Vascular Health of Females with History of Assisted Reproductive Technology

The use of assisted reproductive technologies (ART) for the treatment of infertility is gaining popularity. Limited data on the overall vascular health of females with history of ART are available. This pilot study aimed to investigate the overall vascular health of females with history of ART compared to individuals who conceived spontaneously. The assessment of overall vascular health included the measurement of brachial blood pressure, central blood pressure, and pulse wave velocity, as well as the evaluation of the arterial stiffness and carotid intima-media thickness (cIMT) of the common carotid arteries. Conventional blood lipids including lipoprotein a (Lp(a)) were also determined. In total, 45 females with history of ART and 52 females who conceived spontaneously were included (mean age: 47.72 ± 5.96 years vs. 46.84 ± 7.43 years, p = 0.525). An initial comparison revealed a significantly higher prevalence of elevated Lp(a) in ART females (p = 0.011). However, after multiple comparison correction, the significant result disappeared (p = 0.132). Within the cohort of ART females, no significantly higher cardiovascular risk was detected regarding vascular function. The potentially higher prevalence of elevated Lp(a) in ART females must be further investigated in future studies, as it might contribute to the impaired reproductive process in this cohort.

Vascular function in a cohort of children, adolescents and young adults conceived through assisted reproductive technologies-results from the Munich heARTerY-study

Background

Over 8 million individuals worldwide have been conceived through assisted reproductive technologies (ART). There is conflicting evidence on the cardiovascular health of ART offspring. This study aimed to investigate vascular function in a cohort of children, adolescents and young adults conceived through ART compared to spontaneously conceived peers.

Methods

Anthropometric variables, diet quality, level of physical activity and sedentary behavior were assessed. An extensive evaluation of vascular function was conducted. Blood pressure as well as endothelial function were evaluated. Carotid intima-media thickness was recorded sonographically. Blood draws were taken to determine blood lipids as well as HbA1c.

Results

In total, 66 ART subjects conceived through in vitro fertilization (IVF) or intracytoplasmic sperm injection and 86 spontaneously conceived peers were included in this observational cohort study. Both groups were similar in age [11.31 (8.10-18.00) vs. 11.85 (8.72-18.27) years, P=0.373]. ART subjects displayed a significantly higher body fat percentage [19.30% (15.80-26.02%) vs. 15.91% (13.21-21.00%), P=0.007]. Both groups did not differ significantly in diet quality, physical activity, sedentary behavior, and vascular function. Blood lipids and HbA1c were comparable between both groups. ART subjects showed significantly lower levels of triglycerides compared to spontaneously conceived peers. The prevalence of lipoprotein (a) [Lp(a)] ≥50 mg/dL tended to be higher within the ART cohort. Vascular function did not deteriorate more profoundly with age in ART subjects than in spontaneously conceived peers.

Conclusions

The results of the current study do not indicate a significantly lower vascular function in a cohort of children, adolescents and young adults conceived through ART compared to spontaneously conceived peers. Future studies should address the prevalence of elevated Lp(a) levels in infertile individuals who sought ART treatment. In addition, more studies evaluating body fat percentage as well as cardiovascular morbidity in adult ART subjects are required. For a more precise cardiovascular risk stratification, multi-center studies with larger ART sample sizes, preferably at adult age, are required in the future.

Left ventricular systolic function in subjects conceived through assisted reproductive technologies

Background

Over the past decades, assisted reproductive technologies (ART) have gained remarkable influence in the treatment of infertility and account for more than 2 % of births in European countries nowadays. Accumulating evidence suggests ART to cause cardiovascular alterations, including left ventricular (LV) dysfunctions, within its offspring. The aim of this study was to assess LV systolic function in subjects conceived through ART in comparison to spontaneously conceived peers.

Methods

For the assessment of LV morphology and LV function, M-Mode echocardiography, pulsed wave Doppler and two-dimensional speckle tracking echocardiography (2DSTE) were applied. LV ejection fraction (EF) and fractional shortening (FS) were assessed in M-Mode and calculated by Teichholz formula. EF was additionally assessed semiautomatically through 2DSTE.

