Assisted Reproductive Outcomes Research Articles

Efficacy of transdermal testosterone in assisted reproduction outcome of poor responders

Efficacy of transdermal testosterone in assisted reproduction outcome of poor responders

Association between early embryo morphokinetics plus cumulus cell gene expression and assisted reproduction outcomes in polycystic ovary syndrome women.

Can a combination of time-lapse morphokinetic parameters and cumulus cell gene expression in polycystic ovary syndrome (PCOS) women be used to predict assisted reproductive treatment outcome? A total of 547 embryos from 100 intracytoplasmic sperm injection (ICSI) cycles were evaluated. Fifty women with PCOS and 50 women who were categorized as tubal factor infertility were recruited. Time-lapse records were annotated for time to pronuclear fading (tPNf), time to 2 to 8 cells (t2-t8), reverse cleavage, direct cleavage and also for the presence of multinucleation. Expression levels of three genes involved in mitotic divisions, diaphanous-related formin 2 (DIAPH2), nibrin (NBN) and NIMA-related protein kinase (NEK4), were measured in 100 associated cumulus cell samples using quantitative real-time polymerase chain reaction. Expression of DIAPH2 and NBN was significantly higher in the embryos of PCOS patients that resulted in implantation, biochemical and clinical pregnancies as well as live birth compared with embryos that were negative for these outcomes (P<0.01). However, in the tubal factor group, NBN gene expression was significantly higher in embryos resulting in biochemical pregnancy, clinical pregnancy and live birth (P<0.01) only. Multivariate logistic regression analysis showed that tPNf together with DIAPH2 gene expression were independent prognostic factors of clinical pregnancy rate and live birth in both groups. Some time-lapse embryo parameters may be related to cumulus gene expression and clinical outcome. Furthermore, the expressions of cumulus cell genes involved in mitotic divisions are significantly associated with ICSI outcome using Day 3 embryo transfer.

Do lifestyle and Physical Factors Influence Fertility Potential and Assisted Reproduction Outcomes in Infertile Men?

Background: The effects of lifestyle and physical factors on male fertility potential are controversial and these disagreements have increased public and research attention. Objectives: This study was planned to evaluate the effects of modifiable lifestyle and physical factors on the semen quality and assisted reproductive outcomes. Methods: This prospective study evaluated lifestyle and physical factors in 306 infertile men under an assisted reproductive program such as body mass index, age, abstinence time, tobacco smoking, varicocele treatment, physical activity, caffeine consumption, and the use of cell phones, as well as sperm chromatin integrity and condensation, semen parameters, and assisted reproductive outcomes between 2016 and 2018. Statistical analysis was performed using SPSS version 20 and CorrelationAttributeEval and Ranker modules of WEKA software were applied to evaluate the effect of each feature/factor of men on the biochemical pregnancy rate. Results: A negative association was seen between the total sperm count and abstinence time (< 3 days, P = 0.02) and caffeine consumption (> 4 cups/d, P = 0.03). A decreased sperm concentration, normal morphology, motility, and chromatin normality were found in the categories of older age (> 35-years-old) and elevated BMI (> 30, P = 0.03). The poor embryo quality (grade D) and increased spontaneous abortion were found in men with high age, BMI, caffeine consumers, and smokers. The effects of smoking, age, and BMI weighed more than the effects of other parameters on biochemical pregnancy. Conclusions: Factors such as aging, elevated BMI, smoking, and high consumption of caffeine via affecting sperm parameters and increasing DNA damage may affect assisted reproductive outcomes (e.g., poor embryo quality and high abortion).

Assisted reproductive outcomes in women with different polycystic ovary syndrome phenotypes.

