A correlation of the outcome of clinical in vitro fertilization with the inositol content and embryotrophic properties of human serum

The role of myo-inositol supplement in assisted reproductive techniques

Assisted reproductive techniques can help many infertile couples conceive. Therefore, there is a need for an effective method to overcome the widespread problems of infertile men and women. Oocyte and sperm quality can increase the chances of successful in vitro fertilisation. The maturation environment in which gametes are present can affect their competency for fertilisation. It is well established that myo-inositol (MI) plays a pivotal role in reproductive physiology. It participates in cell membrane formation, lipid synthesis, cell proliferation, cardiac regulation, metabolic alterations, and fertility. This molecule also acts as a direct messenger of insulin and improves glucose uptake in various reproductive tissues. Evidence suggests that MI regulates events such as gamete maturation, fertilisation, and embryo growth through intracellular Ca2 + release and various signalling pathways. In addition to the in-vivo production of MI from glucose in the reproductive organs, its synthesis by in vitro-cultured sperm and follicles has also been reported. Therefore, MI is suggested as a therapeutic approach to maintain sperm and oocyte health in men and women with reproductive disorders and individuals of reproductive age.

Polycystic ovarian syndrome-current pharmacotherapy and clinical implications

Polycystic ovary syndrome (PCOS), the most common endocrinopathy in women is characterized by polycystic ovaries, chronic anovulation and hyperandrogenism. The treatment in PCOS is mainly symptomatic and involves lifestyle interventions and medications such as Metformin, Oral contraceptives and Antiandrogens. However, the management of PCOS is challenging and current interventions are not able to deal with outcomes of this syndrome. This review encompasses latest pharmacotherapeutic and non-pharmacotherapeutic interventions currently in use to tackle various symptomatic contentions in PCOS. Our focus has been mainly on novel therapeutic modalities for treatment/management of PCOS, like use of newer insulin sensitizers viz., Inositols, Glucagon-like peptide-1(GLP-1) agonists, Dipeptidyl pepdidase-4 (DPP-4) inhibitors, and sodium-glucose transport protein 2 (SGLT2) inhibitors. Also, evidence suggesting the use of vitamin D, statins, and Letrozole as emerging therapies in PCOS have been summarized in this review. Additionally, novel cosmetic techniques like electrolysis, laser and use of topically applied eflornithine to tackle the most distressing feature of facial hirsutism associated with PCOS, non-pharmacological therapy like acupuncture and the role of herbal medicine in PCOS management have also been discussed.

Inositols: From Established Knowledge to Novel Approaches

Myo-inositol (myo-Ins) and D-chiro-inositol (D-chiro-Ins) are natural compounds involved in many biological pathways. Since the discovery of their involvement in endocrine signal transduction, myo-Ins and D-chiro-Ins supplementation has contributed to clinical approaches in ameliorating many gynecological and endocrinological diseases. Currently both myo-Ins and D-chiro-Ins are well-tolerated, effective alternative candidates to the classical insulin sensitizers, and are useful treatments in preventing and treating metabolic and reproductive disorders such as polycystic ovary syndrome (PCOS), gestational diabetes mellitus (GDM), and male fertility disturbances, like sperm abnormalities. Moreover, besides metabolic activity, myo-Ins and D-chiro-Ins deeply influence steroidogenesis, regulating the pools of androgens and estrogens, likely in opposite ways. Given the complexity of inositol-related mechanisms of action, many of their beneficial effects are still under scrutiny. Therefore, continuing research aims to discover new emerging roles and mechanisms that can allow clinicians to tailor inositol therapy and to use it in other medical areas, hitherto unexplored. The present paper outlines the established evidence on inositols and updates on recent research, namely concerning D-chiro-Ins involvement into steroidogenesis. In particular, D-chiro-Ins mediates insulin-induced testosterone biosynthesis from ovarian thecal cells and directly affects synthesis of estrogens by modulating the expression of the aromatase enzyme. Ovaries, as well as other organs and tissues, are characterized by a specific ratio of myo-Ins to D-chiro-Ins, which ensures their healthy state and proper functionality. Altered inositol ratios may account for pathological conditions, causing an imbalance in sex hormones. Such situations usually occur in association with medical conditions, such as PCOS, or as a consequence of some pharmacological treatments. Based on the physiological role of inositols and the pathological implications of altered myo-Ins to D-chiro-Ins ratios, inositol therapy may be designed with two different aims: (1) restoring the inositol physiological ratio; (2) altering the ratio in a controlled way to achieve specific effects.