Results

In total, 64 ART subjects and 83 spontaneously conceived controls with no significant differences in age (12.52 ± 5.64 years vs. 13.20 ± 5.95 years, p = 0.486) and sex were included in the analysis. In the ART cohort, significantly lower values were observed for M-Mode assessed EF (63.63 ± 5.17 % vs. 65.35 ± 5.10 %, p = 0.046) and FS (34.26 ± 3.87 % vs. 35.60 ± 3.84 %, p = 0.038). However, after the adjustment for birth weight percentile and gestational age, M-Mode assessed EF and FS displayed no significant differences between both groups. LV morphology and remaining systolic function parameters, such as mitral annular plane systolic excursion, aortic velocity time integral, global peak longitudinal strain and 2DSTE measured EF, were comparable between both groups.

Conclusion

This study suggests a lower LV systolic function in ART subjects, visualized by significantly lower values for M-Mode assessed EF and FS, compared to spontaneously conceived peers. The clinical relevance of these findings has to be investigated as the above-mentioned parameters were in normal reference range. In addition, LV systolic function parameters evaluated by other echocardiographic imaging modalities were comparable between both groups. Therefore, further studies will be required to evaluate the influence of ART on LV systolic function and cardiovascular morbidity in the future.

Recurrent Miscarriage: Diagnostic and Therapeutic Procedures. Guideline of the DGGG, OEGGG and SGGG (S2k-Level, AWMF Registry No. 015/050, May 2022)

Purpose The aim of this guideline is to standardize the diagnosis and therapy of recurrent miscarriage (RM) using evidence from the recent literature. This is done by using consistent definitions, objective evaluations and standardized treatment protocols.

Methods When this guideline was compiled, special consideration was given to previous recommendations in prior versions of this guideline and the recommendations of the European Society of Human Reproduction and Embryology, the Royal College of Obstetricians and Gynecologists, the American College of Obstetricians and Gynecologists and the American Society for Reproductive Medicine, and a detailed individual search of the literature about the different topics was carried out.

Recommendations Recommendations about the diagnostic and therapeutic procedures offered to couples with RM were developed based on the international literature. Special attention was paid to known risk factors such as chromosomal, anatomical, endocrinological, physiological coagulation, psychological, infectious and immune disorders. Recommendations were also developed for those cases where investigations are unable to find any abnormality (idiopathic RM).

Vascular Health in Adults Born After Using Assisted Reproductive Technologies

An increasing number of children are conceived by assisted reproductive technologies (ART). Several studies indicated vascular alterations in ART children. However, limited data is available within the adult ART population. Therefore, this study investigated the overall vascular health of young ART adults in comparison to spontaneously conceived peers. In total, 16 ART subjects and 22 spontaneously conceived peers (22.06 ± 2.21 years vs. 22.00 ± 2.14 years, p = 0.194) were enrolled for the assessment of endothelial function, brachial blood pressure, central blood pressure, pulse wave velocity, carotid intima-media thickness, and blood lipids. No significant differences in vascular function were detected between the in vitro fertilization subgroup (n = 9), the intracytoplasmic sperm injection subgroup (n = 7) and spontaneously conceived peers. This pilot study suggests an unimpaired vascular function in young ART adults. In the future, multi-centric studies with a greater sample size are required to confirm the results of the current study and enable precise cardiovascular risk stratification of the adult ART population.

Seasonal dynamic of cholecalciferol (D3) and anti-Muellerian hormone (AMH) with impact on ovarian response and IVF/ICSI

OBJECTIVE

Recent studies revealed intriguing associations between cholecalciferol (D3) and reproductive functions. Seasonal changes of D3 concentrations are well known; however, they are not always considered in the context of reproductive functions. In this study, we analyzed D3 serum concentration in IVF/ICSI patients with respect to seasonal 3-month quartiles and anti-Muellerian hormone (AMH) referring to the impact on Assisted Reproductive Technologies (ART) outcome.