To explore assisted reproductive outcomes among women with different polycystic ovary syndrome (PCOS) phenotypes. A retrospective cohort study included women with PCOS who were treated at Yazd Research and Clinical Center for Infertility, Yazd, Iran, using the GnRH antagonist protocol between April 1, 2015, and August 31, 2017. Clinical pregnancy was the primary outcome, and chemical pregnancy, implantation rate, fertilization rate, and spontaneous abortion rate, were the secondary outcomes that were evaluated among four defined phenotypes of women with PCOS. Significant differences were observed between the phenotypes for the levels of luteinizing hormone, anti-Müllerian hormone, fasting blood sugar, and total testosterone concentration; similarly, the percentage of women with luteinizing hormone/follicle stimulating hormone ratio of at least 2.5 differed between PCOS phenotypes (all P<0.001). There were also significant differences in estradiol level (P<0.001) and the number of matured follicles (P=0.002) between different phenotypes. No significant differences were observed in the fertilization and implantation rates, as well as chemical and clinical pregnancy rates (all P>0.05). No significant differences were observed in assisted reproductive technique outcome among women with different phenotypes of PCOS undergoing frozen-thawed embryo transfer.

Alterations of sex determination pathways in the genital ridges of males with limited Y chromosome genes†.

We previously demonstrated that in the mouse only two Y chromosome genes are required for a male to produce an offspring with the help of assisted reproduction technologies (ART): testis determinant Sry and spermatogonial proliferation factor Eif2s3y. Subsequently, we have shown that the function of these genes can be replaced by transgenic overexpression of their homologs, autosomally encoded Sox9 and X-chromosome encoded Eif2s3x. Males with Y chromosome contribution limited to two (XEif2s3yOSry), one (XEif2s3yOSox9 and XOSry,Eif2s3x), and no genes (XOSox9,Eif2s3x) produced haploid germ cells and sired offspring after ART. However, despite successful assisted reproductive outcome, they had smaller testes and displayed abnormal development of the seminiferous epithelium and testicular interstitium. Here we explored whether these testicular defects originated from altered pro-testis and pro-ovary factor signaling in genital ridges at the time of sex determination. Timed pregnancies were generated to obtain transgenic XEif2s3yOSry, XEif2s3yOSox9, XOSry,Eif2s3x, XOSox9,Eif2s3x, and wild-type XX and XY fetuses at 12.5 days post coitum. Dissected genital ridges were assessed for their morphology and anatomy, and expression of pro-testis and pro-ovary transcripts. All transgenic males displayed incomplete masculinization of gonadal shape, impaired development of testicular cords and gonadal vasculature, and decreased expression of factors promoting male pathway. Fetal gonad masculinization was more effective when sex determination was driven by the Sry transgene, in the presence of Y chromosome genes, and to a lesser extent a double dosage of X genes. The study adds to the understanding of the role of Y chromosome genes and their homologs during sex determination.

The attractive effect of DNA fragmentation index on assisted reproductive treatment outcome: a large sample size and well-controlled retrospective study

The attractive effect of DNA fragmentation index on assisted reproductive treatment outcome: a large sample size and well-controlled retrospective study

The effects of maternal cigarette smoking on pregnancy outcomes using assisted reproduction technologies: An updated meta-analysis

There is strong evidence indicating that smoking has negative effects on female reproductive health. Studies to investigate the effects of female smoking on IVF outcomes have been conducted by several research groups, yet the results are controversial. To evaluate the impacts of female smoking on the outcomes of assisted reproduction, a meta-analysis was performed, which included studies published in English up to September 6, 2017 from the MEDLINE, EMBASE, and Cochrane library databases. Twenty-eight studies encompassing 5009 female smokers seeking assisted reproduction and 10,078 non-smokers were used in this meta-analysis. Significant negative outcomes were detected in the female smokers compared with non-smokers including decreases in live birth rate per cycle (OR=0.52, 95% CI 0.37–0.74), in clinical pregnancy rate per cycle (OR 0.59, 95% CI 0.51–0.68), in number of retrieved oocytes (MD=−0.87, 95% CI −1.39 to −0.25), and in average fertilization rate (MD=−4.80, 95% CI −8.49 to −2.02), as well as a significantly increased miscarriage rate per pregnancy (OR=2.48, 95% CI 1.79–3.43). In conclusion, the current meta-analysis provides compelling evidence that female smoking has a significantly negative impact on the outcomes of assisted reproductive technology (ART) and strongly recommends that female smokers will greatly benefit from a smoking cessation before employing ART to become pregnant.

