Mitochondria in Human Fertility and Infertility.

In human spermatozoa and oocytes (and their surrounding granulosa cells), mitochondria carry out important functions relating to human fertility and infertility. Sperm mitochondria are not transmitted to the future embryo, but are closely related to the generation of energy needed for sperm movement, capacitation, and acrosome reactions, as well as for sperm-oocyte fusion. On the other hand, oocyte mitochondria produce energy required for oocyte meiotic division and their abnormalities can thus cause oocyte and embryo aneuploidy. In addition, they play a role in oocyte calcium metabolism and in essential epigenetic events during the oocyte-to-embryo transition. They are transmitted to the future embryos and may thus cause hereditary diseases in the offspring. Due to the long life span of the female germ cells, the accumulation of mitochondrial DNA abnormalities often causes ovarian aging. Mitochondrial substitution therapy is the only way of dealing with these issues nowadays. New therapies based on mitochondrial DNA editing are under investigation.

Cyclic Adenosine Monophosphate: A Central Player in Gamete Development and Fertilization, and Possible Target for Infertility Therapies.

Human infertility, of both male and female origin, is often caused by the deficient response of the testis and the ovary to hormonal stimuli that govern sperm and oocyte development and fertilization. The effects of hormones and other extracellular ligands involved in these events are often mediated by G-protein-coupled receptors that employ cyclic adenosine monophosphate (cAMP) as the principal second messenger transducing the receptor-generated signal to downstream elements. This opinion article summarizes the actions of cAMP in sperm and oocyte development and fertilization, leading to therapeutic actions targeting cAMP metabolism to alleviate human male and female infertility.

Patient-tailored reproductive health care.

Patient-tailored reproductive health care represents an important challenge for the current practice of infertility prevention, diagnosis and treatment. This approach is based on the concept of precision medicine, taking into account genetic, epigenetic, metabolic and lifestyle characteristics of each individual patient. Even though this goal is still far from being wholly achieved, some aspects can already be put into practice nowadays. Personalization can be based on a comprehensive analysis and synthesis of the patients' personal and familial history, taking into account outcomes of previous assisted reproduction technique (ART) attempts, if available, and confronting these data with the past and the latest clinical and laboratory examination outcomes. As to the male fertility status, there is an urgent need for the inclusion of an accurate diagnostic workup of infertile men leading to the choice of the most adequate follow-up for each particular pathological condition. The follow-up of women who have become pregnant as a result of the ART attempt has also to be personalized. This should be done taking into account both the basic data extracted from the patient's file and those derived from the experience gathered during the latest attempt. Last but not least, the individual condition of each couple has to be taken into account when counseling the patients as to the urgency of the actions to be taken to resolve their fertility problem.

Molecular Clues to Understanding Causes of Human-Assisted Reproduction Treatment Failures and Possible Treatment Options.

More than forty years after the first birth following in vitro fertilization (IVF), the success rates of IVF and of IVF-derived assisted reproduction techniques (ART) still remain relatively low. Interindividual differences between infertile couples and the nature of the problems underlying their infertility appear to be underestimated nowadays. Consequently, the molecular basis of each couple's reproductive function and of its disturbances is needed to offer an individualized diagnostic and therapeutic approaches to each couple, instead of applying a standard or minimally adapted protocols to everybody. Interindividual differences include sperm and oocyte function and health status, early (preimplantation) embryonic development, the optimal window of uterine receptivity for the implanting embryo, the function of the corpus luteum as the main source of progesterone production during the first days of pregnancy, the timing of the subsequent luteoplacental shift in progesterone production, and aberrant reactions of the uterine immune cells to the implanting and recently implanted embryos. In this article, the molecular basis that underlies each of these abnormalities is reviewed and discussed, with the aim to design specific treatment options to be used for each of them.

Use of pentoxifylline during ovarian stimulation to improve oocyte and embryo quality: A retrospective study.