MATERIALS AND RESEARCH METHODS

We studied 469 female patients, presenting between 2012 and 2018 for ART treatment in our fertility center. D3 as well as the AMH serum concentrations were measured at the beginning of the follicle stimulation (days 3-5 of menstrual cycles). Results were evaluated with respect to seasonal quartiles and outcome of the ART cycles.

RESULTS

D3 concentrations showed significant fluctuations within annual quartiles with a pronounced peak in August-October and a minimum in February-April (26.0 vs. 20.5 mg/dl; p < 0.0001). Similar seasonal dynamics were found for AMH (2.98 vs. 1.78 ng/ml; p = 0.010) and these were associated with significantly shorter stimulation periods during August-October (11.29 vs. 12.12 days; p = 0.042), higher number of fertilized oocytes between August and October (6.23 vs. 4.97; p = 0.05) along with a trend towards higher numbers of cumulus-oocyte complexes. However, no such differences were found for the numbers of MII oocytes or pregnancy rates.

CONCLUSION

Our data indicate seasonal 3-month quartile variations of AMH concentrations and characteristics of ART, such as days of ovarian stimulation and number of fertilized oocytes. Highest AMH concentrations were found between August and October and this quartile was associated with highest D3 concentrations.

Effects of intralipid infusions on anti-trophoblast antibody (ATAb)-activities in patients with recurrent pregnancy loss: An observational report

PROBLEM

Some studies suggest intravenous intralipid infusions (IVIL) to be effective in the treatment of immune-mediated pregnancy failure. To this date it remains to be established, how IVIL might protect pregnancy and therefore a specific subgroup of RPL patients that might benefit from IVIL has not been defined. Anti-trophoblast antibodies (ATAb) have been associated with RPL and appear to mediate immune pathology. We have shown, that ATAb in vitro decrease HCG- and progesterone production pointing to a mechanism how ATAb interfere with normal pregnancies. We have measured ATAb-activities in patients undergoing off label IVIL-treatment.

METHOD OF STUDY

Ten RPL-patients with positive ATAb, determined by using the choriocarcinoma cellline JEG-3 and flow cytometry as described before, and otherwise unexplained RPL, received off-label IVIL during pregnancy. Two ATAb-positive RPL patients preferred expectant management. In addition, ATAb-activity was studied in pregnancies of two healthy ATAb-negative volunteers without miscarriages.

RESULTS

In RPL patients receiving IVIL, relative ATAb-activity decreased from an average of 56.8±17.0% to 20.8±11.0% (P < .001). The two RPL-patients without IVIL, aborted at 6+3gw and 7+4gw and embryonic genetic testing revealed euploid karyotypes. During pregnancies of the two healthy ATAb-negative individuals, ATAb-activities remained negative (16±9.8%) without significant changes (P = .22). Nine of the 10 pregnancies receiving IVIL proceeded uneventful with healthy newborns ≥37gw. One patient receiving IVIL aborted at 7+6gw and embryonic genetic-testing revealed a trisomy 16. No specific side effects concerning IVIL were noted.

CONCLUSIONS

Intralipid preparations during pregnancies of ATAb-positive RPL-patients significantly reduce ATAb-activities and this may indicate a therapeutic mechanism of IVIL.

Epigenetic changes occur in placentas of spontaneous and recurrent miscarriages

BACKGROUND

In contrast to genetic abnormalities which are well known to be responsible for around 50 % of human miscarriages, there is very few data about epigenetic alterations in spontaneous and recurrent miscarriages (SM, RM). The aim of this study was to analyze the histone modification marks H3K9ac and H3K4me3 in SM and RM.

METHODS

The abundance of histone modifications H3K4me3/H3K9ac was analyzed by western blot in frozen abortion material of SM and RM compared to a control group of legal pregnancy terminations. Further, to characterize placental tissue cells expressing H3K4me3/H3K9ac immunohistochemistry (IHC) and immunofluorescence was performed in 20 SM, 19 RM and 26 controls.