Delayed childbearing and female ageing impair assisted reproductive technology outcome in survivors of male haematological cancers.

To analyse the impact of female characteristics on assisted reproductive technology outcome among male haematological cancer survivors. A retrospective analysis of 93 haematological cancer survivors attending our tertiary referral fertility centre between June 1998 and June 2017 for achieving fatherhood with assisted reproductive technology treatments. A progressive increase in the median female age was observed during the study period (32.2years until the year 2007 and 36.9years from the year 2012). Fifty-five out of 93 patients were treated with intracytoplasmic sperm injection (ICSI) (113 ovarian stimulations, 108 ICSI procedures). Cryopreserved ejaculated sperm was used in 28 couples, fresh sperm in 19, and thawed testicular sperm in 8 couples. Mean female age at ovarian stimulation was 37.0±4.7years. Twenty-six pregnancies resulted in a full-term birth (23% per started ovarian stimulation; 43.6% per couple) and 33 children were born. No significant differences were observed according to source of sperm (fresh, frozen, testicular) and multivariate analysis confirmed that maternal age was the only variable inversely related to the cumulative delivery rate, being five times lower (15.7%) when the female partner was ≥ 40years (OR = 0.22, 95% CI 0.06-0.77) vs. 58.3% with younger women (p = 0.0037). Delayed childbearing and female ageing affect ICSI outcome in couples where the male is a survivor of haematological cancer. This topic should be discussed when counselling male cancer patients about fertility preservation.

Sperm DNA fragmentation index, as measured by sperm chromatin dispersion, might not predict assisted reproductive outcome

ObjectiveRoutine semen parameters have limited clinical diagnostic value for predicting male infertility. The aim of this study was to investigate the association between sperm DNA fragmentation index (DFI) and semen quality, and between DFI and clinical pregnancy rate of in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI). Methods and materialsA total of 390 couples undergoing sperm fragmentation prior to receiving conventional IVF (n = 238) or ICSI (n = 152) were evaluated. ResultsWe found that there were no significant differences in fertilization rate, good embryo rate, or pregnancy rate between high (≥30%) and low (<30%) DFI groups after IVF or ICSI. However, statistically different decreasing motility trends under higher DFI values in the IVF and ICSI groups were detected. Comparison of ROC curve of motility and DFI scores for achieved pregnancy revealed that the best DFI cut-off value was 20%. Also, no significant change was found when 20% DFI level was taken in IVF and ICSI outcomes. ConclusionDFI scores did not provide independent information regarding fertilization, embryo quality, or pregnancy for infertile patients who received IVF or ICSI, but were consistent with semen analysis for infertile couples, regardless of IVF or ICSI outcome.

Outcome of assisted reproductive technology in different subgroups of poor ovarian responders fulfilling the POSEIDON criteria

Abstract Purpose Low success rates are common in women undergoing in vitro fertilization who respond poorly to ovarian hyperstimulation. Due to the heterogeneity of the populations, expressing a unique and shared definition is necessary in order to individualize infertility treatment. The main goal of this study was to evaluate the assisted reproductive technology outcome among various subgroups of poor responders defined by the POSEIDON (Patients-Oriented Strategies Encompassing IndividualizeD Oocyte Number) stratification. Methods In this retrospective cohort study, the clinical and laboratory records of 245 poor responder women undergoing their first ovarian stimulation and fresh embryo transfer cycle were reviewed. Patients were categorized into 4 groups according to the POSEIDON classification. Results The fertilization rate was comparable between groups (p > 0.05). Moreover, there was no difference in implantation rates between groups 1 and 2 and groups 3 and 4 (p > 0.05). In contrast, chemical and clinical pregnancy rates, as well as live birth, were significantly higher in group 1 and 2 compared to the groups 3 and 4 (p 0.05). Conclusions Future studies should explore the most optimal treatment strategy for poor responders according to the POSEIDON stratification and suggested handling with live birth as primary end-point.

