Antioxidants for female subfertility

Effect of omega-3 supplements or diets on fertility in women: A meta-analysis

Objective

This study aimed to assess the effect of increased omega-3 consumption on fertilization rates and the probability of women getting pregnant. This study is needed because different perspectives exist regarding the use of omega-3 fatty acids in enhancing fertility among women with reproductive issues, and information for those planning a spontaneous pregnancy is limited.

Methods

PubMed, Clinical Trials, CINAHL/EBSCO, Medline Complete, Cochrane Library, and Google Scholar were searched for articles published until April 2021, and the search was limited to articles in English language. The search strategy included the following key words: "in-vitro fertilization (IVF)," "intracytoplasmic sperm injection techniques (ICSI)," "pregnancy," "omega-3 fatty acid," "alpha-linolenic acid," "eicosapentaenoic acid," "docosahexaenoic acid," "n-3 polyunsaturated fatty acid," and "fish oil and seafood." Studies reporting female fertility occurring naturally or IVF/ICSI concurrent with omega-3 intake were included. Retrospective studies, studies including postmenopausal women, and unevenly matched control and study groups were excluded. To assess bias, we used the Cochrane Handbook for Systematic Reviews of Interventions, version 5.1.0. To synthesize the findings from the studies included in this review, a meta-analysis was conducted using calculated or extracted odds ratios (OR) of clinical pregnancies and fertilization rates for each group in each study.

Results

We included six trials involving 1789 women who received fertility treatment, four trials involving 2607 women who conceived naturally, and three trials involving 1725 oocytes for fertility rates. Aggregated ORs for the effects of omega-3 on pregnancies were 1.74, 1.36, and 2.14 for women who received fertility treatment, those who conceived naturally, and fertilization rate, respectively. All these results were significant (p ≤ 0.01), although they had high heterogeneity I2>68 %.

Conclusion

This systematic review and meta-analysis suggest that omega-3 intake significantly improves women's pregnancy and fertilization rates; however, the high heterogeneity in this review somewhat limits its interpretation. Therefore, further prospective randomized studies are necessary to better understand this relationship.

Targeting Oxidative Stress Involved in Endometriosis and Its Pain

Endometriosis is a common gynecological disorder seen in women and is characterized by chronic pelvic pain and infertility. This disorder is becoming more prevalent with increased morbidity. The etiology of endometriosis remains to be fully elucidated, which will lead to improved therapeutic options. In this review, we will evaluate the biochemical mechanisms leading to oxidative stress and their implication in the pathophysiology of endometriosis, as well as potential treatments that target these processes. A comprehensive exploration of previous research revealed that endometriosis is associated with elevated reactive oxygen species and oxidation products, decreased antioxidants and detoxification enzymes, and dysregulated iron metabolism. High levels of oxidative stress contributed to inflammation, extracellular matrix degradation, angiogenesis, and cell proliferation, which may explain its role in endometriosis. Endometriosis-associated pain was attributed to neurogenic inflammation and a feed-forward mechanism involving macrophages, pro-inflammatory cytokines, and pain-inducing prostaglandins. N-acetylcysteine, curcumin, melatonin, and combined vitamin C and E supplementation displayed promising results for the treatment of endometriosis, but further research is needed for their use in this population.

Association between serum 25-hydroxy vitamin D level and menstrual cycle length and regularity: A cross-sectional observational study

Background

Research examining the role of vitamin D deficiency and the development of menstrual disorders in women is of widespread interest. Studies have been published showing that supplementation with high-dose vitamin D can lead to the restoration of the menstrual cycle. We lack adequate information regarding the effect of vitamin D levels on the physiology of menstruation and further on fertility in women of reproductive age due to the contradictory results reported by studies.

Objective

To study the association of 25-hydroxy vitamin D with menstrual cycle characteristics including long and short cycle length and cycle irregularity.

Materials and Methods

In this cross-sectional study, serum vitamin D levels of 166 women attending an outpatient department with menstrual irregularities after excluding all obvious causes of menstrual disorders (n = 83) between April-June 2019 were measured and were compared with women of similar profiles with complaints other than menstrual irregularities (n = 83).

Results

A decreased level of vitamin D was associated with a 13.3 times odds of an irregular cycle (OR (95% CI): 13.30 (5.79-30.60), p < 0.001). 25-hydroxy vitamin D was not associated with age or body mass index. We found a significant difference (p < 0.001) in mean vitamin D levels among the females with irregular cycles vs. regular cycles.

Conclusion

Vitamin D plays a role in the physiology of reproduction specific to the menstrual cycle and ovulation. Long-term prospective studies assessing the exact cutoff value and the exact dose of supplementation required are needed.

Mitochondria: Their relevance during oocyte ageing

The oocyte is recognised as the largest cell in mammalian species and other multicellular organisms. Mitochondria represent a high proportion of the cytoplasm in oocytes and mitochondrial architecture is different in oocytes than in somatic cells, characterised by a rounder appearance and fragmented network. Although the number of mitochondria per oocyte is higher than in any other mammalian cell, their number and activity decrease with advancing age. Mitochondria integrate numerous processes essential for cellular function, such as metabolic processes related to energy production, biosynthesis, and waste removal, as well as Ca²⁺ signalling and reactive oxygen species (ROS) homeostasis. Further, mitochondria are responsible for the cellular adaptation to different types of stressors such as oxidative stress or DNA damage. When these stressors outstrip the adaptive capacity of mitochondria to restore homeostasis, it leads to mitochondrial dysfunction. Decades of studies indicate that mitochondrial function is multifaceted, which is reflected in the oocyte, where mitochondria support numerous processes during oocyte maturation, fertilization, and early embryonic development. Dysregulation of mitochondrial processes has been consistently reported in ageing and age-related diseases. In this review, we describe the functions of mitochondria as bioenergetic powerhouses and signal transducers in oocytes, how dysfunction of mitochondrial processes contributes to reproductive ageing, and whether mitochondria could be targeted to promote oocyte rejuvenation.

Dietary Energy Density and Fertility: Results from the Lifestyle and Fertility Study

BACKGROUND

Diet is a modifiable lifestyle factor linked with fertility in a growing number of studies.

OBJECTIVE

The objective of this study was to evaluate the association between dietary energy density (ED), a summary measure of diet quality that estimates the amount of energy per unit food (kcal/g) consumed, and conception and pregnancy outcomes.

METHODS

A prospective cohort study of couples planning their first pregnancy was conducted in the Northeast region of the USA. Dietary data were collected prior to conception via 3 unannounced interviewer-administered 24-h dietary recalls. Multivariable-adjusted logistic regression (ORs and Cox proportional hazards models [RR] and 95% CIs) were estimated for continuous and categorical (tertile [T]) variables of dietary ED.

RESULTS

The majority of women (n = 80; 61%) achieved clinical pregnancy. Median time to conception of a clincal pregnancy(TTC) for those who conceived was 4.64 mo with an IQR of 4.37 mo. ED modeled as a continuous variable was not associated with clinical pregnancy, live birth, or TTC after controlling for race, physical activity, and male partner's ED. When ED was categorized to consider nonlinear associations, 60%, 73%, and 50% of the participants in the tertiles (from lowest ED to highest) achieved clinical pregnancy. In multivariable logistic analyses with the middle group as the referent (ED = 1.37-1.60), membership in the highest ED group (ED >1.60) was associated with lower odds of clinical pregnancy (OR = 0.30; 95% CI: 0.11, 0.81, P = 0.02). In Cox proportional hazards analyses, membership in the highest ED group was associated with significantly longer TTC compared with the middle category (HR = 0.41; 95% CI: 0.21,0.82, P = 0.01).

CONCLUSIONS

These results suggest that high dietary ED is associated with reduced fertility.This study evaluated associations between dietary energy density and the probability of conceiving clinical pregnancy, having a live birth, and the time to conception among couples planning pregnancy.

Nutrition in Gynecological Diseases: Current Perspectives

Diet and nutrition are fundamental in maintaining the general health of populations, including women’s health. Health status can be affected by nutrient deficiency and vice versa. Gene–nutrient interactions are important contributors to health management and disease prevention. Nutrition can alter gene expression, as well as the susceptibility to diseases, including cancer, through several mechanisms. Gynecological diseases in general are diseases involving the female reproductive system and include benign and malignant tumors, infections, and endocrine diseases. Benign diseases such as uterine fibroids and endometriosis are common, with a negative impact on women’s quality of life, while malignant tumors are among the most common cause of death in the recent years. In this comprehensive review article, a bibliographic search was performed for retrieving information about nutrients and how their deficiencies can be associated with gynecological diseases, namely polycystic ovary syndrome, infertility, uterine fibroids, endometriosis, dysmenorrhea, and infections, as well as cervical, endometrial, and ovarian cancers. Moreover, we discussed the potential beneficial impact of promising natural compounds and dietary supplements on alleviating these significant diseases.

Transferrin and antioxidants partly prevented mouse oocyte oxidative damage induced by exposure of cumulus-oocyte complexes to endometrioma fluid

Background

Exposure of oocytes to the endometrioma fluid has an adverse effect on embryonic quality. To determine whether adding transferrin and antioxidants to culture medium could counteract detrimental effects on mouse cumulus-oocyte complexes (COCs) induced by exposure to endometrioma fluid or not, we conducted an in vitro cross-sectional study using human and mouse COCs.