RESULTS

The western blot data showed a tendency to an overall reduction of H3K4me3/H3K9ac, in the placental tissue of particularly SM. Further we differentiated between syncytiotrophoblast, cytotrophoblast and decidual cells and found a significant decrease of H3K4me3 in SM in cytotrophoblast cells and syncytial stroma. In RM H3K4me3 was downregulated exclusively in the syncytiotrophoblast. H3K9ac was reduced in SM and RM in all evaluated compartments, except from the syncytiotrophoblast.

CONCLUSION

Our study showed an overall reduced histone modification of H3K4me3 and H3K9ac in the placental tissue of SM. Concerning RM, particularly the reduction of H3K9ac was detected in the placental tissue, indicating that RM group has distinct profile in epigenetic regulation. Whether these histone modifications are part of a possible pathophysiologic cascade during SM and RM or are merely indicating a defective placentation, cannot be concluded from this study.

Effects of controlled ovarian stimulation on vascular barrier and endothelial glycocalyx: a pilot study

Purpose

Controlled ovarian stimulation significantly amplifies the number of maturing and ovulated follicles as well as ovarian steroid production. The ovarian hyperstimulation syndrome (OHSS) increases capillary permeability and fluid extravasation. Vascular integrity intensely is regulated by an endothelial glycocalyx (EGX) and we have shown that ovulatory cycles are associated with shedding of EGX components. This study investigates if controlled ovarian stimulation impacts on the integrity of the endothelial glycocalyx as this might explain key pathomechanisms of the OHSS.

Methods

Serum levels of endothelial glycocalyx components of infertility patients (n=18) undergoing controlled ovarian stimulation were compared to a control group of healthy women with regular ovulatory cycles (n=17).

Results

Patients during luteal phases of controlled ovarian stimulation cycles as compared to normal ovulatory cycles showed significantly increased Syndecan-1 serum concentrations (12.6 ng/ml 6.11^25th–19.13^75th to 13.9 ng/ml 9.6^25th–28.9^75th; p=0.026), indicating shedding and degradation of the EGX.

Conclusion

A shedding of EGX components during ovarian stimulation has not yet been described. Our study suggests that ovarian stimulation may affect the integrity of the endothelial surface layer and increasing vascular permeability. This could explain key features of the OHSS and provide new ways of prevention of this serious condition of assisted reproduction.

Maternal and paternal carriage of the annexin A5 M2 haplotype: a possible risk factor for recurrent implantation failure (RIF)

OBJECTIVE

This study was carried out to determine the potential role of the M2/ANXA5 haplotype as a risk factor for recurrent implantation failure (RIF). Carriage of the M2/ANXA5 haplotype that induces prothrombotic changes has been implicated in failure of early pregnancies and placenta-mediated complications (preeclampsia, IUGR, preterm birth).

MATERIAL AND METHODS

In the present case control study, 63 couples (females and males) with RIF presenting for IVF/ICSI to the Fertility Center of [masked] were analyzed. RIF was defined as ≥ 4 consecutive failed ART-transfers of ≥ 4 blastocysts or ≥ 8 cleavage-stage embryos of optimal quality and maternal age ≤ 41. Fertile female controls (n = 90) were recruited from the same center. Population controls (n = 533) were drafted from the PopGen biobank, UKSH Kiel.

RESULTS

Couples carrying the M2/ANXA5 haplotype turned out to have a significantly increased relative risk (RR) for RIF. Compared with female fertile controls, RR was 1.81 with p = 0.037 (OR 2.1, 95%CI 1.0-4.3) and RR was 1.70, with p = 0.004 (OR 2.0, 95%CI 1.2-3.1) compared with population controls (15.4% M2 carriers). Male partners were comparable with RIF females for M2/ANXA5 haplotypes (28.6% vs. 23.8%, p = 0.54). RIF females compared with population controls had a RR of 1.55 (p = 0.09) and RIF males compared with population controls had a RR of 1.9 (p = 0.01). Couples with ≥ 7 failed transfers showed a RR of 1.82 (p = 0.02) compared with population controls.