Obesity and Outcome of Assisted Reproduction in Patients With Polycystic Ovary Syndrome

Assisted reproduction, including in vitro fertilization and intracytoplasmic sperm injection, is increasingly being used for the management of infertility in patients with polycystic ovary syndrome (PCOS). However, there are limited data regarding the association between obesity and the outcome of assisted reproduction in this specific population as well as on the effects of weight loss. The aim of the present review is to summarize the existing evidence on the association between obesity and the outcome of assisted reproduction in patients with PCOS. Accumulating data suggest that obesity is associated with lower pregnancy and live birth rates in patients with PCOS who are undergoing assisted reproduction therapy. However, it remains unclear whether weight loss improves the outcome of this therapy. Notably, recent guidelines state that the health benefits of postponing pregnancy to achieve weight loss must be balanced against the risk of declining fertility with advancing age. Therefore, if weight loss is not achieved within a reasonable time period, assisted reproduction therapy should be offered in adequately selected patients with PCOS, regardless of the presence of obesity.

Total urokinase-type plasminogen activator (uPA) levels in seminal plasma are associated with positive assisted reproductive technology outcomes.

The plasminogen/plasmin system is an important extracellular protease system whose function has been implicated in male reproductive function. However, its clinical relevance to fertility in human assisted reproduction technologies has not been systematically investigated. Here, we examined whether total and active populations of urokinase-type plasminogen activator (uPA) in human seminal plasma and spermatozoa are predictive of pregnancy outcome in couples undergoing insemination or intracytoplasmic sperm injection (ICSI). Seminal samples from 182 men, 5 donors, 21 patients attending the clinic for infertility screening, and 156 for assisted reproduction technology (ART) treatment (insemination and ICSI), were evaluated. Total uPA in seminal plasma and spermatozoa as well as active uPA in seminal plasma were measured by ELISA. Sperm quality parameters and fertility outcomes following insemination or ICSI were correlated with the uPA values. Active uPA in seminal plasma was positively correlated to the volume of the ejaculate, total number of spermatozoa in the ejaculate, and total motility. However, these values were not prognostic of fertility outcomes. Total uPA in spermatozoa was inversely related to sperm concentration, total sperm in ejaculate, morphology, and total and progressive motility, and this measure was not related to fertility. Importantly, however, higher values of total uPA in seminal plasma were detected in cases that resulted in pregnancy compared to those that did not follow insemination and ICSI treatment. Taken together, these findings lay the foundation for further understanding the mechanism by which total uPA in seminal plasma affects fertility and how this marker can be used as a predictor of ART outcomes.

Relationship between dietary habits and assisted reproduction outcome: A study among infertile Greek women undergoing in-vitro fertilization treatment

Background & aims: Several recent reports have suggested that preconception dietary habits of infertile couples influence assisted reproduction outcome. However, although the role of dietary intake on a macro- and micronutrient level has been extensively studied, only a few studies have focused on the consumption of food groups. The study aimed to investigate whether habitual consumption of specific food groups is related to the successful outcome of an in-vitro fertilization program (IVF), in a sample of infertile women from Greece.

Mimicking physiological O2 tension in the female reproductive tract improves assisted reproduction outcomes in pig.