OBJECTIVE: This study aims to investigate if the administration of pentoxifylline during ovarian stimulation have an impact on the quantity and quality of oocytes recovered for in vitro fertilization (IVF), the quality of zygotes and embryos resulting from IVF, the serum estradiol and progesterone concentrations, the endometrial thickness and pregnancy outcomes after embryo transfer. METHODS: Retrospective crossover study including 18 women with recurrent implantation failur, defined as having a history of at least two consecutive cycles of implantation failure and 25-45 years of age at the time of embryo transfer. Pentoxifylline was added during their following IVF attempt aiming to improve endometrial function. Oocyte, zygote and embryo quality, serum estradiol and progesterone concentrations, endometrial thickness and IVF outcomes were compared between the two sequential attempts. RESULTS: Compared to the first attempt, the outcomes of the second attempt, with the addition of pentoxifylline administration, resulted in higher numbers of total and mature oocytes, better oocyte, zygote and embryo quality, higher serum estradiol concentrations, thicker endometrium and better clinical IVF outcomes. CONCLUSIONS: The administration of pentoxifylline during ovarian stimulation seems to improve IVF outcomes, not only by the generating a thicker endometrial lining, but also by producing a higher number of oocytes, with better oocyte, zygote and embryo quality, and higher serum estradiol concentrations.

Double HCG trigger improves recovery of oocytes in women with a paucifollicular response to ovarian stimulation: A pilot study.

OBJECTIVE: To examine whether adding a second HCG trigger, 12.5 h after the first (36.5 h before ovarian puncture), can facilitate recovery of oocytes in women with a paucifollicular response to ovarian stimulation. METHODS: A total of 85 women aged 35-42 years, with a paucifollicular response to ovarian stimulation and who had experienced a total failure of oocyte recovery after the standard HCG ovulation trigger 36.5 h before ovarian puncture, were subsequently treated by the same protocol but with the addition of a second HCG trigger 12.5 h later. The recovered oocytes were inseminated by intracytoplasmic sperm injection (ICSI) and all available embryos were transferred 3 days later. RESULTS: The double trigger enabled recovery of cumulus oophorus cells from most of the follicles in the women who experienced failure of total recovery of oocytes after a single trigger. Fifteen patients became pregnant, and no signs of ovarian hyperstimulation syndrome were observed. Nine women delivered a healthy child. CONCLUSION: In women aged 35-42 years with a paucifollicular response to ovarian stimulation, a double HCG trigger appears to improve the rate of oocyte recovery. The conclusion of this pilot study needs to be confirmed by larger prospective trials.

Assessing the testicular sperm microbiome: a low-biomass site with abundant contamination.

RESEARCH QUESTION: The semen harbours a diverse range of microorganisms. The origin of the seminal microbes, however, has not yet been established. Do testicular spermatozoa harbour microbes and could they potentially contribute to the seminal microbiome composition? DESIGN: The study included 24 samples, comprising a total of 307 testicular maturing spermatozoa. A high-throughput sequencing method targeting V3 and V4 regions of 16S rRNA gene was applied. A series of negative controls together with stringent in-silico decontamination methods were analysed. RESULTS: Between 50 and 70% of all the detected bacterial reads accounted for contamination in the testicular sperm samples. After stringent decontamination, Blautia (P = 0.04), Cellulosibacter (P = 0.02), Clostridium XIVa (P = 0.01), Clostridium XIVb (P = 0.04), Clostridium XVIII (P = 0.02), Collinsella (P = 0.005), Prevotella (P = 0.04), Prolixibacter (P = 0.02), Robinsoniella (P = 0.04), and Wandonia (P = 0.04) genera demonstrated statistically significant abundance among immature spermatozoa. CONCLUSIONS: Our results indicate that the human testicle harbours potential bacterial signature, though in a low-biomass, and could contribute to the seminal microbiome composition. Further, applying stringent decontamination methods is crucial for analysing microbiome in low-biomass site.