CONCLUSION

Our findings suggest that maternal as well as paternal M2/ANXA5 haplotype carriages are risk factors for RIF. These results allow new insights into the pathogenesis of RIF and might help to identify relevant risk groups.

Diagnosis and Therapy Before Assisted Reproductive Treatments. Guideline of the DGGG, OEGGG and SGGG (S2k Level, AWMF Register Number 015-085, February 2019) - Part 1, Basic Assessment of the Woman

Introduction Supporting and counselling couples with fertility issues prior to starting ART is a multidisciplinary diagnostic and therapeutic challenge. The first German/Austrian/Swiss interdisciplinary S2k guideline on "Diagnosis and Therapy Before Assisted Reproductive Treatments (ART)" was published in February 2019. This guideline was developed in the context of the guidelines program of the German Society of Gynecology and Obstetrics (DGGG) in cooperation with the Swiss Society of Gynecology and Obstetrics (SGGG) and the Austrian Society of Gynecology and Obstetrics (OEGGG). Aims One third of the causes of involuntary childlessness are still unclear, even if the woman or man have numerous possible risk factors. Because the topic is still very much taboo, couples may be socially isolated and often only present quite late to a fertility center. At present, there is no standard treatment concept, as currently no standard multidisciplinary procedures exist for the diagnostic workup and treatment of infertility. The aim of this guideline is to provide physicians with evidence-based recommendations for counselling, diagnostic workup and treatment. Methods This S2k guideline was developed on behalf of the Guidelines Commission of the DGGG by representative members from different professional medical organizations and societies using a structured consensus process. Recommendations The first part of this guideline focuses on the basic assessment of affected women, including standard anatomical and endocrinological diagnostic procedures and examinations into any potential infections. Other areas addressed in this guideline are the immunological workup with an evaluation of the patient's vaccination status, an evaluation of psychological factors, and the collection of data relating to other relevant factors affecting infertility. The second part will focus on explanations of diagnostic procedures compiled in collaboration with specialists from other medical specialties such as andrologists, human geneticists and oncologists.

Diagnosis and Treatment Before Assisted Reproductive Treatments. Guideline of the DGGG, OEGGG and SGGG (S2k Level, AWMF Register Number 015-085, February 2019) - Part 2, Hemostaseology, Andrology, Genetics and History of Malignant Disease

Introduction Supporting and counselling couples with fertility issues prior to starting ART is a multidisciplinary diagnostic and therapeutic challenge. The first German-language interdisciplinary S2k guideline on "Diagnosis and Therapy Before Assisted Reproductive Treatments (ART)" was published in February 2019. The guideline was developed in the context of the guidelines program of the German Society of Gynecology and Obstetrics (DGGG) in cooperation with the Swiss Society of Gynecology and Obstetrics (SGGG) and the Austrian Society of Gynecology and Obstetrics (OEGGG). Aim In one third of cases, the cause of involuntary childlessness remains unclear, even if the woman or man have numerous possible risk factors. Because the topic is still very much taboo, couples may be socially isolated and often only present quite late to a fertility center. There is no standard treatment concept for these patients at present, as there are currently no standard multidisciplinary procedures for the diagnostic workup and treatment of infertility. The aim of this guideline is to provide physicians with evidence-based recommendations for counselling, diagnosis and treatment. Methods This S2k guideline was developed on behalf of the Guidelines Commission of the DGGG by representative members from different professional medical organizations and societies using a structured consensus process. Recommendations This second part of the guideline describes the hematological workup for women as well as additional diagnostic procedures which can be used to investigate couples and which are carried out in cooperation with physicians working in other medical fields such as andrologists, geneticists and oncologists.