Grading of endometrial cancer using 1H HR-MAS NMR-based metabolomics

The tissue metabolomic characteristics associated with endometrial cancer (EC) at different grades were studied using high resolution (400 MHz) magic angle spinning (HR-MAS) proton spectroscopy. The metabolic profiles were obtained from 64 patients (14 with grade 1 (G1), 33 with grade 2 (G2) and 17 with grade 3 (G3) tumors) and compared with the profile acquired from 10 patients with the benign disorders. OPLS-DA revealed increased valine, isoleucine, leucine, hypotaurine, serine, lysine, ethanolamine, choline and decreased creatine, creatinine, glutathione, ascorbate, glutamate, phosphoethanolamine and scyllo-inositol in all EC grades in reference to the non-transformed tissue. The increased levels of taurine was additionally detected in the G1 and G2 tumors in comparison to the control tissue, while the elevated glycine, N-acetyl compound and lactate—in the G1 and G3 tumors. The metabolic features typical for the G1 tumors are the increased dimethyl sulfone, phosphocholine, and decreased glycerophosphocholine and glutamine levels, while the decreased myo-inositol level is characteristic for the G2 and G3 tumors. The elevated 3-hydroxybutyrate, alanine and betaine levels were observed in the G3 tumors. The differences between the grade G1 and G3 malignances were mainly related to the perturbations of phosphoethanolamine and phosphocholine biosynthesis, inositol, betaine, serine and glycine metabolism. The statistical significance of the OPLS-DA modeling was also verified by an univariate analysis. HR-MAS NMR based metabolomics provides an useful insight into the metabolic reprogramming in endometrial cancer.

An innovative approach to polycystic ovary syndrome

Myo-inositol and D-chiro-inositol are insulin sensitising agents. In the ovary, myo-inositol acts as second messenger of Follicle Stimulating Hormone (FSH). Both molecules were administered to Polycystic Ovary Syndrome (PCOS) women. The gynaecologist Vittorio Unfer was the first to give specific value to myo-inositol for the treatment of PCOS: this important innovation opened new ways of research to identify efficient therapies based on myo-inositol alone or with low doses of D-chiro-inositol. Significant successes were also gained using myo-inositol in treating male and female infertility. Unfer's researches allowed to identify "the D-Chiro-Inositol Paradox in the Ovary" and the best myo-inositol/D-chiro-inositol ratio (40:1) for the treatment of PCOS. Furthermore, his studies allowed to improve the inositol's efficacy using alpha-lactalbumin. As shown in this review, the main stages of Unfer's scientific career have been closely intertwined with important phases of the recent pharmacological research about the topic.

Myo-Inositol as a Key Supporter of Fertility and Physiological Gestation

Pregnancy is a complex process, featuring several necessary changes in women’s physiology. Most women undergo healthy pregnancies; even so, several women experience reduced fertility or pathologies related to the pregnancy. In the last years, researchers investigated several molecules as promoters of fertility. Among all, myo-inositol (myo-ins) represents a safe compound that proved useful in issues related to fertility and pregnancy. In fact, myo-ins participates in several signaling processes, including the pathways of insulin and gonadotropins, and, therefore, it is likely to positively affect fertility. In particular, several clinical trials demonstrate that its administration can have therapeutic effects in infertile women, and that it can also be useful as a preventive treatment during pregnancy. Particularly, myo-ins could prevent the onset of neural tube defects and the occurrence of gestational diabetes mellitus, promoting a trouble-free gestation. Due to the safety and efficiency of myo-ins, such a treatment may also substitute several pharmaceuticals, which are contraindicated in pregnancy.