Ovarian Aging: Molecular Mechanisms and Medical Management.

This is a short review of the basic molecular mechanisms of ovarian aging, written with a particular focus on the use of this data to improve the diagnostic and therapeutic protocols both for women affected by physiological (age-related) ovarian decay and for those suffering premature ovarian insufficiency. Ovarian aging has a genetic basis that conditions the ovarian activity via a plethora of cell-signaling pathways that control the functions of different types of cells in the ovary. There are various factors that can influence these pathways so as to reduce their efficiency. Oxidative stress, often related to mitochondrial dysfunction, leading to the apoptosis of ovarian cells, can be at the origin of vicious circles in which the primary cause feeds back other abnormalities, resulting in an overall decline in the ovarian activity and in the quantity and quality of oocytes. The correct diagnosis of the molecular mechanisms involved in ovarian aging can serve to design treatment strategies that can slow down ovarian decay and increase the quantity and quality of oocytes that can be obtained for an in vitro fertilization attempt. The available treatment options include the use of antioxidants, melatonin, growth hormones, and mitochondrial therapies. All of these treatments have to be considered in the context of each couple's history and current clinical condition, and a customized (patient-tailored) treatment protocol is to be elaborated.

Human artificial oocytes from patients' somatic cells: past, present and future.

The first attempts at generating functional human oocytes by using the transfer of patients' somatic cell nuclei, as DNA source, into donor enucleated oocytes date back to the early 2000s. After initial attempts, that gave rather encouraging results, the technique was abandoned because of adverse results with this technique in the mouse model. Priority was then given to the use of induced pluripotent stem (iPS) cells, based on excellent results in the mouse, where mature oocytes and live healthy offspring were achieved. However, these results could not be reproduced in humans, and oogenesis with human iPS cells did not continue beyond the stage of oogonium. These data suggest that the use of enucleated donor oocytes will be necessary to achieve fertilizable human oocytes with somatic cell-derived DNA. The main problem of all these techniques is that they have to meet with two, sometimes contradictory, requirements: the haploidization of somatic cell-derived DNA, on the one hand, and the remodeling/reprogramming of DNA of somatic cell origin, so as to be capable of supporting all stages of preimplantation and postimplantation development and to give rise to all cell types of the future organism. Further research is needed to determine the optimal strategy to cope with these two requirements. LAY SUMMARY: The recourse to artificial oocytes, generated by using the patient's own DNA derived from cells of somatic origin, represents the ultimate opportunity for women who lack healthy oocytes of their own but yearn for genetically related offspring. Many different pathologies, such as ovarian cancer, premature ovarian failure, other ovarian diseases and natural, age-related ovarian decay can cause the absence of available oocytes. The demand for artificial oocytes is increasing continuously, mainly because of the tendency to postpone maternity to still more advanced ages, when the quantity and quality of oocytes is low. This minireview focuses on the generation of artificial oocytes using different strategies and scenarios, based on the accumulated experience in humans and experimental animals.

The Effect of GH Administration on Oocyte and Zygote Quality in Young Women With Repeated Implantation Failure After IVF.

Growth hormone (GH) has been shown to improve implantation and live birth rates in women of >40 years of age treated by in vitro fertilization (IVF). This effect was initially attributed to a GH effect on oocyte quality, but later studies showed that GH can also improve uterine receptivity for embryo implantation. As to younger women with previous failures of embryo implantation after IVF, data reported in the literature are ambiguous. This retrospective study focused on this latter category of women, comparing the numbers and morphological appearance of oocytes recovered from women with two previous IVF failures, aged between 30 and 39 years and treated with GH, with a comparable group of women without GH treatment. These results were complemented with the analysis of morphological markers of zygote and embryo quality and IVF clinical outcomes in both groups. The oocytes, zygotes and embryos from women treated with GH showed better morphological scores, and their uterine transfer resulted in more implantations, pregnancies and live births, as compared with the untreated group. It is concluded that the improvement of IVF outcomes in women with previous repeated IVF failures by exogenous GH administration is, at least partly, related to an increase in oocyte developmental potential. The statistically evident improvement of oocyte and embryo quality is the main finding of this study. Its weakness is its retrospective nature.