Anti α-enolase antibody is a novel autoimmune biomarker for unexplained recurrent miscarriages

Background

We recently demonstrated the increased abundance of anti-trophoblast antibodies (ATAB) in sera of patients with unexplained recurrent miscarriages (uRM). Further, the ATAB-positive sera bound to JEG-3 human choriocarcinoma cells in vitro, resulting in decreased productions of β-human chorionic gonadotropin (β-hCG) and progesterone in these cells. However, the specific antigenic epitopes of ATAB have remained unknown. Therefore, it was the aim of this study to determine specific targets of ATAB in uRM patients.

Methods

Potential targets of ATAB were analyzed by 2-dimensional difference gel electrophoresis (2D-DIGE) and mass spectrometry, and thereby identifying α-Enolase (ENO1). ATAB targeting of ENO1 was further confirmed in a competitive binding assay. Levels of anti-ENO1 antibodies as well as β-hCG and progesterone were quantified with enzyme-linked immunosorbent assay (ELISA). Additionally, expression of ENO1 was analyzed in first trimester placentas by immunohistochemistry and immunofluorescence analysis.

Findings

We here identified ENO1 as a prominent target of ATAB. Serum levels of anti-ENO1 antibodies were increased in ATAB-positive compared to ATAB-negative patients. Further, increased expression of ENO1 and its co-expression with β-arrestin was found in the extra villous trophoblasts of uRM patients in first trimester placentas. In vitro, anti-ENO1 antibodies decreased the secretion of β-hCG and progesterone in JEG-3 and primary human villous trophoblast cells.

Interpretation

Serum anti-ENO1 antibodies might be an autoimmune biomarker for uRM. Targeting the formation of anti-ENO1 antibodies or inhibition of ENO1 expression could potentially represent therapeutic strategies for these patients.

Fund

All authors declare no conflict of interest. Yao Ye was supported by the China Scholarship Council. Hellen Ishikawa-Ankerhold and Christian Schulz were supported by the SFB914, projects Z01 and A10. None of the rest authors has any conflict of interest to declare.

Unexplained recurrent miscarriages are associated with an aberrant sperm protamine mRNA content

STUDY QUESTION

Are unexplained recurrent miscarriages associated with abnormal protamine-1 and protamine-2 mRNA levels in spermatozoa?

SUMMARY ANSWER

Both protamine-1 and protamine-2 mRNA levels as well as the protamine-1 to protamine-2 mRNA ratio in spermatozoa from men whose female partners experienced two or more consecutive miscarriages were significantly different compared to those from both healthy control men and subfertile couples undergoing IVF/ICSI.

WHAT IS KNOWN ALREADY

Aberrant sperm protamine ratios are known to be associated with male-factor infertility. Data from this study suggest that the protamine mRNA ratio may additionally affect early embryo development.

STUDY DESIGN, SIZE, DURATION

The study population was recruited from men whose female partners presented with two or more consecutive unexplained miscarriages in a consultation for recurrent pregnancy loss between 2014 and 2016. At the research laboratory of the Urological Clinic of the University Giessen, spermatozoa from cases and controls were subjected to reverse transcription quantitative PCR (RTqPCR) using specific primer pairs for protamine-1 and protamine-2.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Protamine-1 and protamine-2 mRNA levels were analysed in semen samples from 25 men whose female partners experienced at least two consecutive idiopathic miscarriages before the 20th week of gestation. The couples were recruited during consultation at the Fertility Center of the LMU Munich, Germany, and at the Clinical Division of Gynecologic Endocrinology and Reproductive Medicine of the Medical University of Vienna, Austria. Results were compared with those from 32 healthy donors (WHO, 2010) recruited at the Department of Urology, Pediatric Urology and Andrology, Giessen, Germany, and 107 men whose partners participated in an IVF/ICSI program at the Fertility Center of the LMU Munich, Germany.