The effect of Myo-inositol on fertility rates in poor ovarian responder in women undergoing assisted reproductive technique: a randomized clinical trial

BACKGROUND

Poor ovarian response to gonadotropin is a significant challenge in assisted reproductive technique (ART) and affect 9-24% of ART cycles. This study aimed to evaluate the effect of Myo-inositol on fertility rates in poor ovarian responder women undergoing assisted reproductive technique.

METHODS

This study is a double-blinded randomized controlled study that involved 60 poor ovarian responders included in an ICSI program and divided into two groups; intervention group: 30 patients who have been assuming Inofolic (4 g myo-inositol + 400 μg folic acid) for the before the enrollment day; control group: 30 patients assuming folic acid (400 μg) for the same period. Controlled ovarian stimulation was performed in the same manner in the two groups. The main outcomeswere the assessment of oocytes retrievednumber and quality, ovarian sensitivity index,required dose of Gonadotropinsunits × 1000), fertilization rate, biochemical, and clinical pregnancy rate.

RESULT

There is no significant difference in clinical characteristics between study groups. The number of oocytes retrieved, number of MII oocytes, number of embryos transferred, chemical, and clinical pregnancy were higher in the intervention group. However, they are not statistically significant in comparison to the control group. The ovarian sensitivity index and fertilization rate were significantly higher in the intervention group than the control group (P > 0.05). The required dose of gonadotropin significantly lower in the intervention group than the control group.

CONCLUSION

Our results suggest that the supplementation myo-inositol in poor ovarian responders significantly improved the ART outcomes such as fertilization rate gonadotropin, ovarian sensitivity index (OSI) and significantly reduced the required unities of gonadotropin. Additionally, more extensive randomized controlled studies are needed.

TRIAL REGISTRATION

Iranian Registry of Clinical Trials, IRCT20180515039668N1 , retrospectively registered since 2020-03-16.

The efficacy of different insulin-sensitizing agents on treatment outcomes in patients with polycystic ovary syndrome who underwent in-vitro fertilization: A retrospective, record-based, comparative study

INTRODUCTION

It is not clear which metformin or inositol is more effective on IVF results. The aim of this study was to compare the effects of Metformin and Inositol co-treatments on IVF outcomes in Polycystic ovary syndrome patients.

METHODS

A retrospective examination was made of the demographic characteristics and the follicular-embryonic development results of PCOS patients applied with an antagonist protocol of ovarian hyperstimulation in the first cycle of IVF with co-treatment of Metformin at 2000 mg/day regularly for 3 months (Metformin co-treatment group, n:35) or Inositol at 4000 mg/day myo-inositol for 3 months (Inositol co-treatment group, n:34) and those not using any co-treatment (FSH only group [control group], n:40).

RESULTS

No significant difference was determined between the groups in respect of demographic characteristics. The HOMA-IR scores and hCG day E2 level were significantly higher in the control group than in both co-treatment groups (p = 0.021, p = 0.018, respectively). The M1 oocyte count was significantly lower in the Metformin group than in the Inositol and control groups (p = 0.001). The GVDJ oocyte count was significantly lower in both co-treatment groups than in the control group (p = 0.042). No statistically significant difference was determined between the groups in respect of other follicular and embryological development parameters, implantation, clinical pregnancy, live births and abortus rates.

CONCLUSION

Insulin-sensitizing agents may have positive effects on follicular development in PCOS patients applied with IVF.

Breakthroughs in the Use of Inositols for Assisted Reproductive Treatment (ART)

It is well known that myo-inositol (MI) and D-chiro-inositol (DCI) are insulin-sensitizing agents, and MI is of proven utility in polycystic ovary syndrome (PCOS). In addition, MI plays a pivotal role in the physiology of reproduction, and has beneficial effects on the development of oocytes, spermatozoa, and embryos. By contrast, DCI has little effect on spermatozoa, but high concentrations in the ovary can negatively affect the quality of oocytes and the blastocyst. Overall, the evidence in the literature supports the beneficial effects of MI in both female and male reproduction, warranting clinical use of MI in assisted reproductive treatment (ART).