Methods

Eighteen women who had their oocytes exposed to endometrioma fluid during oocyte retrieval were enrolled. COCs from superovulated ICR female mice were collected. They were first exposed to human endometrioma fluid and then treated by transferrin and/or antioxidants (cysteamine + cystine). Subsequently, COCs function was assessed by molecular methods.

Results

This study observed that human COCs inadvertently exposed to endometrioma fluid in the in vitro fertilization (IVF) group led to a lower good quality embryo rate compared to intracytoplasmic sperm injection (ICSI) group. Exposure of mouse COCs to endometrioma fluid accelerated oocyte oxidative damage, evidenced by significantly reduced CCs viability, defective mitochondrial function, decreased GSH content and increased ROS level, associated with the significantly higher pro-portion of abnormal spindles and lower blastocyst formation (p < 0.05, respectively). This damage could be recovered partly by treating COCs with transferrin and antioxidants (cysteamine + cystine).

Conclusions

Transferrin and antioxidants could reduce the oxidative damage caused by COCs exposure to endometrioma fluid. This finding provides a promising new possibility for intervention in the human oocyte oxidative damage process induced by endometrioma fluid during oocyte pick-up.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13048-020-00738-0.

Mitochondria-targeted therapy rescues development and quality of embryos derived from oocytes matured under oxidative stress conditions: a bovine in vitro model

STUDY QUESTION

Can we use a mitochondrial-targeted antioxidant (Mitoquinone) during in vitro embryo culture to rescue developmental competence of oocytes matured under lipotoxic conditions, exhibiting mitochondrial dysfunction and oxidative stress?

SUMMARY ANSWER

Supplementation of embryo culture media with Mitoquinone reduced oxidative stress and prevented mitochondrial uncoupling in embryos derived from metabolically compromised oocytes in vitro, leading to higher blastocyst rates and lower blastomeric apoptosis.

WHAT IS KNOWN ALREADY

Maternal metabolic disorders, such as obesity and type-II diabetes are associated with hyperlipidemia and elevated free fatty acid (FFA) concentrations in the ovarian follicular fluid (FF). Oocyte maturation under these lipotoxic conditions results in increased oxidative stress levels, mitochondrial dysfunction, reduced developmental competence and disappointing IVF results.

STUDY DESIGN, SIZE, DURATION

A well-described bovine oocyte IVM model was used, where a pathophysiologically relevant elevated FF concentrations of palmitic acid (PA; 150 μM or 300 μM) were added to induce oxidative stress. After fertilization (Day 0, D0), zygotes were in vitro cultured (IVC, from D1 to D8) in standard fatty acid-free media in the presence or absence of Mitoquinone or its carrier triphenyl-phosphonium.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Embryo cleavage and fragmentation (D2) and blastocyst rates (D8) were recorded. Mitochondrial activity and oxidative stress in cleaved embryos at D2 were determined using specific fluorogenic probes and confocal microscopy. D8 blastocysts were used to (i) examine the expression of marker genes related to mitochondrial unfolded protein responses (UPRmt; HSPD1 and HSPE1), mitochondrial biogenesis (TFAM), endoplasmic reticulum (ER) UPR (ATF4, ATF6 and BiP) and oxidative stress (CAT, GPX1 and SOD2) using real time RT-PCR; (ii) determine cell differentiation and apoptosis using CDX-2 and cleaved caspase-3 immunostaining; and (iii) measure mtDNA copy numbers. This was tested in a series of experiments with at least three independent replicates for each, using a total of 2525 oocytes. Differences were considered significant if a P value was <0.05 after Bonferroni correction.

MAIN RESULTS AND THE ROLE OF CHANCE

Exposure to PA during IVM followed by culture under control conditions resulted in a significant increase in oxidative stress in embryos at D2. This was associated with a significant reduction in mitochondrial inner membrane potential (uncoupling) compared with solvent control (P < 0.05). The magnitude of these effects was PA-concentration dependent. Consequently, development to the blastocysts stage was significantly hampered. Surviving blastocysts exhibited high apoptotic cell indices and upregulated mRNA expression indicating persistent oxidative stress, mitochondrial and ER UPRs. In contrast, supplementation of PA-derived zygotes with Mitoquinone during IVC (i) prevented mitochondrial uncoupling and alleviated oxidative stress at D2; and (ii) rescued blastocyst quality; normalized oxidative stress and UPR related genes and apoptotic cell indices (P > 0.01 compared with solvent control). Mitoquinone also improved blastocyst rate in PA-exposed groups, an effect that was dependent on PA concentration.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

This is a fundamental study performed using a bovine in vitro model using PA-induced lipotoxicity during oocyte maturation. PA is the most predominant FFA in the FF that is known to induce lipotoxicity; however, in vivo maturation in patients suffering from maternal metabolic disorders involve more factors that cannot be represented in one model. Nevertheless, focusing on the carryover oxidative stress as a known key factor affecting developmental competence, and considering the novel beneficial rescuing effects of Mitoquinone shown here, we believe this model is of high biological relevance.

WIDER IMPLICATIONS OF THE FINDINGS

Human oocytes collected for IVF treatments from patients with maternal metabolic disorders are vulnerable to lipotoxicity and oxidative stress during in vivo maturation. The results shown here suggest that mitochondrial targeted therapy, such as using Mitoquinone, during IVC may rescue the developmental competence and quality of these compromised oocytes. After further clinical trials, this may be a valuable approach to increase IVF success rates for infertile patients experiencing metabolic disorders.

STUDY FUNDING/COMPETING INTEREST(S)

This study was financially supported by a BOF/KP grant number 34399, from the University of Antwerp, Belgium. W.F.A.M. was supported by a postdoctoral fellowship from the Research Foundation-Flanders (FWO), grant number 12I1417N, Antwerp, Belgium. The Leica SP 8 confocal microscope used in this study was funded by the Hercules Foundation of the Flemish Government (Hercules grant AUHA.15.12). All authors have no financial or non-financial competing interests to declare.

Antioxidants for female subfertility

BACKGROUND

A couple may be considered to have fertility problems if they have been trying to conceive for over a year with no success. This may affect up to a quarter of all couples planning a child. It is estimated that for 40% to 50% of couples, subfertility may result from factors affecting women. Antioxidants are thought to reduce the oxidative stress brought on by these conditions. Currently, limited evidence suggests that antioxidants improve fertility, and trials have explored this area with varied results. This review assesses the evidence for the effectiveness of different antioxidants in female subfertility.

OBJECTIVES

To determine whether supplementary oral antioxidants compared with placebo, no treatment/standard treatment or another antioxidant improve fertility outcomes for subfertile women.

SEARCH METHODS

We searched the following databases (from their inception to September 2019), with no language or date restriction: Cochrane Gynaecology and Fertility Group (CGFG) specialised register, CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL and AMED. We checked reference lists of relevant studies and searched the trial registers.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared any type, dose or combination of oral antioxidant supplement with placebo, no treatment or treatment with another antioxidant, among women attending a reproductive clinic. We excluded trials comparing antioxidants with fertility drugs alone and trials that only included fertile women attending a fertility clinic because of male partner infertility.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. The primary review outcome was live birth; secondary outcomes included clinical pregnancy rates and adverse events.

MAIN RESULTS

We included 63 trials involving 7760 women. Investigators compared oral antioxidants, including: combinations of antioxidants, N-acetylcysteine, melatonin, L-arginine, myo-inositol, carnitine, selenium, vitamin E, vitamin B complex, vitamin C, vitamin D+calcium, CoQ10, and omega-3-polyunsaturated fatty acids versus placebo, no treatment/standard treatment or another antioxidant. Only 27 of the 63 included trials reported funding sources. Due to the very low-quality of the evidence we are uncertain whether antioxidants improve live birth rate compared with placebo or no treatment/standard treatment (odds ratio (OR) 1.81, 95% confidence interval (CI) 1.36 to 2.43; P < 0.001, I² = 29%; 13 RCTs, 1227 women). This suggests that among subfertile women with an expected live birth rate of 19%, the rate among women using antioxidants would be between 24% and 36%. Low-quality evidence suggests that antioxidants may improve clinical pregnancy rate compared with placebo or no treatment/standard treatment (OR 1.65, 95% CI 1.43 to 1.89; P < 0.001, I² = 63%; 35 RCTs, 5165 women). This suggests that among subfertile women with an expected clinical pregnancy rate of 19%, the rate among women using antioxidants would be between 25% and 30%. Heterogeneity was moderately high. Overall 28 trials reported on various adverse events in the meta-analysis. The evidence suggests that the use of antioxidants makes no difference between the groups in rates of miscarriage (OR 1.13, 95% CI 0.82 to 1.55; P = 0.46, I² = 0%; 24 RCTs, 3229 women; low-quality evidence). There was also no evidence of a difference between the groups in rates of multiple pregnancy (OR 1.00, 95% CI 0.63 to 1.56; P = 0.99, I² = 0%; 9 RCTs, 1886 women; low-quality evidence). There was also no evidence of a difference between the groups in rates of gastrointestinal disturbances (OR 1.55, 95% CI 0.47 to 5.10; P = 0.47, I² = 0%; 3 RCTs, 343 women; low-quality evidence). Low-quality evidence showed that there was also no difference between the groups in rates of ectopic pregnancy (OR 1.40, 95% CI 0.27 to 7.20; P = 0.69, I² = 0%; 4 RCTs, 404 women). In the antioxidant versus antioxidant comparison, low-quality evidence shows no difference in a lower dose of melatonin being associated with an increased live-birth rate compared with higher-dose melatonin (OR 0.94, 95% CI 0.41 to 2.15; P = 0.89, I² = 0%; 2 RCTs, 140 women). This suggests that among subfertile women with an expected live-birth rate of 24%, the rate among women using a lower dose of melatonin compared to a higher dose would be between 12% and 40%. Similarly with clinical pregnancy, there was no evidence of a difference between the groups in rates between a lower and a higher dose of melatonin (OR 0.94, 95% CI 0.41 to 2.15; P = 0.89, I² = 0%; 2 RCTs, 140 women). Three trials reported on miscarriage in the antioxidant versus antioxidant comparison (two used doses of melatonin and one compared N-acetylcysteine versus L-carnitine). There were no miscarriages in either melatonin trial. Multiple pregnancy and gastrointestinal disturbances were not reported, and ectopic pregnancy was reported by only one trial, with no events. The study comparing N-acetylcysteine with L-carnitine did not report live birth rate. Very low-quality evidence shows no evidence of a difference in clinical pregnancy (OR 0.81, 95% CI 0.33 to 2.00; 1 RCT, 164 women; low-quality evidence). Low quality evidence shows no difference in miscarriage (OR 1.54, 95% CI 0.42 to 5.67; 1 RCT, 164 women; low-quality evidence). The study did not report multiple pregnancy, gastrointestinal disturbances or ectopic pregnancy. The overall quality of evidence was limited by serious risk of bias associated with poor reporting of methods, imprecision and inconsistency.