MAIN RESULTS AND THE ROLE OF CHANCE

Protamine-1 and protamine-2 mRNA levels as well as the protamine mRNA ratio and all routine semen parameters revealed significant differences between recurrent miscarriage couples and healthy volunteers (P < 0.01). When comparing recurrent miscarriage couples with couples undergoing IVF/ICSI, Ct-values of protamine-1 and protamine-2 mRNAs were significantly higher and the protamine mRNA ratio was significantly lower in RM couples (P < 0.01). When comparing protamine mRNA levels and the protamine mRNA ratio with routine semen parameters, a significant negative correlation was evident between progressive motility and the protamine-2 mRNA level (P = 0.015), as well as between non-progressive motility and the protamine mRNA ratio (P = 0.023).

LIMITATIONS REASONS FOR CAUTION

Although our data demonstrate significant abnormalities in RM, larger sample sizes will be needed to confirm our results. Larger sample sizes should also balance the fact that we had to focus mainly on median protamine mRNA levels. Finally, men in the healthy control group were younger in age than those in the case group, which might have introduced some bias, at least concerning the classic semen parameters. Moreover, only protamine mRNA instead of protein levels could be measured.

WIDER IMPLICATIONS OF THE FINDINGS

Although the exact mechanism remains to be elucidated, our data suggest that protamine mRNA levels in spermatozoa are not only important for successful fertilization, but also for proper development of the early embryo.

STUDY FUNDING/COMPETING INTEREST(S)

Grant from the University Clinic Giessen and Marburg (UKGM 29/2015GI). There are no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Recurrent Miscarriage: Diagnostic and Therapeutic Procedures. Guideline of the DGGG, OEGGG and SGGG (S2k-Level, AWMF Registry Number 015/050)

Purpose

Official guideline of the German Society of Gynecology and Obstetrics (DGGG), the Austrian Society of Gynecology and Obstetrics (ÖGGG) and the Swiss Society of Gynecology and Obstetrics (SGGG). The aim of this guideline was to standardize the diagnosis and treatment of couples with recurrent miscarriage (RM). Recommendations were based on the current literature and the views of the involved committee members.

Methods

Based on the current literature, the committee members developed the statements and recommendations of this guideline in a formalized process which included DELPHI rounds and a formal consensus meeting.

Recommendations

Recommendations for the diagnosis and treatment of patients with RM were compiled based on the international literature. Specific established risk factors such as chromosomal, anatomical, endocrine, hemostatic, psychological, infectious and immunological disorders were taken into consideration.

Lessons From the EThIGII Trial

This study presents sample size considerations derived from the Efficacy of Thromboprophylaxis as an Intervention during Gravidity (EThIGII) trial (ClinicalTrials.gov: NCT00400387) to address the question of low-molecular-weight heparin (LMWH) treatment in women with recurrent pregnancy loss (RPL) depending on the M2/ANXA5 haplotype. To evaluate the possible influence of such treatment on miscarriage rates of trial participants, a post hoc analysis of ANXA5 promoter genotypes in the light of M2/ANXA5 ( RPRGL3) distribution was performed using logistic models. DNA for genotyping was available from 129 LMWH and 95 control patients, 44 (19.6%) of whom were M2/ANXA5 carriers. Miscarriages occurred in 1 (4.0%) of 25 M2/ANXA5 carriers from the LMWH group compared to 4 (21.1%) of 19 in the control group, resulting in an odds ratio (95% confidence interval) for miscarriage of 0.16 (0.016-1.5) for women treated with LMWH. In noncarriers, miscarriage rates were 6 (5.8%) of 104 versus 7 (9.2%) of 76 for the LMWH and the control groups, respectively, corresponding to an odds ratio for miscarriage of 0.60 (0.19-1.9). The apparent beneficial effects of miscarriage rate reduction in M2/ANXA5 carriers with RPL concur with biological considerations about improvement in reduced ANXA5 function through LMWH treatment in an adequate murine model. The data obtained were instrumental to design proper assessment of the existence and magnitude of this effect.