Luteal Phase in Assisted Reproductive Technology.

Luteal phase (LP) is the period of time beginning shortly after ovulation and ending either with luteolysis, shortly before menstrual bleeding, or with the establishment of pregnancy. During the LP, the corpus luteum (CL) secretes progesterone and some other hormones that are essential to prepare the uterus for implantation and further development of the embryo, the function known as uterine receptivity. LP deficiency (LPD) can occur when the secretory activity of the CL is deficient, but also in cases of normal CL function, where it is caused by a defective endometrial response to normal levels of progesterone. LPD is particularly frequent in treatments using assisted reproductive technology (ART). Controlled ovarian stimulation usually aims to obtain the highest number possible of good-quality oocytes and requires the use of gonadotropin-releasing hormone (GnRH) analogs, to prevent premature ovulation, as well as an ovulation trigger to achieve timed final oocyte maturation. Altogether, these treatments suppress pituitary secretion of luteinizing hormone (LH), required for the formation and early activity of the CL. In addition to problems of endometrial receptivity for embryos, LPD also leads to dysfunction of the local uterine immune system, with an increased risk of embryo rejection, abnormally high uterine contractility, and restriction of uterine blood flow. There are two alternatives of LPD prevention: a direct administration of exogenous progesterone to restore the physiological progesterone serum concentration independently of the CL function, on the one hand, and treatments aimed to stimulate the CL activity so as to increase endogenous progesterone production, on the other hand. In case of pregnancy, some kind of LP support is often needed until the luteal-placental shift occurs. If LPD is caused by defective response of the endometrium and uterine immune cells to normal concentrations of progesterone, a still poorly defined condition, symptomatic treatments are the only available solution currently available.

High dose of d-chiro-inositol improves oocyte quality in women with polycystic ovary syndrome undergoing ICSI: a randomized controlled trial.

The aim of this study was to evaluate the effect of two doses of d-chiro-inositol (DCI) in combination with Myo-inositol (MYO) on the oocyte quality (OQ) of women with polycystic ovarian syndrome (PCOS) undergoing intracytoplasmic sperm injection (ICSI). Methods: This was a controlled, randomized, double-blind, parallel group study on 172 oocytes from 11 women. The study compared the effect of two MYO-DCI formulations given over 12 weeks on OQ. Five women received 550 mg of MYO + 300 mg of DCI daily (high DCI content group), while 6 women were given a daily dose of 550 mg of MYO with the only 27.6 mg of DCI (low DCI content group). Results: According to a multivariate analysis using linear mixed effect models, high doses of DCI have a positive influence on the quality of the cytoplasm of the oocyte (ß = 1.631, χ2 = 7.347, d.f. = 1, p = .00672). Zona pellucida, plasma membrane, cytoplasm, and sperm reception have also been improved with any combination of MYO/DCI by decreasing testosterone or improving insulin sensitivity, regardless of age and body mass index. Conclusion: The combination of MYO with high doses of DCI improved oocyte cytoplasm quality in women with PCOS undergoing ICSI.

GnRH agonist treatment of luteal phase deficiency in HCG-triggered IVF cycles: a matched case-control study.