Is O2 tension in the pig oviduct and uterus affected by the estrous cycle stage and the animal's age, and can the outcome of in vitro embryo development be improved by mimicking these physiological values? O2 tension within the pig reproductive organs is affected by the animal's age, and values close to those measured in vivo have a positive impact on embryo development and quality when used during IVF and embryo culture (EC). To obtain a healthy embryo in vitro, it is necessary to adopt a culture microenvironment that approximates physiological conditions. Despite advances in surgical procedures and sensitive probes that allow accurate assessment of in vivo O2 tension, few such studies have been conducted recently in mammals. In addition, no reference values of physiological O2 tension in the reproductive tract exist for large animal models such as pig, and the effect of O2 tension on ART outcomes is unknown. This study was conducted in pigs. We measured oviductal and uterine O2 tension (n = 29 and 13, respectively) and then examined how the use of the physiological values in pig IVF and EC affected pig ART output (n = 1447 oocytes). The oviductal and uterine O2 tension at the different stages of the estrous cycle was monitored using a laparo-endoscopic single-site surgery (LESS) assisted approach along with a flexible and thin miniaturized luminescent probe. Two groups of pigs, Large-white × Landrace breed, were used: for the first group, 16 pre-pubertal gilts (5 months old and 95 kg) were induced to ovulate with equine chorionic gonadotropin (eCG) and human chorionic gonadotropin (hCG); in the second group 13 mature sows (24-48 months and 185 kg) were used. IVF and EC were performed at two different O2 tensions: Atmospheric O2 (20%) and the mean in vivo value measured (7%). At 18-20 h post-insemination (hpi), a small sample of presumptive zygotes were fixed, stained and examined under epifluorescence microscopy to assess the fertilization rates. At 48 hpi, cleavage was evaluated under the stereomicroscope. Finally, at 180 hpi, development to the blastocyst stage was quantified, blastocyst morphology was assessed, and embryos were fixed and stained to count the mean cell number per blastocyst. The mean O2 content within the pig oviduct and uterus was always lower than in ambient air. The average O2 percentage was higher in gilts (10.0%) than in sows (7.6%) (P < 0.0001). The cleavage rate of porcine in vitro fertilized embryos maintained under 7% O2 during IVF and EC was significantly higher (60.0 ± 2.3) compared with those cultured under 20% O2 (32.0 ± 2.2) (P < 0.05). An increase in the number of cells in embryos cultured under the low O2 concentration (88.9 ± 5.9) was observed compared to those cultured under 20% O2 (59.0 ± 5.0) (P < 0.05). None. Although minimally invasive surgery was used the effect of anesthesia and manipulations on O2 tension within the organs are unknown. Using physiological oxygen concentrations in IVF/EC could improve ART outcomes. This study was funded by Spanish Ministry of Economy and Competitiveness (MINECO) and European Regional Development Fund (FEDER). Grants AGL2012-40180-C03-01 and AGL2015-66341-R. The authors declare no conflict of interest.

Obesity and Male Infertility: Role of Fatty Acids in the Modulation of Sperm Energetic Metabolism