Inositol Treatment for PCOS Should Be Science-Based and Not Arbitrary

The aim of this paper is to critically analyze the composition of many inositol-based products currently used to treat Polycystic Ovary Syndrome (PCOS). Several different combinations of myo-inositol and D-chiro-inositol, with and without additional compounds such as micro- and macroelements, vitamins, and alpha-lipoic acid, have been formulated over the years. Such therapeutic proposals do not take various features of inositol stereoisomers into consideration. As an example, it is important to know that D-chiro-inositol treatment may be beneficial when administered in low doses, yet the progressive increase of its dosage results in the loss of its advantageous effects on the reproductive performance of women and a deterioration in the quality of blastocysts created via in vitro fertilization (IVF). In addition, we have to consider that the intestinal absorption of myo-inositol is reduced by the simultaneous administration of D-chiro-inositol since the two stereoisomers compete with each other for the same transporter that has similar affinity for each of them. A decrease in myo-inositol absorption is also found when it is coadministered with inhibitors of sugar intestinal absorption and/or types of sugars such as sorbitol, maltodextrin, and sucralose. The combination of these may require higher amounts of myo-inositol in order to reach a therapeutic dosage compared to inositol administration alone, a particularly important fact when physicians strive to obtain a specific plasma level of the stereoisomer. Finally, we must point out that D-chiro-inositol was found to be an aromatase inhibitor which increases androgens and may have harmful consequences for women. Therefore, the inositol supplements used in PCOS treatment must be carefully defined. Clinical evidence has demonstrated that the 40 : 1 ratio between myo-inositol and D-chiro-inositol is the optimal combination to restore ovulation in PCOS women. Therefore, it is quite surprising to find that inositol-based treatments for PCOS seem to be randomly chosen and are often combined with useless or even counterproductive molecules, all of which can weaken myo-inositol's efficacy. Such treatments clearly lack therapeutic rationale.

Inositols' Importance in the Improvement of the Endocrine-Metabolic Profile in PCOS

Polycystic ovary syndrome (PCOS) is one of the most common causes of infertility and metabolic problems among women of reproductive age. The mechanism of PCOS is associated with concurrent alterations at the hormonal level. The diagnosis assumes the occurrence of three interrelated symptoms of varying severity, namely ovulation disorders, androgen excess, or polycystic ovarian morphology (PCOM), which all require a proper therapeutic approach. The main symptom seems to be an increased androgen concentration, which in turn may contribute to different metabolic disorders. A number of papers have demonstrated the significant role of inositol therapy in PCOS. However, there is a lack of detailed discussion about the importance of myo-inositol (MI) and d-chiro-inositol (DCI) in reference to particular symptoms. Thus, the aim of this review is to present the effectiveness of MI and DCI treatment for PCOS symptoms. Moreover, the review is focused on analyzing the use of inositols, taking into account their physiological properties, together with the mechanism of individual PCOS symptom formation.

Myo-inositol and D-chiro-inositol (40:1) reverse histological and functional features of polycystic ovary syndrome in a mouse model

Mice exposed to continuous light undergo functional and histological changes that mimic those of human Polycystic Ovary Syndrome (PCOS). We herein induced the syndrome by exposing 30-day-old females to 10 weeks of permanent light. Ovarian morphology and histology, as well as reproductive parameters (time of observed pregnancy/delivery) were investigated. Ovaries of PCOS-modeled mice showed lack of tertiary follicles and corpora lutea, altered ovarian architecture, and increased thickness of the theca layer. When mice were returned to a normal light-dark regimen for 10 days, a slight, spontaneous improvement occurred, whereas a quick and almost complete recovery from PCOS signs and symptoms was obtained by treating animals with a daily supplementation of 420 mg/kg myo-inositol and D-chiro-inositol (MyoIns/DCIns) in a 40:1 molar ratio. Namely, ovaries from mice treated by this protocol recovered normal histological features and a proper ratio of theca/granulosa cell layer thickness (TGR), suggesting that the androgenic phenotype was efficiently reversed. Indeed, we identified TGR as a useful index of PCOS, as its increase in PCOS-modeled mice correlated linearly with reduced reproductive capability ( r = 0.75, p < 0.0001). Mice treated with a 40:1 formula regained low TGR values and faster recovery of their fertility, with a physiological delivery time after mating. On the other hand, a higher D-chiro-inositol treatment formula, such as MyoIns versus DCIns 5:1, was ineffective or even had a negative effect on clinical-pathological outcomes.