AUTHORS' CONCLUSIONS

In this review, there was low- to very low-quality evidence to show that taking an antioxidant may benefit subfertile women. Overall, there is no evidence of increased risk of miscarriage, multiple births, gastrointestinal effects or ectopic pregnancies, but evidence was of very low quality. At this time, there is limited evidence in support of supplemental oral antioxidants for subfertile women.

Adjuvants in IVF-evidence for what works and what does not work

The field of assisted reproductive technology is shaped and changed constantly by advances in science and cutting-edge innovations. In a quest to maximise outcomes, add-on interventions are often adopted and utilised prematurely while the principles of evidence-based medicine seem to be less strictly adhered to. In this review we will attempt to summarise the latest evidence about some of the adjuvants.

Redox Biology of Human Cumulus Cells: Basic Concepts, Impact on Oocyte Quality, and Potential Clinical Use

Significance: Four decades have passed since the first successful human embryo conceived from a fertilization in vitro. Despite all advances, success rates in assisted reproduction techniques still remain unsatisfactory and it is well established that oxidative stress can be one of the major factors causing failure in in vitro fertilization (IVF) techniques. Recent Advances: In the past years, researchers have been shown details of the supportive role CCs play along oocyte maturation, development, and fertilization processes. Regarding redox metabolism, it is now evident that the synergism between gamete and somatic CCs is fundamental to further support a healthy embryo, since the oocyte lacks several defense mechanisms that are provided by the CCs. Critical Issues: There are many sources of reactive oxygen species (ROS) in the female reproductive tract in vivo that can be exacerbated (or aggravated) by pathological features. While an imbalance between ROS and antioxidants can result in oxidative damage, physiological levels of ROS are essential for oocyte maturation, ovulation, and early embryonic growth where they act as signaling molecules. At the event of an assisted reproduction procedure, the cumulus/oophorus complex is exposed to additional sources of oxidative stress in vitro. The cumulus cells (CCs) play essential roles in protecting the oocytes from oxidative damage. Future Directions: More studies are needed to elucidate redox biology in human CCs and oocyte. Also, randomized controlled trials will identify possible benefits of in vivo or in vitro administration of antioxidants for patients seeking IVF procedure.

Antioxidant effect of genistein on ovarian tissue morphology, oxidant and antioxidant activity in rats with induced polycystic ovary syndrome

Background

Oxidative stress is the most frequent cause of female infertility disorders including polycystic ovary syndrome (PCOS). Genistein as a major component of soybean isoflavone scavenges free radicals by antioxidant activities.

Objective

The present study examines the antioxidant effects of genistein on ovarian tissue following experimental PCOS in rats.

Materials and Methods

Twenty female Wistar rat were randomly divided into the following groups (n=5 each group): (I) control group (no treatment); (II) induced PCOS (injection of estradiol valerate); (III) genistein-treated non-PCOS (received genistein); and (IV) genistein-treated PCOS groups. The weight of rats were measured and the blood samples collected and centrifuged. The oxidant and antioxidant activity of plasma and ovaries were measured. All rats were sacrificed under anesthesia, and ovaries were collected and weighted. Histological examination and follicular quality were assessed by staining.

Results

In histological observation, the induced PCOS rats displayed more number of atretic follicles and the follicular quality in genistein-treated rats was similar to the control groups. The plasma and ovaries malondialdehyde levels significantly increased in PCOS rats (p < 0.001), while the total antioxidant capacity levels, glutathione peroxidase, and superoxide dismutase activities significantly decreased (p < 0.001). The plasma and ovary malondialdehyde levels significantly decreased in PCOS rats that were treated with genistein (p < 0.001) and the total antioxidant capacity (p < 0.05), glutathione peroxidase, and superoxide dismutase activities significantly increased (p < 0.001).

Conclusion

Treatment with genistein preserved follicular quality by increasing antioxidant activities and scavenging oxidant levels in PCOS rats.

Nutrition and Female Fertility: An Interdependent Correlation

Besides aging, a number of non-modifiable lifestyle-related factors, such as smoking, elevated consumption of caffeine and alcohol, stress, agonist sports, chronic exposure to environmental pollutants, and other nutritional habits exert a negative impact on a women's fertility. In particular, metabolic disorders including diabetes, obesity, and hyperlipidemia commonly associated to hypercaloric diets are suspected to affect a woman's fertility either by direct damage to oocyte health and differentiation, or by indirect interference with the pituitary-hypothalamic axis, resulting in dysfunctional oogenesis. Obese women show decreased insulin sensitivity determining persistent hyperinsulinemia, which may be involved in the pathogenesis of Polycystic Ovary Syndrome. Thus, the reduced insulin secretion induced by dietary adjustments is an attractive non-pharmacological treatment to prevent infertility, and a Mediterranean diet aimed at maintaining normal body mass may be effective in the preservation of ovarian health and physiology. Furthermore, in relation to the oxidative stress as a co-factor of defective oocyte maturation, an appropriate intake of proteins, antioxidants and methyl-donor supplements (1-Carbon Cycle) may decrease the bioavailability of toxic oxidants resulting in the protection of oocyte maturation.

Declining Fertility with Reproductive Aging: How to Protect Your Patient's Fertility by Knowing the Milestones

Protection of fertility shares many of the same concepts as optimization of general health, such as smoking cessation, maintenance of a healthy body weight, and moderation of alcohol intake. Increasing attention has been placed on minimizing exposures to known reproductive toxicants. There are few conclusive data to support specific diet patterns or supplements for fertility. Ovarian reserve testing has been explored as potential diagnostic tests for assessment of reproductive aging with some controversy. Finally, the development of vitrification in the assisted reproduction laboratory has increased the success and, therefore, access to fertility preservation by way of oocyte or embryo cryopreservation.

Assisted reproductive technology: an overview of Cochrane Reviews

BACKGROUND

As many as one in six couples will encounter problems with fertility, defined as failure to achieve a clinical pregnancy after regular intercourse for 12 months. Increasingly, couples are turning to assisted reproductive technology (ART) for help with conceiving and ultimately giving birth to a healthy live baby of their own. Fertility treatments are complex, and each ART cycle consists of several steps. If one of these steps is incorrectly applied, the stakes are high as conception may not occur. With this in mind, it is important that each step of the ART cycle is supported by good evidence from well-designed studies.

OBJECTIVES

To summarise the evidence from Cochrane systematic reviews on procedures and treatment options available to couples with subfertility undergoing assisted reproductive technology (ART) procedures.

METHODS

Published Cochrane systematic reviews of couples undergoing ART procedures (in vitro fertilisation or intracytoplasmic sperm injection) were eligible for inclusion in the overview. We also identified Cochrane reviews in preparation, for future inclusion.The primary outcome of the overview was live birth or the composite outcome live birth or ongoing pregnancy, as reported by the included reviews. Our secondary outcomes were clinical pregnancy, multiple pregnancy, miscarriage, and ovarian hyperstimulation syndrome. We excluded studies of intrauterine insemination and ovulation induction.We undertook selection of systematic reviews, data extraction, and quality assessment in duplicate. We assessed review quality by using the AMSTAR tool. We organised reviews by their relevance to specific stages in the ART cycle. We summarised their findings in the text and reported data for each outcome in 'Additional tables'.