Obesity in men of reproductive age is increasing worldwide, impacting negatively on reproductive potential, sperm function, and assisted reproduction outcomes. Changes in modern eating behaviors are needed to invert the negative correlation between lifestyle and sperm quality. It is known from the literature that fatty acids are able to modulate lipid metabolism by complex mechanisms involving a sequence of interdependent and cross‐regulated molecular events. Although a great deal of data is currently available on the dietary modulation of lipid metabolism, little is known about the nutritional regulation of sperm energetic metabolism. In this review, major data from the literature about the role of some dietary fats as modulators of sperm function and quality are described. Moreover, biochemical mechanisms responsible for an impairment or improvement in sperm bioenergetics are critically analyzed. It is noteworthy that both quantitative and qualitative aspects of dietary fats influence sperm function. The administration of a high‐fat diet, low in polyunsaturated fatty acids, caused a significant increase in body weight hyperglycemia, hyperinsulinemia, and dyslipidemia, along with a significant reduction in sperm quality. In contrast, unsaturated fatty acids are able to positively influence sperm quality and function. The understanding of the biochemical mechanisms underlying the development of male infertility related to obesity led us to depict a possible framework for the molecular action of fatty acids on sperm quality during dysmetabolic conditions.Practical Applications: In this review major data from the literature about the spermatozoa targeting of dietary fatty acids are described and critically analyzed, because now dietary fatty acids are the current focus of research in the field of nutrition and reproduction in males. Such knowledge will eventually translate into the development of new attractive therapeutic approaches for male infertility related to alterations in lipid metabolism.Dietary fatty acids are involved in the nutritional modulation of sperm energetic metabolism. Diets rich in saturated fatty acids (SFA) and low in polyunsaturated fatty acids (PUFA) seem to correlate with defective sperm energy metabolism and reduced sperm quality. Administration of PUFA, especially n‐3 PUFA, determines an increase in sperm concentration, and motility, associated to an increase in the activities of mitochondrial enzymes involved in gamete energetic metabolism and to a reduction in oxidative damaeg

Re: Outcome of assisted reproduction in women with congenital uterine anomalies: a prospective observational study. M. Prior, A. Richardson, S. Asif, L. Polanski, M. Parris-Larkin, J. Chandler, L. Fogg, P. Jassal, J. G. Thornton, N. J. Raine-Fenning. Ultrasound Obstet Gynecol 2018; 51: 110-117.

Linked Comment: Ultrasound Obstet Gynecol 2018; 51: 110–117

Outcome of assisted reproduction in women with congenital uterine anomalies: a prospective observational study.

To assess the prevalence of congenital uterine anomalies, including arcuate uterus, and their effect on reproductive outcome in subfertile women undergoing assisted reproduction. Consecutive women referred for subfertility between May 2009 and November 2015 who underwent assisted reproduction were included in the study. As part of the initial assessment, each woman underwent three-dimensional transvaginal sonography. Uterine morphology was classified using the modified American Fertility Society (AFS) classification of congenital uterine anomalies proposed by Salim et al. If the external contour of the uterus was uniformly convex or had an indentation of < 10 mm, but there was a cavity indentation, it was defined as arcuate or septate. Arcuate uterus was further defined as the presence of a concave fundal indentation with a central point of indentation at an obtuse angle. Subseptate uterus was defined as the presence of a septum, not extending to the cervix, with the central point of the septum at an acute angle; if the septum extended to the internal cervical os, the uterus was defined as septate. Reproductive outcomes, including live birth, clinical pregnancy and preterm birth, were compared between women with a normal uterus and those with a congenital uterine anomaly. Subgroup analysis by type of uterine morphology and logistic regression analysis adjusted for age, body mass index, levels of anti-Müllerian hormone, antral follicle count and number and day of embryo transfer were performed. A total of 2375 women were included in the study, of whom 1943 (81.8%) had a normal uterus and 432 (18.2%) had a congenital uterine anomaly. The most common anomalies were arcuate (n = 387 (16.3%)) and subseptate (n = 16 (0.7%)) uterus. The rate of live birth was similar between women with a uterine anomaly and those with a normal uterus (35% vs 37%; P = 0.47). The rates of clinical pregnancy, mode of delivery and sex of the newborn were also similar between the two groups. Preterm birth before 37 weeks' gestation was more common in women with uterine anomalies than in controls (22% vs 14%, respectively; P = 0.03). Subgroup analysis by type of anomaly showed no difference in the incidence of live birth and clinical pregnancy for women with an arcuate uterus, but indicated worse pregnancy outcome in women with other major anomalies (P = 0.042 and 0.048, respectively). Congenital uterine anomalies as a whole, when defined using the modified AFS classification, do not affect clinical pregnancy or live-birth rates in women following assisted reproduction, but do increase the incidence of preterm birth. The presence of uterine abnormalities more severe than arcuate uterus significantly worsens all pregnancy outcomes. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Effect of the endometriomas on ovarian stimulation and pregnancy rate on assisted reproductive outcomes

