.7 [0.0-0.93] vs 0.8 [0.0-0.94], P < .05) and CS4-8 was increased (0.4 [0.0-1.0] vs 0.3 [0.0-1.0], P < .05). The less powerful diagnostic relative kinetic parameters (CS2-4 and DR) were not significantly different. CONCLUSIONS: Embryos from patients with endometriosis presented with altered relative kinetics suggesting poorer embryo quality. These findings support recently published data demonstrating reduced oocyte quality in patients with endometriosis which is one possible explanation for their poor response to fertility treatment.

Altered miRNA-profile dependent on ART outcome in early pregnancy targets Wnt-pathway.

Main goal of this study is to detect the possible alterations in microRNA (miRNA) expression and the pathway targeted in plasma at the time of embryo transfer and pregnancy testing dependent on the assisted reproductive treatment (ART) outcome after ovarian hyperstimulation for in vitro fertilization. Changes in miRNA expression in plasma of women, who became pregnant (n = 6) vs women who failed implantation (n = 6) following day 5 embryo transfer (ET), were investigated at the day of ET and pregnancy testing (PT). Protein expression to validate the finding was performed with a sample size of n = 20 (10 per group) using enzyme-linked immunosorbent assay. Enriched Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed using DIANA-miRPath, v3.0 software based on predicted targets by DIANA-microT-CDS. 4 miRNAs could be identified as possible biomarkers for implantation success. The 11 miRNAs showing the highest significant alterations were all associated with the regulation of WNT3 and WNT7a. While WNT7a presented with a significant decrease between ET and PT in case of ongoing pregnancy, women with implantation failure showed unaltered concentrations. WNT3 presented with a significant decrease in both groups. However, the loss of WNT3 between ET and PT was significantly higher in patients who became pregnant. Main limitation of this prospective study is its small sample size, defining it as a pilot analysis. To conclude, we could demonstrate a significant change in miRNA profile dependent on the ART outcome affecting Wnt pathway. Our findings indicate a possible prospective use of miRNA as biomarkers for implantation success.

Effects of a hyperandrogenaemic state on the proliferation and decidualization potential in human endometrial stromal cells.

OBJECTIVE: Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women, involving hyperandrogenaemia and insulin resistance. Treatment options include dexamethasone, as well as the off-label use of metformin. To evaluate the impact of those drugs on cyclic changes in endometrial development, we tested possible effects of metformin and dexamethasone on endometrial stromal cells decidualisation, proliferation, and gene regulation in a hyperandrogenaemic microenvironment in vitro. METHODS/DESIGN: Ten endometrial biopsies (of which five were decidualized in vitro) were used from regularly cycling women. Cells were treated with testosterone, dexamethasone, and metformin in different concentrations. Thereafter, cells were assessed for proliferation and decidualization capacity, as well as mTor and MMP-2 gene regulation. RESULTS: Metformin showed a dose-dependent negative effect on prolactin secretion, a known decidualization marker. This effect was stronger in a hyperandrogenaemic condition and could not be compensated by dexamethasone. Testosterone had a dose dependent negative effect on proliferation in decidualized endometrial stromal cells. Dexamethasone slightly compensated the negative proliferative effect only in low-dose testosterone. High-dose metformin also showed a dose-dependent reduction in endometrial stromal cell proliferation without a major impact by testosterone or dexamethasone in decidualized and non-decidualized cells. High-dose metformin significantly reduced the expression of matrix metalloproteinase-2 (MMP-2) and mechanistic Target of Rapamycin (mTor), regardless of the concentration of dexamethasone and testosterone. The strongest effect could be observed for the combination with high-dose dexamethasone. CONCLUSION: When therapies, such as metformin and dexamethasone, are used to normalize peripheral androgen levels in patients with PCOS, their effect on the endometrial microenvironment should be taken into consideration as well, especially metformin has to be used with caution because of its dose dependent, possibly inhibiting effect at the endometrial proliferation.