MAIN RESULTS

We included 68 systematic reviews published in the Cochrane Library up to May 2018. All were of high quality. These reviews identified 38 interventions that were effective (n = 23) or promising (n = 15), and they identified 19 interventions that were ineffective (n = 2) or possibly ineffective (n = 17). For 15 interventions, review authors were unable to draw conclusions owing to lack of evidence.We identified an additional 11 protocols and four titles for future inclusion in this overview.

AUTHORS' CONCLUSIONS

This overview provides the most up-to-date evidence on ART cycles from systematic reviews of randomised controlled trials. Fertility treatments are costly, and the stakes are high. Using the best available evidence to optimise outcomes is best practice. Evidence from this overview could be used to develop clinical practice guidelines and protocols that can be applied in daily clinical practice to improve live birth rates and reduce rates of multiple pregnancy, cycle cancellation, and ovarian hyperstimulation syndrome.

Strategies to decrease oxidative stress biomarker levels in human medical conditions: A meta-analysis on 8-iso-prostaglandin F2α

The widespread detection of elevated oxidative stress levels in many medical conditions has led to numerous efforts to design interventions to reduce its effects. Efforts have been wide-ranging, from dietary changes to administration of antioxidants, supplements, e.g., omega-3-fatty acids, and many medications. However, there is still no systemic assessment of the efficacy of treatments for oxidative stress reduction across a variety of medical conditions. The goal of this meta-analysis is, by combining multiple studies, to quantitate the change in the levels of the popular oxidative stress biomarker 8-iso-prostaglandin F2α (8-iso-PGF2α) after a variety of treatment strategies in human populations. Nearly 350 unique publications with 180 distinct strategies were included in the analysis. For each strategy, the difference between pre- or placebo and post-treatment levels calculated using Hedges' g value of effect. In general, administration of antibiotics, antihyperlipidemic agents, or changes in lifestyle (g = - 0.63, - 0.54, and 0.56) had the largest effect. Administration of supplements, antioxidants, or changes in diet (g = - 0.09, - 0.28, - 0.12) had small quantitative effects. To fully interpret the effectiveness of these treatments, comparisons to the increase in g value for each medical condition is required. For example, antioxidants in populations with coronary artery disease (CAD) reduce the 8-iso-PGF2α levels by g = - 0.34 ± 0.1, which is quantitatively considered a small effect. However, CAD populations, in comparison to healthy populations, have an increase in 8-iso-PGF2α levels by g = 0.38 ± 0.04; therefore, the overall reduction of 8-iso-PGF2α levels is ≈ 90% by this treatment in this specific medical condition. In conclusion, 8-iso-PGF2α levels can be reduced not only by antioxidants but by many other strategies. Not all strategies are equally effective at reducing 8-iso-PGF2α levels. In addition, the effectiveness of any strategy can be assessed only in relation to the medical condition investigated.

Diet and fertility: a review

The literature on the relationship between diet and human fertility has greatly expanded over the last decade, resulting in the identification of a few clear patterns. Intake of supplemental folic acid, particularly at doses higher than those recommended for the prevention of neural tube defects, has been consistently related to lower frequency of infertility, lower risk of pregnancy loss, and greater success in infertility treatment. On the other hand and despite promising evidence from animal models, vitamin D does not appear to exert an important role in human fertility in the absence of deficiency. Antioxidant supplementation does not appear to offer any benefits to women undergoing infertility treatment, but it appears to be beneficial when it is the male partner who is supplemented. However, the available evidence does not allow discerning which specific antioxidants, or at which doses, are responsible for this benefit. Long-chain omega-3 fatty acids appear to improve female fertility, although it remains unclear to what extent contamination of shared food sources, such as fish with high levels of environmental toxicants, can dampen this benefit. Lastly, adherence to healthy diets favoring seafood, poultry, whole grains, fruits, and vegetables are related to better fertility in women and better semen quality in men. The cumulative evidence has also piled against popular hypotheses. Dairy and soy, once proposed as reproductive toxicants, have not been consistently related to poor fertility. In fact, soy and soy supplements appear to exert a beneficial effect among women undergoing infertility treatment. Similarly, because data from large, high-quality studies continue to accumulate, the evidence of a potentially deleterious effect of moderate alcohol and caffeine intake on the ability to become pregnant seems less solid than it once did. While a complete picture of the role of nutrition on fertility is far from complete, much progress has been made. The most salient gaps in the current evidence include jointly considering female and male diets and testing the most consistent findings in randomized trials.

Anti-oxidant mediated normalisation of raised intracellular cytokines in patients with reproductive failure

Background

Raised intracellular cytokine ratios (CKR) are proposed as a significant risk factor for adverse reproductive outcome. An elevated cytokine ratio, such as between TNFa and/or IFNg to IL-10 is associated with recurrent miscarriage (RM). The use of pharmacological immunomodulators such as TNFα inhibitors in these patients is controversial and not generally recommended due to a lack of conclusive data supporting their use. We evaluated whether the use of anti-oxidants/dietary supplements as an alternative could positively influence CKR’s in ART patients.

Methods

A prospective non-placebo control trial of antioxidant treatment for abnormal peripheral inflammatory cytokine ratios was performed. CKRs were assessed using flow cytometry in stimulated versus unstimulated whole blood samples in 337 IVF patients presenting with a previous history of poor outcome (RM or implantation failure). CKR’s were found to be elevated in 150/337. 70/150 patients in this elevated group agreed to a 10 week regime of Omega 3, vitamin D3, and B complex, followed by retesting to evaluate effect.

Results

Mean cytokine ratios significantly improved between tests. Pre-treatment TNFa:IL-10 ratio improved from 71.6 to 21.0 (p < 0.0001) and IFNg:IL-10 ratio dropped from 24.5 to 12.5 (p < 0.0001). The improved ratios were achieved primarily by an increase in IL-10 expression (P = 0.0007), but also by a moderate decrease in stimulated TNFa expression (p = 0.008). Mean IFNg expression was unchanged (p = 0.42). On an individual basis CKR levels were normalised in 43 patients, improved in 12 and remained unchanged in 15. No significant differences in improvement were found between RM and IF subgroups.

Conclusions

Intracellular cytokine expression levels and ratios were modifiable by the supplement regime employed. Elevated cytokine ratios have been linked with adverse reproductive outcomes, and proposed treatments have included biological immunomodulators which antagonise TNFa, but come with significant associated cost implications and more importantly, cytotoxic side-effects. A dietary regime is more patient friendly and lower risk, while still achieving a similar effect in many patients.

Antioxidants for female subfertility

BACKGROUND

A couple may be considered to have fertility problems if they have been trying to conceive for over a year with no success. This may affect up to a quarter of all couples planning a child. It is estimated that for 40% to 50% of couples, subfertility may result from factors affecting women. Antioxidants are thought to reduce the oxidative stress brought on by these conditions. Currently, limited evidence suggests that antioxidants improve fertility, and trials have explored this area with varied results. This review assesses the evidence for the effectiveness of different antioxidants in female subfertility.

OBJECTIVES

To determine whether supplementary oral antioxidants compared with placebo, no treatment/standard treatment or another antioxidant improve fertility outcomes for subfertile women.

SEARCH METHODS

We searched the following databases (from their inception to September 2016) with no language or date restriction: Cochrane Gynaecology and Fertility Group (CGFG) specialised register, the Cochrane Central Register of Studies (CENTRAL CRSO), MEDLINE, Embase, PsycINFO, CINAHL and AMED. We checked reference lists of appropriate studies and searched for ongoing trials in the clinical trials registers.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared any type, dose or combination of oral antioxidant supplement with placebo, no treatment or treatment with another antioxidant, among women attending a reproductive clinic. We excluded trials comparing antioxidants with fertility drugs alone and trials that only included fertile women attending a fertility clinic because of male partner infertility.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected eligible studies, extracted the data and assessed the risk of bias of the included studies. The primary review outcome was live birth; secondary outcomes included clinical pregnancy rates and adverse events. We pooled studies using a fixed-effect model, and calculated odds ratios (ORs) with 95% confidence intervals (CIs) for the dichotomous outcomes of live birth, clinical pregnancy and adverse events. We assessed the overall quality of the evidence by applying GRADE criteria.