Endometriosis is a disease known to be detrimental to fertility. Women with endometriosis, and the presence of endometrioma, may require assisted reproductive technologies to achieve a pregnancy. Aim: Our aim was to evaluate the effect of endometriosis and the presence of an endometrioma on outcomes of conventional in vitro fertilization/intra-cytoplasmic sperm injection (ICSI). Materials and Methods: The study group consisted of 45 infertile women with either unilateral or bilateral ovarian endometrial cysts of less than 3 cm. The control group consisting of 50 patients with mild male factor infertility was candidate for ICSI treatment during the same time period as the study groups. Both groups were compared for number of oocytes retrieved, grades of oocytes, as well as embryo quantity and quality. Results: Our findings showed similar follicle numbers, good embryo grades (I or II) and pregnancy rates in the compared groups. However, patients with endometriosis had higher gonadotropin consumption than the control group. The mean number of retrieved oocytes in patients with endometriosis was significantly lower than control group (P < 0.0001). The numbers of metaphase II (MII) oocytes were significantly lower in patients with endometriosis as compared to the control group 6.11 ± 2.92 vs. 9.32 ± 4.71, respectively (P = 0.0002). In patients with unilateral endometriosis, there were significant differences in terms of fertilization rate, retrieved oocyte and MII oocyte between the normal and involved ovaries; P < 0.5. Conclusion: The endometriomas group had a significantly poorer ovarian response and required significantly more ampoules of follicle-stimulating hormone per cycle. They showed poor ovarian response with lower total numbers of retrieved oocytes and lower MII oocytes during the stimulation phase; however, it does not affect the quality of embryos and pregnancy rate per patient.

Is there an association between artificial sweetener consumption and assisted reproduction outcomes?

Previous studies have suggested an association between high intake of sweetened beverages and a number of adverse health outcomes. In this cross-sectional study, we investigated the association between daily consumption of sweetened soft drinks or coffee and the outcome of intracytoplasmic sperm injection (ICSI) treatment. Patients (n = 524) were interviewed by a nutritionist before ICSI treatment, using a food frequency questionnaire. Regression analysis showed that consumption of ≥3 servings of regular soft drinks or any amount of diet soft drinks was associated with oocyte dysmorphism, diminished embryo quality on days 2 and 3 of culture, and a mild effect on blastocyst formation, implantation and pregnancy rate. Consumption of artificially sweetened coffee was negatively associated with embryo quality on days 2 and 3. However, consumption of coffee or soft drinks was not associated with the odds of live birth. Even so, patients should be advised about the potential negative effects of sugar and artificial sweeteners before attempting infertility treatment. This study is limited by the use of a non-validated food frequency questionnaire, lack of information on quantity of sweeteners consumed, and lack of data on glucose levels in blood serum or follicular fluid. Further investigation is warranted.

Commentary on sperm DNA fragmentation testing clinical guideline.

The study of physiology of reproduction, particularly in mammalian species, experienced glorious times in the second half of the twentieth century. However, with the advent of intracytoplasmic sperm injection (ICSI), the decade of 1990 appeared to forecast the demise of translational research in male reproductive biology. In fact, in its original and subsequent work, Palermo and colleagues showed that ICSI bypassed the process of natural selection of sperm (1). Then, the prevailing hope became that the only need would be merely to obtain one acceptable spermatozoon. The optimism, based on an exponential increase of successful results, has been moderated in the last decade by results indicating that certain sperm characteristics have an impact on the outcomes of assisted reproduction (2). Recent basic research findings have radically transformed our understanding of the biology of fertilization (3), underscoring the importance of cytological processes, e.g. the timing of sperm acrosomal exocytosis (4), in addition to sperm-associated epigenetic factors (5), proteomics (6) and DNA structure (7,8).