TET enzymes are successively expressed during human spermatogenesis and their expression level is pivotal for male fertility

STUDY QUESTION

Are ten-eleven-translocation (TET) 1-3 family enzymes involved in human spermatogenesis and do they impact male fertility?

SUMMARY ANSWER

TET1, TET2 and TET3 are successively expressed at different stages of human spermatogenesis, and their expression levels associate with male fertility.

WHAT IS KNOWN ALREADY

Spermatogenesis is a complex cell differentiation process accompanied by a drastic epigenetic remodeling. TET1-3 dioxygenases are essential for active DNA demethylation in the paternal pronucleus and in embryonic stem cells.

STUDY DESIGN, SIZE, DURATION

Expression of TET1-3 mRNAs and proteinss and 5-hydroxymethylcytosine (5-hmC) proteins were analyzed in human testis tissues from men with obstructive azoospermia and exhibiting histologically normal spermatogenesis. Ejaculated spermatozoa from normozoospermic healthy volunteers, the 'controls' (TET1: n = 58; TET2-3: n = 63), and subfertile men who participated with their female partners in an ICSI-program, the 'patients' (TET1: n = 66; TET2-3: n = 64), were analyzed concerning the stored TET1-3 mRNAs, and the values were correlated to semen parameters and ICSI-outcomes.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Testis sections were used for in situ hybridization (ISH) and immunohistochemical (IHC) studies to determine TET1-3 mRNA and protein expression, and for immunofluorescence (IF) detection of 5-hmC. Sperm samples from controls were analyzed by western blot, immunocytochemistry (ICC) and RT-PCR concerning the presence of non-degraded TET1-3 protein and mRNA. Sperm samples from controls and patients were used for quantitative TET1-3 mRNA analyses (reverse transcription-polymerase chain reaction) and for comparative statistical evaluations under consideration of semen parameters and ICSI-outcome (pregnancy).

MAIN RESULTS AND THE ROLE OF CHANCE

During human spermatogenesis TET1-3 proteins are successively expressed: TET2 is expressed in the cytoplasm of late pachytene spermatocytes of Stage V, TET1 starts to be expressed in the nuclei of Step 1 round spermatids at Stage I, and TET3 starts to be expressed in the nuclei of Step 3 round spermatids at Stage III. Five-hmC appears only in Step 5 elongated spermatids. All three TETs are still detectable at the mRNA and protein level in sperm cells in considerable amounts. Control men generally exhibited higher levels of TET1-3 in sperm. TET1- and TET3-mRNA levels in sperm were significantly negatively correlated with age (P = 0.0025 and P = 0.0343) and positively correlated with progressive sperm motility (P = 0.0007 and P = 0.018). All TETs showed a significant association with sperm concentration (P < 0.03). Patients diagnosed with oligozoospermia and/or asthenozoospermia (TET1: n = 35; TET2-3: n = 32) showed significantly reduced TET1-3 in sperm in comparison to controls (P = 0.003, P = 0.041 and P = 0.028), but not compared with normozoospermic patients. Levels of TET3 in sperm was significantly associated with high-fertilization rates (P = 0.009). Concerning ICSI-outcome, the lowest levels of TET1-3 mRNAs in sperm were found in the non-pregnant group. Increased TET2 in sperm was significantly associated with pregnancy (P = 0.006).

LIMITATIONS, REASONS FOR CAUTION

Our results concerning the association of the mRNA level of TETs in ejaculated sperm cells to different fertility parameters are descriptive. Further studies clarifying the reasons for decreased TET1-3 levels in subfertile men and their effect on their sperm methylome are essential.

WIDER IMPLICATIONS OF THE FINDINGS

The study gives a substantial indication that in human spermiogenesis, an active DNA demethylation process occurs with an involvement of TET enzymes, and that the level of TET1-3 expression is pivotal for male fertility.

STUDY FUNDING

Research grant from the German Research Foundation (DFG) to U.S. (SCHA1531/1-1 and SCHA1531/2-1).

COMPETING INTERESTS

None.