MAIN RESULTS

We included 50 trials involving 6510 women. Investigators compared oral antioxidants, including combinations of antioxidants, N-acetyl-cysteine, melatonin, L-arginine, myo-inositol, D-chiro-inositol, carnitine, selenium, vitamin E, vitamin B complex, vitamin C, vitamin D+calcium, CoQ10, pentoxifylline and omega-3-polyunsaturated fatty acids versus placebo, no treatment/standard treatment or another antioxidant.Very low-quality evidence suggests that antioxidants may be associated with an increased live birth rate compared with placebo or no treatment/standard treatment (OR 2.13, 95% CI 1.45 to 3.12, P > 0.001, 8 RCTs, 651 women, I2 = 47%). This suggests that among subfertile women with an expected live birth rate of 20%, the rate among women using antioxidants would be between 26% and 43%.Very low-quality evidence suggests that antioxidants may be associated with an increased clinical pregnancy rate compared with placebo or no treatment/standard treatment (OR 1.52, 95% CI 1.31 to 1.76, P < 0.001, 26 RCTs, 4271 women, I2 = 66%). This suggests that among subfertile women with an expected clinical pregnancy rate of 22%, the rate among women using antioxidants would be between 27% and 33%. Heterogeneity was moderately high.There was insufficient evidence to determine whether there was a difference between the groups in rates of miscarriage (OR 0.79, 95% CI 0.58 to 1.08, P = 0.14, 18 RCTs, 2834 women, I2 = 23%, very low quality evidence). This suggests that, among subfertile women with an expected miscarriage rate of 7%, use of antioxidants would be expected to result in a miscarriage rate of between 4% and 7%. There was also insufficient evidence to determine whether there was a difference between the groups in rates of multiple pregnancy (OR 1.00, 95% CI 0.73 to 1.38, P = 0.98, 8 RCTs, 2163 women, I2 = 4%, very low quality evidence). This suggests that among subfertile women with an expected multiple pregnancy rate of 8%, use of antioxidants would be expected to result in a multiple pregnancy rate between 6% and 11%. Likewise, there was insufficient evidence to determine whether there was a difference between the groups in rates of gastrointestinal disturbances (OR 1.55, 95% CI 0.47 to 5.10, P = 0.47, 3 RCTs, 343 women, I2 = 0%, very low quality evidence). This suggests that among subfertile women with an expected gastrointestinal disturbance rate of 2%, use of antioxidants would be expected to result in a rate between 1% and 11%. Overall adverse events were reported by 35 trials in the meta-analysis, but there was insufficient evidence to draw any conclusions.Only one trial reported on live birth, clinical pregnancy or adverse effects in the antioxidant versus antioxidant comparison, and no conclusions could be drawn.Very low-quality evidence suggests that pentoxifylline may be associated with an increased clinical pregnancy rate compared with placebo or no treatment (OR 2.07, 95% CI 1.20 to 3.56, P = 0.009, 3 RCTs, 276 women, I2 = 0%). This suggests that among subfertile women with an expected clinical pregnancy rate of 25%, the rate among women using pentoxifylline would be between 28% and 53%.There was insufficient evidence to determine whether there was a difference between the groups in rates of miscarriage (OR 1.34, 95% CI 0.46 to 3.90, P = 0.58, 3 RCTs, 276 women, I2 = 0%) or multiple pregnancy (OR 0.78, 95% CI 0.20 to 3.09, one RCT, 112 women, very low quality evidence). This suggests that among subfertile women with an expected miscarriage rate of 4%, the rate among women using pentoxifylline would be between 2% and 15%. For multiple pregnancy, the data suggest that among subfertile women with an expected multiple pregnancy rate of 9%, the rate among women using pentoxifylline would be between 2% and 23%.The overall quality of evidence was limited by serious risk of bias associated with poor reporting of methods, imprecision and inconsistency.

AUTHORS' CONCLUSIONS

In this review, there was very low-quality evidence to show that taking an antioxidant may provide benefit for subfertile women, but insufficient evidence to draw any conclusions about adverse events. At this time, there is limited evidence in support of supplemental oral antioxidants for subfertile women.

Interventions for the prevention of OHSS in ART cycles: an overview of Cochrane reviews

BACKGROUND

Ovarian hyperstimulation syndrome (OHSS) in assisted reproductive technology (ART) cycles is a treatment-induced disease that has an estimated prevalence of 20% to 33% in its mild form and 3% to 8% in its moderate or severe form. These numbers might even be higher for high-risk women such as those with polycystic ovaries or a high oocyte yield from ovum pickup.

OBJECTIVES

The objective of this overview is to identify and summarise all evidence from Cochrane systematic reviews on interventions for prevention or treatment of moderate, severe and overall OHSS in couples with subfertility who are undergoing ART cycles.

METHODS

Published Cochrane systematic reviews reporting on moderate, severe or overall OHSS as an outcome in ART cycles were eligible for inclusion in this overview. We also identified Cochrane submitted protocols and title registrations for future inclusion in the overview. The evidence is current to 12 December 2016. We identified reviews, protocols and titles by searching the Cochrane Gynaecology and Fertility Group Database of Systematic Reviews and Archie (the Cochrane information management system) in July 2016 on the effectiveness of interventions for outcomes of moderate, severe and overall OHSS. We undertook in duplicate selection of systematic reviews, data extraction and quality assessment. We used the AMSTAR (Assessing the Methodological Quality of Systematic Reviews) tool to assess the quality of included reviews, and we used GRADE methods to assess the quality of the evidence for each outcome. We summarised the characteristics of included reviews in the text and in additional tables.

MAIN RESULTS

We included a total of 27 reviews in this overview. The reviews were generally of high quality according to AMSTAR ratings, and included studies provided evidence that ranged from very low to high in quality. Ten reviews had not been updated in the past three years. Seven reviews described interventions that provided a beneficial effect in reducing OHSS rates, and we categorised one additional review as 'promising'. Of the effective interventions, all except one had no detrimental effect on pregnancy outcomes. Evidence of at least moderate quality indicates that clinicians should consider the following interventions in ART cycles to reduce OHSS rates.• Metformin treatment before and during an ART cycle for women with PCOS (moderate-quality evidence).• Gonadotrophin-releasing hormone (GnRH) antagonist protocol in ART cycles (moderate-quality evidence).• GnRH agonist (GnRHa) trigger in donor oocyte or 'freeze-all' programmes (moderate-quality evidence). Evidence of low or very low quality suggests that clinicians should consider the following interventions in ART cycles to reduce OHSS rates.• Clomiphene citrate for controlled ovarian stimulation in ART cycles (low-quality evidence).• Cabergoline around the time of human chorionic gonadotrophin (hCG) administration or oocyte pickup in ART cycles (low-quality evidence).• Intravenous fluids (plasma expanders) around the time of hCG administration or oocyte pickup in ART cycles (very low-quality evidence).• Progesterone for luteal phase support in ART cycles (low-quality evidence).• Coasting (withholding gonadotrophins) - a promising intervention that needs to be researched further for reduction of OHSS.On the basis of this overview, we must conclude that evidence is currently insufficient to support the widespread practice of embryo cryopreservation.

AUTHORS' CONCLUSIONS

Currently, 27 reviews in the Cochrane Library were conducted to report on or to try to report on OHSS in ART cycles. We identified four review protocols but no new registered titles that can potentially be included in this overview in the future. This overview provides the most up-to-date evidence on prevention of OHSS in ART cycles from all currently published Cochrane reviews on ART. Clinicians can use the evidence summarised in this overview to choose the best treatment regimen for individual patients - a regimen that not only reduces the chance of developing OHSS but does not compromise other outcomes such as pregnancy or live birth rate. Review results, however, are limited by the lack of recent primary studies or updated reviews. Furthermore, this overview can be used by policymakers in developing local and regional protocols or guidelines and can reveal knowledge gaps for future research.

Lifestyle and in vitro fertilization: what do patients believe?

Background

Patients have many beliefs regarding lifestyle factors and IVF outcomes.

Methods

Observational study of 208 IVF patients at an academic infertility center. Main outcome measures were perceived influence of various lifestyle factors assessed by multivariable logistic regression and p-value tests for linear trend (P_t).

Results

A majority of participants believed that there were many women’s lifestyle choices that were influential, compared to fewer male factors (cessation of tobacco (72 %), alcohol (69 %), caffeine (62 %), and use of vitamins (88 %)). Compared to participants with less education, participants with a higher education level were less likely to believe vitamins were helpful and some alcohol use was not harmful. As income decreased, participants were less likely to consider dietary factors contributory to IVF success, such as women (p-trend, p = 0.02) and men (p-trend, p = 0.009) consuming a full-fat dairy diet. Participants’ beliefs were most commonly influenced by physicians (84 %) and the internet (71 %).

Conclusions

Patients believed many lifestyle factors are associated with IVF success. Understanding patients’ assumptions regarding the effect of lifestyle factors on IVF success may better allow physicians to counsel patients about IVF outcomes.

Electronic supplementary material

The online version of this article (doi:10.1186/s40738-016-0026-5) contains supplementary material, which is available to authorized users.

Myeloperoxidase as a Potential Target in Women With Endometriosis Undergoing IVF

As infertility is intimately associated with endometriosis, the levels of myeloperoxidase (MPO), a leukocyte enzyme and an oxidative stress marker, were determined in a case-control prospective study of 68 women with and without endometriosis undergoing in vitro fertilization in the outpatient fertility center within a tertiary care academic medical center. Measured values included plasma and follicular fluid (FF) concentrations of MPO, plasma estradiol, as well as oocyte quality, fertilization, implantation, and pregnancy rates in these women. In FF (mean ± standard error of mean [SEM]), the MPO concentrations (ng/mL) for controls were 4.3 ± 0.37, mild endometriosis (stages I-II) 3.9 ± 0.17, and moderate/severe endometriosis (stages III-IV) 16.6 ± 12.5 ( P < 0.0143). In FF, among patients supplemented with vitamins E and C, the MPO levels decreased significantly only in moderate/severe endometriosis from 25.3 ± 22.0 ng/mL to 4.9 ± 1.61 ng/mL, respectively. Plasma levels of MPO between groups did not change. Outcome data revealed a trend toward decreased percentage of mature oocytes, implantation rate, and clinical pregnancy rate with severity of endometriosis and MPO levels. Myeloperoxidase may be a potential oxidative stress target for endometriosis-associated infertility.