RESEARCH QUESTION: This study aimed to identify women with IVF failure associated with low serum progesterone levels after embryo transfer in HCG-triggered cycles and to evaluate the effects of gonadotrophin-releasing hormone (GnRH) agonist, administered after embryo transfer, on serum progesterone and pregnancy outcomes in these cases. DESIGN: Fifty women who failed to achieve an ongoing clinical pregnancy and had abnormally low luteal-phase serum progesterone concentrations in their first IVF attempt were assigned to two matched groups in their subsequent attempt. Twenty-five women were treated with the original protocol plus14 daily injections of GnRH agonist, beginning on the day of oocyte recovery, in their second IVF attempt (group 1). These women were matched to 25 women with the same characteristics and outcomes in their first IVF attempt who underwent the second IVF attempt without the use of GnRH agonist after embryo transfer (group 2). In both groups, the two sequential attempts were compared for serum progesterone concentration 14 days after oocyte recovery and pregnancy outcome. RESULTS: The patients in group 1 had significantly higher progesterone levels 14 days after oocyte recovery in the second attempt compared with the first attempt (P < 0.001), and 12 (48%) of them achieved clinical pregnancy and birth. No significant differences in pregnancy outcome or in the serum progesterone concentration were observed between the first and the second attempt in group 2. CONCLUSIONS: In patients with luteal phase deficiency, the administration of GnRH agonist after embryo transfer increases serum progesterone concentration and improves the chance of pregnancy and birth.

Comparison of the effect of two combinations of myo-inositol and D-chiro-inositol in women with polycystic ovary syndrome undergoing ICSI: a randomized controlled trial.

The purpose of this study was to evaluate the effect of two doses of D-chiro-inositol (DCI) in combination with Myo-inositol (MYO) in women with PCOS undergoing ICSI. This was a multicenter controlled, randomized, double-blind parallel group study with two MYO-DCI formulations for 12 weeks. The study group (SG) was administered 550 mg of MYO + 150 mg of DCI twice daily; the control group (CG) was administered 550 mg of MYO + 13.8 mg of DCI twice daily. The participants comprised 60 women with PCOS undergoing ICSI. At baseline, no differences were found between the two groups regarding age, BMI, HOMA-IR or testosterone levels. The pregnancy and live birth rates were significantly higher in the SG than in the CG (65.5 vs. 25.9 and 55.2 vs. 14.8, respectively) [risk ratio (RR) = 0.4; 95%CI (0.2, 0.79); p = .003 and RR = 0.27; 95%CI (0.10, 0.70); p = .002 respectively]. The risk of ovarian hyperstimulation syndrome (OHSS) was lower in the SG (3.44 vs. 18.5%, p = .07). The combination of MYO-DCI at high doses of DCI improves the pregnancy rates and reduces the risk of OHSS in women with PCOS undergoing ICSI.

Effect of Growth Hormone on Uterine Receptivity in Women With Repeated Implantation Failure in an Oocyte Donation Program: A Randomized Controlled Trial.

BACKGROUND AND OBJECTIVE: Administration of growth hormone (GH) during ovarian stimulation has been shown to improve success rates of in vitro fertilization. GH beneficial effect on oocyte quality is shown in several studies, but GH effect on uterine receptivity is not clear. To assess it, we studied whether GH administration can improve the chance of pregnancy and birth in women who experienced repeated implantation failure (RIF) using donated oocyte programs. DESIGN AND STUDY POPULATION: A total of 105 infertile women were enrolled in the randomized controlled trial: 70 women were with a history of RIF with donated oocytes, and 35 infertile women underwent the first oocyte donation attempt. Women receiving donated oocytes were treated with progressively increasing doses of oral estradiol, followed by intravaginal progesterone after previous pituitary desensitization with gonadotropin-releasing hormone agonist. Thirty-five RIF patients were treated with GH (GH patients), whereas the rest of the 35 RIF patients (non-GH patients) and 35 first-attempt patients (positive control group) were not. RESULTS: RIF patients receiving GH showed significantly thicker endometrium and higher pregnancy and live birth rates as compared with RIF patients of non-GH study group, although these rates remained somewhat lower as compared with the non-RIF patients of the positive control group. No abnormality was detected in any of the babies born. CONCLUSION: Our data of improved implantation, pregnancy, and live birth rates among infertile RIF patients treated with GH indicate that GH improves uterine receptivity.