Inositol supplement improves clinical pregnancy rate in infertile women undergoing ovulation induction for ICSI or IVF-ET

OBJECTIVE

Pretreatment of myoinositol is a very new method that was evaluated in multiple small studies to manage poor ovarian response in assisted reproduction. This study was to determine the efficacy of myoinositol supplement in infertile women undergoing ovulation induction for intracytoplasmic sperm injection (ICSI) or in vitro fertilization embryo transfer (IVF-ET).

METHODS

A meta-analysis and systematic review of published articles evaluating the efficacy of myo-inositol in patients undergoing ovulation induction for ICSI or IVF-ET was performed.

RESULTS

Seven trials with 935 women were included. Myoinositol supplement was associated with significantly improved clinical pregnancy rate [95% confidence interval (CI), 1.04-1.96; P = .03] and abortion rate (95% CI, 0.08-0.50; P = .0006). Meanwhile, Grade 1 embryos proportion (95% CI, 1.10-2.74; P = .02), germinal vescicle and degenerated oocytes retrieved (95% CI, 0.11-0.86; P = .02), and total amount of ovulation drugs (95% CI, -591.69 to -210.39; P = .001) were also improved in favor of myo-inositol. There were no significant difference in total oocytes retrieved, MII stage oocytes retrieved, stimulation days, and E2 peak level.

CONCLUSIONS

Myoinositol supplement increase clinical pregnancy rate in infertile women undergoing ovulation induction for ICSI or IVF-ET. It may improve the quality of embryos, and reduce the unsuitable oocytes and required amount of stimulation drugs.

Inositol Treatment and ART Outcomes in Women with PCOS

Polycystic ovary syndrome (PCOS) affects 5-10% of women in reproductive age and is characterized by oligo/amenorrhea, androgen excess, insulin resistance, and typical polycystic ovarian morphology. It is the most common cause of infertility secondary to ovulatory dysfunction. The underlying etiology is still unknown but is believed to be multifactorial. Insulin-sensitizing compounds such as inositol, a B-complex vitamin, and its stereoisomers (myo-inositol and D-chiro-inositol) have been studied as an effective treatment of PCOS. Administration of inositol in PCOS has been shown to improve not only the metabolic and hormonal parameters but also ovarian function and the response to assisted-reproductive technology (ART). Accumulating evidence suggests that it is also capable of improving folliculogenesis and embryo quality and increasing the mature oocyte yield following ovarian stimulation for ART in women with PCOS. In the current review, we collate the evidence and summarize our current knowledge on ovarian stimulation and ART outcomes following inositol treatment in women with PCOS undergoing in vitro fertilization (IVF) and/or intracytoplasmic sperm injection (ICSI).

Effect of myo-inositol and melatonin versus myo-inositol, in a randomized controlled trial, for improving in vitro fertilization of patients with polycystic ovarian syndrome