Improvement of gamete quality by stimulating and feeding the endogenous antioxidant system: mechanisms, clinical results, insights on gene-environment interactions and the role of diet

Oxidative damage triggers extensive repair in gametes and thereafter in the zygote but it results in clinically relevant damage when affecting the maturation of the gametes chromatin, i.e. padlocking and epigenetic marking. It associates with defective DNA methylation and/or with oxidation of the methyl marks leading to derangement of gamete epigenetics, defects of chromatin condensation and aneuploidy. A proper feed to the one carbon cycle has the potential to stimulate the endogenous antioxidant defences, i.e. gluthatione synthesis, and to activate compensative homeostatic mechanisms restoring both the oxy-redox balance and DNA methylation, which are indeed strictly cross-regulated. This has been shown to produce measurable clinical improvements of male reproductive potential in pilot studies herein summarised. However, the effects of dietary habits and of supplementations are variable according to the individual genetic substrate, as genetic variants of several of the concerned enzymes occur with high frequency. Individual risk assessments and personalised interventions are still difficult to implement, in the meantime, a very varied diet may facilitate metabolic compensation in the majority of the cases. This review aims to report on the mechanisms of damage, on the opportunities to modulate the physiologic oxy-redox homeostasis by means of a varied diet or dietary supplements and on the open issues related to the genetic variability of the population.

Oxidative stress in pregnancy and reproduction

Oxidative stress is implicated in the pathophysiology of many reproductive complications including infertility, miscarriage, pre-eclampsia, fetal growth restriction and preterm labour. The presence of excess reactive oxygen species can lead to cellular damage of deoxyribonucleic acids, lipids and proteins. Antioxidants protect cells from peroxidation reactions, limiting cellular damage and helping to maintain cellular membrane integrity. There is overwhelming evidence for oxidative stress causing harm in reproduction. However, there is sparse evidence that supplementation with commonly used antioxidants (mostly vitamins C and E) makes any difference in overcoming oxidative stress or reversing disease processes. There may be potential for antioxidant therapy to ameliorate or prevent disease, but this requires a thorough understanding of the mechanism of action and specificity of currently used antioxidants.

Impact of Prunus Cerasus on PGR and HAS2 in Cumulus Cells and Fertility Outcome

PURPOSE

Cumulus cells have a critical role in normal oocyte development and fertilization. Prunus cerasus is an anthocyanin rich berry and performs strong antioxidant activity. The present study set to determine if Prunus cerasus can affect expression of HAS2 (hyaluronan synthase 2) and progesterone receptor in Cumulus cells and its consequences outcome of the in vitro fertilization.

METHODS

60 female and 15 male adult mice were used for mating and IVF (in vitro fertilization). Prunus cerasus extraction was added to the diet of female mice for 30 days. Ovulation induction and oocytes collection were done as routine. The cumulus cells were dissected apart, and the expression of progesterone receptor and HAS2 was detected using RT-PCR (real-time polymerase chain reaction). Fertilization rate was evaluated by IVF. All data were analyzed using t-test.

RESULTS

Data was showed that expression of progesterone receptor and HAS2 in cumulus cells of mice that received prunus cerasus increased. Moreover, oocyte fertilization rate also increased significantly.

CONCLUSION

Prunus cerasus as an antioxidant natural can become an important medication for improving oocyte quality and opening new opportunities for infertility treatment. It is concluded that Prunus cerasus consumption could improve fertility rate by increasing progesterone receptor and HAS2 activity in cumulus cells.

Add-ons in IVF programme - Hype or Hope?

A series of new technologies and adjuvant therapies have been advocated in order to improve the success of IVF treatment. Dehydro-epiandrostenedione, growth hormones, Coenzyme Q 10, calcium ionosphores, immune therapy, heparin, low-dose aspirin, and vasodilators are among commonly prescribed pharmacological adjuvants. New technologies that are proposed to improve IVF outcomes include advanced sperm selection procedures, time- lapse embryo monitoring, preimplantation genetic screening, assisted hatching endometrial injury or embryo-glue. This review looked into current evidence to justify the use of these co-interventions and whether some of them can still be offered while awaiting more robust evidence to con rm or refute their role.

Assisted reproductive technology: an overview of Cochrane Reviews

BACKGROUND

As many as one in six couples will encounter problems with fertility, defined as failure to achieve a clinical pregnancy after regular intercourse for 12 months. Increasingly, couples are turning to assisted reproductive technology (ART) for help with conceiving and ultimately giving birth to a healthy live baby of their own. Fertility treatments are complex, and each ART cycle consists of several steps. If one of the steps is incorrectly applied, the stakes are high as conception may not occur. With this in mind, it is important that each step of the ART cycle is supported by good evidence from well-designed studies.

OBJECTIVES

To summarise the evidence from Cochrane systematic reviews on procedures and treatment options available to couples with subfertility undergoing assisted reproductive technology (ART).

METHODS

Published Cochrane systematic reviews of couples undergoing ART (in vitro fertilisation or intracytoplasmic sperm injection) were eligible for inclusion in the overview. We also identified Cochrane reviews in preparation, for future inclusion.The outcomes of the overview were live birth (primary outcome), clinical pregnancy, multiple pregnancy, miscarriage and ovarian hyperstimulation syndrome (secondary outcomes). Studies of intrauterine insemination and ovulation induction were excluded.Selection of systematic reviews, data extraction and quality assessment were undertaken in duplicate. Review quality was assessed by using the AMSTAR tool. Reviews were organised by their relevance to specific stages in the ART cycle. Their findings were summarised in the text and data for each outcome were reported in 'Additional tables'.

MAIN RESULTS

Fifty-nine systematic reviews published in The Cochrane Library up to July 2015 were included. All were high quality. Thirty-two reviews identified interventions that were effective (n = 19) or promising (n = 13), 14 reviews identified interventions that were either ineffective (n = 2) or possibly ineffective (n = 12), and 13 reviews were unable to draw conclusions due to lack of evidence.An additional 11 protocols and five titles were identified for future inclusion in this overview.

AUTHORS' CONCLUSIONS

This overview provides the most up to date evidence on ART cycles from systematic reviews of randomised controlled trials. Fertility treatments are costly and the stakes are high. Using the best available evidence to optimise outcomes is best practice. The evidence from this overview could be used to develop clinical practice guidelines and protocols for use in daily clinical practice, in order to improve live birth rates and reduce rates of multiple pregnancy, cycle cancellation and ovarian hyperstimulation syndrome.

Dietary factors and luteal phase deficiency in healthy eumenorrheic women

STUDY QUESTION

Are prospectively assessed dietary factors, including overall diet quality, macronutrients and micronutrients, associated with luteal phase deficiency (LPD) in healthy reproductive aged women with regular menstrual cycles?

SUMMARY ANSWER

Mediterranean Diet Score (MDS), fiber and isoflavone intake were positively associated with LPD while selenium was negatively associated with LPD after adjusting for age, percentage body fat and total energy intake.

WHAT IS KNOWN ALREADY

LPD may increase the risk of infertility and early miscarriage. Prior research has shown positive associations between LPD and low energy availability, either through high dietary restraint alone or in conjunction with high energy expenditure via exercise, but few studies with adequate sample sizes have been conducted investigating dietary factors and LPD among healthy, eumenorrheic women.

STUDY DESIGN, SIZE, DURATION

The BioCycle Study (2005-2007) prospectively enrolled 259 women from Western New York state, USA, and followed them for one (n = 9) or two (n = 250) menstrual cycles.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Women aged 18-44 years, with self-reported BMI between 18 and 35 kg/m(2) and cycle lengths between 21 and 35 days, were included in the study. Participants completed baseline questionnaires, four 24-h dietary recalls per cycle and daily diaries capturing vigorous exercise, perceived stress and sleep; they also provided up to eight fasting serum samples during clinic visits timed to specific phases of the menstrual cycle using a fertility monitor. Cycles were included for this analysis if the peak serum luteal progesterone was >1 ng/ml and a urine or serum LH surge was detected. Associations between prospectively assessed diet quality, macronutrients and micronutrients and LPD (defined as luteal duration <10 days) were evaluated using generalized linear models adjusting for age, percentage body fat and total energy intake.

MAIN RESULTS AND THE ROLE OF CHANCE

LPD occurred in 41 (8.9%) of the 463 cycles from 246 women in the final analysis. After adjusting for age, percentage body fat and total energy intake, LPD was positively associated with MDS, adjusted odds ratio (aOR): 1.70 (95% confidence interval [CI]: 1.17, 2.48), P = 0.01. In separate macro- and micronutrient adjusted models, increased fiber and isoflavone intake showed modest positive associations with LPD: fiber (per g), aOR: 1.10 (95% CI: 0.99, 1.23), P = 0.07; and isoflavones (per 10 mg), aOR: 1.38 (95% CI: 0.99, 1.92), P = 0.06. In contrast, selenium (per 10 mcg) was inversely associated with LPD, aOR: 0.80 (95% CI: 0.65, 0.97), P = 0.03. Additional adjustments for relevant lifestyle factors including vigorous exercise, perceived stress and sleep did not appreciably alter estimates.

LIMITATIONS, REASONS FOR CAUTION

The number of LPD cycles was limited, and thus these findings are exploratory. We relied on participant self-report of their medical history to apply exclusion criteria; it is possible that we admitted to the study women with a gynecologic or medical disease who were unaware of their diagnosis.

WIDER IMPLICATIONS OF THE FINDINGS

Our study suggests that diet quality may be associated with LPD among healthy eumenorrheic women. As LPD may contribute to infertility and early miscarriage, further research is warranted to elucidate how dietary factors, such as MDS, may influence LPD. The inverse association we found with selenium is supported by previous research and deserves further investigation to determine whether this finding has pathophysiologic and therapeutic implications.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by the Intramural Research Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health. No competing interests declared.

Oocyte aging underlies female reproductive aging: biological mechanisms and therapeutic strategies

In recent years, postponement of marriage and childbearing in women of reproductive age has led to an increase in the incidence of age-related infertility. The reproductive aging process in women is assumed to occur due to a decrease in both the quantity and quality of the oocytes, with the ultimate result being a decline in fecundity. This age-related decline in fecundity is strongly dependent on oocyte quality, which is critical for fertilization and subsequent embryo development. Aged oocytes display increased chromosomal abnormality and dysfunction of cellular organelles, both of which factor into oocyte quality. In particular, mitochondrial dysfunction has been suggested as a major contributor to the reduction in oocyte quality as well as to chromosomal abnormalities in aged oocytes and embryos. Participation of oxidative stress in the oocyte aging process has been proposed because oxidative stress has the capacity to induce mitochondrial dysfunction and directly damage many intracellular components of the oocytes such as lipids, protein, and DNA. In an attempt to improve mitochondrial function in aged oocytes, several therapeutic strategies have been investigated using both animal models and assisted reproductive technology. Here, we review the biological mechanisms and present status of therapeutic strategies in the female reproductive aging field and indicate possible future therapeutic strategies.

Heme oxygenase and the immune system in normal and pathological pregnancies

Normal pregnancy is an immunotolerant state. Many factors, including environmental, socioeconomic, genetic, and immunologic changes by infection and/or other causes of inflammation, may contribute to inter-individual differences resulting in a normal or pathologic pregnancy. In particular, imbalances in the immune system can cause many pregnancy-related diseases, such as infertility, abortions, pre-eclampsia, and preterm labor, which result in maternal/fetal death, prematurity, or small-for-gestational age newborns. New findings imply that myeloid regulatory cells and regulatory T cells (Tregs) may mediate immunotolerance during normal pregnancy. Effector T cells (Teffs) have, in contrast, been implicated to cause adverse pregnancy outcomes. Furthermore, feto-maternal tolerance affects the developing fetus. It has been shown that the Treg/Teff balance affects litter size and adoptive transfer of pregnancy-induced Tregs can prevent fetal rejection in the mouse. Heme oxygenase-1 (HO-1) has a protective role in many conditions through its anti-inflammatory, anti-apoptotic, antioxidative, and anti-proliferative actions. HO-1 is highly expressed in the placenta and plays a role in angiogenesis and placental vascular development and in regulating vascular tone in pregnancy. In addition, HO-1 is a major regulator of immune homeostasis by mediating crosstalk between innate and adaptive immune systems. Moreover, HO-1 can inhibit inflammation-induced phenotypic maturation of immune effector cells and pro-inflammatory cytokine secretion and promote anti-inflammatory cytokine production. HO-1 may also be associated with T-cell activation and can limit immune-based tissue injury by promoting Treg suppression of effector responses. Thus, HO-1 and its byproducts may protect against pregnancy complications by its immunomodulatory effects, and the regulation of HO-1 or its downstream effects has the potential to prevent or treat pregnancy complications and prematurity.

Assisted reproductive technology: an overview of Cochrane reviews

BACKGROUND

As many as one in six couples will encounter problems with fertility, defined as failure to achieve a clinical pregnancy after regular intercourse for 12 months. Increasingly, couples are turning to assisted reproductive technology (ART) for help with conceiving and ultimately giving birth to a healthy live baby of their own. Fertility treatments are complex, and each ART cycle consists of several steps. If one of the steps is incorrectly applied, the stakes are high as conception may not occur. With this in mind, it is important that each step of the ART cycle is supported by good evidence from well-designed studies.

OBJECTIVES

To summarise the evidence from Cochrane systematic reviews on procedures and treatment options available to couples with subfertility undergoing assisted reproductive technology (ART).

METHODS

Published Cochrane systematic reviews of couples undergoing ART (in vitro fertilisation or intracytoplasmic sperm injection) were eligible for inclusion in the overview. We also identified Cochrane reviews in preparation, for future inclusion.The outcomes of the overview were live birth (primary outcome), clinical pregnancy, multiple pregnancy, miscarriage and ovarian hyperstimulation syndrome (secondary outcomes). Studies of intrauterine insemination and ovulation induction were excluded.Selection of systematic reviews, data extraction and quality assessment were undertaken in duplicate. Review quality was assessed by using the AMSTAR tool. Reviews were organised by their relevance to specific stages in the ART cycle. Their findings were summarised in the text and data for each outcome were reported in 'Additional tables'.

MAIN RESULTS

Fifty-eight systematic reviews published in The Cochrane Library were included. All were high quality. Thirty-two reviews identified interventions that were effective (n = 19) or promising (n = 13), 14 reviews identified interventions that were either ineffective (n = 3) or possibly ineffective (n=11), and 12 reviews were unable to draw conclusions due to lack of evidence.An additional 11 protocols and one title were identified for future inclusion in this overview.

AUTHORS' CONCLUSIONS

This overview provides the most up to date evidence on ART cycles from systematic reviews of randomised controlled trials. Fertility treatments are costly and the stakes are high. Using the best available evidence to optimise outcomes is best practice. The evidence from this overview could be used to develop clinical practice guidelines and protocols for use in daily clinical practice, in order to improve live birth rates and reduce rates of multiple pregnancy, cycle cancellation and ovarian hyperstimulation syndrome.

Modifiable Risk Factors and Infertility: What are the Connections?

Infertility is a relatively common condition, greatly affecting couples medically and psychologically. Although infertility treatment is safe, it can be time-intensive, expensive and increase the risk of multiple gestations. Thus, to reduce costs and risks, couples may initially consider lifestyle change to increase their fertility and chances of pregnancy. For many of the diet factors studied (for example: caffeine, soy, protein, iron), there are conflicting data. However, there are some items men and women consume that are detrimental to fertility, such as alcohol and tobacco. The data on exercise are varied but may have an effect on ovulation and fertility - positive or negative. Body mass index appears to impact fertility also, with obesity in both men and women negatively affecting pregnancy rates. In addition, there remains concern and a growing body of research on environmental toxin exposures and reproductive health. Finally, supporting patients through infertility diagnosis and treatment is critical, as psychological stress may impact conception. It is imperative that the relationship between lifestyle factors and fertility continue to be explored as to lessen the morbidity associated with infertility.

Utility of antioxidants during assisted reproductive techniques: an evidence based review

Assisted reproductive technology (ART) is a common treatment of choice for many couples facing infertility issues, be it due to male or female factor, or idiopathic. Employment of ART techniques, however, come with its own challenges as the in vitro environment is not nearly as ideal as the in vivo environment, where reactive oxygen species (ROS) build-up leading to oxidative stress is kept in check by the endogenous antioxidants system. While physiological amounts of ROS are necessary for normal reproductive function in vivo, in vitro manipulation of gametes and embryos exposes these cells to excessive ROS production either by endogenous or exogenous environmental factors. In this review, we discuss the sources of ROS in an in vitro clinical setting and the influence of oxidative stress on gamete/embryo quality and the outcome of IVF/ICSI. Sources of ROS and different strategies of overcoming the excessive generation of ROS in vitro are also highlighted. Endogenously, the gametes and the developing embryo become sources of ROS. Multiple exogenous factors act as potential sources of ROS, including exposure to visible light, composition of culture media, pH and temperature, oxygen concentration, centrifugation during spermatozoa preparation, ART technique involving handling of gamete/embryo and cryopreservation technique (freeze/thawing process). Finally, the use of antioxidants as agents to minimize ROS generation in the in vitro environment and as oral therapy is highlighted. Both enzymatic and non-enzymatic antioxidants are discussed and the outcome of studies using these antioxidants as oral therapy in the male or female or its use in vitro in media is presented. While results of studies using certain antioxidant agents are promising, the current body of evidence as a whole suggests the need for further well-designed and larger scale randomized controlled studies, as well as research to minimize oxidative stress conditions in the clinical ART setting.

Melatonin: shedding light on infertility?--A review of the recent literature

In recent years, the negative impact of oxidative stress on fertility has become widely recognised. Several studies have demonstrated its negative effect on the number and quality of retrieved oocytes and embryos following in-vitro fertilisation (IVF). Melatonin, a pineal hormone that regulates circadian rhythms, has also been shown to exhibit unique oxygen scavenging abilities. Some studies have suggested a role for melatonin in gamete biology. Clinical studies also suggest that melatonin supplementation in IVF may lead to better pregnancy rates. Here we present a critical review and summary of the current literature and provide suggestions for future well designed clinical trials.

Antioxidants for male subfertility

BACKGROUND

Between 30% to 80% of male subfertility cases are considered to be due to the damaging effects of oxidative stress on sperm and 1 man in 20 will be affected by subfertility. Antioxidants are widely available and inexpensive when compared to other fertility treatments and many men are already using these to improve their fertility. It is thought that oral supplementation with antioxidants may improve sperm quality by reducing oxidative stress. Pentoxifylline, a drug that acts like an antioxidant, was also included in this review.  

OBJECTIVES

This Cochrane review aimed to evaluate the effectiveness and safety of oral supplementation with antioxidants for subfertile male partners in couples seeking fertility assistance.

SEARCH METHODS

We searched the Cochrane Menstrual Disorders and Subfertility Group Specialised Register, CENTRAL, MEDLINE, EMBASE, CINAHL, PsycINFO and AMED databases (from inception until January 2014); trial registers; sources of unpublished literature and reference lists. An updated search was run in August 2014 when potentially eligible studies were placed in 'Studies awaiting assessment'.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing any type or dose of antioxidant supplement (single or combined) taken by the subfertile male partner of a couple seeking fertility assistance with a placebo, no treatment or another antioxidant.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected eligible studies, extracted the data and assessed the risk of bias of the included studies. The primary review outcome was live birth; secondary outcomes included clinical pregnancy rates, adverse events, sperm DNA fragmentation, sperm motility and concentration. Data were combined, where appropriate, to calculate pooled odds ratios (ORs) or mean differences (MD) and 95% confidence intervals (CIs). Statistical heterogeneity was assessed using the I(2) statistic. We assessed the overall quality of the evidence for the main outcomes using GRADE methods.  

MAIN RESULTS

This updated review included 48 RCTs that compared single and combined antioxidants with placebo, no treatment or another antioxidant in a population of 4179 subfertile men. The duration of the trials ranged from 3 to 26 weeks with follow up ranging from 3 weeks to 2 years. The men were aged from 20 to 52 years. Most of the men enrolled in these trials had low total sperm motility and sperm concentration. One study enrolled men after varicocelectomy, one enrolled men with a varicocoele, and one recruited men with chronic prostatitis. Three trials enrolled men who, as a couple, were undergoing in vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI) and one trial enrolled men who were part of a couple undergoing intrauterine insemination (IUI). Funding sources were stated by 15 trials. Four of these trials stated that funding was from a commercial source and the remaining 11 obtained funding through non-commercial avenues or university grants. Thirty-three trials did not report any funding sources.A limitation of this review was that in a sense we had included two different groups of trials, those that reported on the use of antioxidants and the effect on live birth and clinical pregnancy, and a second group that reported on sperm parameters as their primary outcome and had no intention of reporting the primary outcomes of this review. We included 25 trials reporting on sperm parameters and only three of these reported on live birth or clinical pregnancy. Other limitations included poor reporting of study methods, imprecision, the small number of trials providing usable data, the small sample size of many of the included studies and the lack of adverse events reporting. The evidence was graded as 'very low' to 'low'. The data were current to 31 January 2014.Live birth: antioxidants may have increased live birth rates (OR 4.21, 95% CI 2.08 to 8.51, P< 0.0001, 4 RCTs, 277 men, I(2) = 0%, low quality evidence). This suggests that if the chance of a live birth following placebo or no treatment is assumed to be 5%, the chance following the use of antioxidants is estimated to be between 10% and 31%. However, this result was based on only 44 live births from a total of 277 couples in four small studies.Clinical pregnancy rate: antioxidants may have increased clinical pregnancy rates (OR 3.43, 95% CI 1.92 to 6.11, P < 0.0001, 7 RCTs, 522 men, I(2) = 0%, low quality evidence). This suggests that if the chance of clinical pregnancy following placebo or no treatment is assumed to be 6%, the chance following the use of antioxidants is estimated at between 11% and 28%. However, there were only seven small studies in this analysis and the quality of the evidence was rated as low.Miscarriage: only three trials reported on this outcome and the event rate was very low. There was insufficient evidence to show whether there was a difference in miscarriage rates between the antioxidant and placebo or no treatment groups (OR 1.74, 95% CI 0.40 to 7.60, P = 0.46, 3 RCTs, 247 men, I(2) = 0%, very low quality evidence). The findings suggest that in a population of subfertile men with an expected miscarriage rate of 2%, use of an antioxidant would result in the risk of a miscarriage lying between 1% and 13%.Gastrointestinal upsets: there was insufficient evidence to show whether there was a difference in gastrointestinal upsets when antioxidants were compared to placebo or no treatment as the event rate was very low (OR 1.60, 95% CI 0.47 to 5.50, P = 0.46, 6 RCTs, 429 men, I(2) = 0%).We were unable to draw any conclusions from the antioxidant versus antioxidant comparison as not enough trials compared the same interventions.

AUTHORS' CONCLUSIONS

There is low quality evidence from only four small randomised controlled trials suggesting that antioxidant supplementation in subfertile males may improve live birth rates for couples attending fertility clinics. Low quality evidence suggests that clinical pregnancy rates may increase. There is no evidence of increased risk of miscarriage but this is uncertain as the evidence is of very low quality. Data were lacking on other adverse effects. Further large well-designed randomised placebo-controlled trials are needed to clarify these results.

Melatonin supplementation during controlled ovarian stimulation for women undergoing assisted reproductive technology: systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

To examine the best evidence available regarding the effect of melatonin supplementation during controlled ovarian stimulation (COS) on the main assisted reproductive technology (ART) outcomes.

DESIGN

Systematic review and meta-analysis of randomized clinical trials (RCT).

SETTING

Not applicable.

PATIENT(S)

Women undergoing COS for ART.

INTERVENTION(S)

Melatonin supplementation during COS for women undergoing ART.

MAIN OUTCOME MEASURE(S)

Live birth rate, clinical pregnancy rate, number of retrieved oocytes, miscarriage rate, ovarian hyperstimulation syndrome (OHSS) rate, and number of congenital abnormalities. Comparisons were performed using risk ratio (RR) or mean difference (MD).

RESULT(S)

Five RCTs were considered eligible, and their data were extracted and included in a meta-analysis. No studies reported live-birth or congenital abnormalities. Our estimates were imprecise for distinguishing between no effect and benefit considering clinical pregnancy (RR, 1.21; 95% confidence interval [CI], 0.98-1.50, five studies, 680 women, low quality-evidence) and the number of oocytes retrieved (MD, 0.6; 95% CI, -0.2-2.2, five studies, 680 women, low quality-evidence). Our estimates were imprecise for distinguishing among harm, no effect, and benefit considering miscarriage (RR, 1.07; 95% CI, 0.43-2.68, two studies, 143 clinical pregnancies, low quality-evidence) and interventions to reduce the risk of OHSS (RR,1.01; 95% CI, 0.33-3.08, one study, 358 women, low quality-evidence).

CONCLUSION(S)

More studies investigating the role of melatonin supplementation are still needed before recommending its use in clinical practice.

Assisted reproductive technology: an overview of Cochrane Reviews

BACKGROUND

As many as one in six couples will encounter problems with fertility, defined as failure to achieve a clinical pregnancy after regular intercourse for 12 months. Increasingly, couples are turning to assisted reproductive technology (ART) for help with conceiving and ultimately giving birth to a healthy live baby of their own. Fertility treatments are complex, and each ART cycle consists of several steps. If one of the steps is incorrectly applied, the stakes are high as conception may not occur. With this in mind, it is important that each step of the ART cycle is supported by good evidence from well-designed studies.

OBJECTIVES

To summarise the evidence from Cochrane systematic reviews on procedures and treatment options available to couples with subfertility undergoing assisted reproductive technology (ART).

METHODS

Published Cochrane systematic reviews of couples undergoing ART (in vitro fertilisation or intracytoplasmic sperm injection) were eligible for inclusion in the overview. We also identified Cochrane reviews in preparation, for future inclusion.The outcomes of the overview were live birth (primary outcome), clinical pregnancy, multiple pregnancy, miscarriage and ovarian hyperstimulation syndrome (secondary outcomes). Studies of intrauterine insemination and ovulation induction were excluded.Selection of systematic reviews, data extraction and quality assessment were undertaken in duplicate. Review quality was assessed by using the AMSTAR tool. Reviews were organised by their relevance to specific stages in the ART cycle. Their findings were summarised in the text and data for each outcome were reported in 'Additional tables'.

MAIN RESULTS

Fifty-four systematic reviews published in The Cochrane Library were included. All were high quality. Thirty reviews identified interventions that were effective (n = 18) or promising (n = 12), 13 reviews identified interventions that were either ineffective (n = 3) or possibly ineffective (n=10), and 11 reviews were unable to draw conclusions due to lack of evidence.An additional 15 protocols and two titles were identified for future inclusion in this overview.

AUTHORS' CONCLUSIONS

This overview provides the most up to date evidence on ART cycles from systematic reviews of randomised controlled trials. Fertility treatments are costly and the stakes are high. Using the best available evidence to optimise outcomes is best practice. The evidence from this overview could be used to develop clinical practice guidelines and protocols for use in daily clinical practice, in order to improve live birth rates and reduce rates of multiple pregnancy, cycle cancellation and ovarian hyperstimulation syndrome.