Polycystic ovarian syndrome (PCOS) induces anovulation in women of reproductive age, and is one of the pathological factors involved in the failure of in vitro fertilization (IVF). Indeed, PCOS women are characterized by poor quality oocytes. Therefore, a treatment for enhancing oocyte quality becomes crucial for these patients. Myo-Inositol and melatonin proved to be efficient predictors for positive IVF outcomes, correlating with high oocyte quality. We tested the synergistic effect of myo-inositol and melatonin in IVF protocols with PCOS patients in a randomized, controlled, double-blind trial. Five-hundred twenty-six PCOS women were divided into three groups: Controls (only folic acid: 400 mcg), Group A (Inofolic® plus, a daily dose of myo-inositol: 4000 mg, folic acid: 400 mcg, and melatonin: 3 mg), and Group B (Inofolic®, a daily dose of myo-inositol: 4000 mg, and folic acid: 400 mcg). The main outcome measures were oocyte and embryo quality, clinical pregnancy and implantation rates. The treatment lasted from the first day of the cycle until 14 days after embryo transfer. Myo-inositol and melatonin have shown to enhance, synergistically, oocyte and embryo quality. In consideration of the beneficial effect observed in our trial and on the bases of previous studies, we decided to integrate routinely MI and M supplementation in the IVF protocols. The same treatment should be taken carefully in consideration in all procedures of this kind.

Reflections on inositol(s) for PCOS therapy: steps toward success

In polycystic ovary syndrome (PCOS) pathogenesis, both the insulin resistance and the related compensatory hyperinsulinemia are involved. Despite their similarities, Myo-inositol (MI) and d-chiro-inositol (DCI) play different roles in PCOS etiology and therapy. Indeed, in tissue such as the liver both molecules are involved in the insulin signaling, i.e. MI promotes glucose uptake and DCI glycogen synthesis. In reproductive tissue such as the ovary, MI regulates glucose uptake and follicle stimulating hormone (FSH) signaling, whereas DCI is devoted to the insulin-mediated androgen production. The new hypothesis on "DCI paradox" in the ovary has provided the key for a better understanding. Unlike other tissues, ovary is not insulin resistant, indeed because the epimerase enzyme, which converts MI to DCI, is insulin dependent, the "DCI paradox" hypothesis suggests that in the ovary of PCOS women, an increased epimerase activity leads to a DCI overproduction and MI depletion. This imbalance could be the cause of the poor oocyte quality and the impairment in the FSH signaling. Owing to this situation, the focal point is the administration of both MI and DCI in a proper ratio for treating PCOS. This topic, with several other "hot" issues, was the driving thread in the discussion between the two scientists.

Myo-inositol therapy for poor-responders during IVF: a prospective controlled observational trial

Background

The overall incidence of poor ovarian response in IVF cycles has been reported to be between 9 and 24 %. The management of these patients remains a significant challenge in assisted reproduction. The aim of the present study was to evaluate the effect of myo-inositol (MI) on ovarian function in poor responders undergoing ICSI.

Methods

The study is a prospective controlled observational trial, that involved 72 poor responders included in an ICSI program and divided into two groups; group A: 38 patients who have been assuming MI (4 g) + folic acid (FA) (400 μg) for the previous 3 months before the enrollment day; group B: 38 patients assuming FA (400 μg) alone for the same period. COH was carried out in the same manner in the two groups. The main goal was the assessment of oocytes retrieved number and quality; secondary endpoints were the Ovarian Sensitivity Index (OSI: n° oocytes retrieved/total Gonadotropins units × 1000), oestradiol levels on the day of hGC, fertilization rate, implantation rate, ongoing pregnancy rate.

Results

There was no significant difference between the two groups regarding oestradiol level, but total rec-FSH units were significantly lower (p = 0.004) and M2 oocytes rate significantly higer (p = 0.01) in group A. The ovarian sensitivity index was higher, reaching a statistical significance (p < 0.05), in the group of patients pre-treated with MI, showing an improvement in ovarian sensibility to gonadotropin.

Conclusions

Our results suggest that MI therapy in poor responders results in an increased of the number of oocytes recovered in MII and of the gonadotropin Ovarian Sensitivity Index (OSI), suggesting a MI role in improving ovarian response to gonadotropins. Therefore MI seems to be helpful in “poor responders” undergoing IVF cycles.

Results from the International Consensus Conference on myo-inositol and D-chiro-inositol in Obstetrics and Gynecology--assisted reproduction technology

A substantial body of research on mammalian gametogenesis and human reproduction has recently investigated the effect of myo-inositol (MyoIns) on oocyte and sperm cell quality, due to its possible application to medically assisted reproduction. With a growing number of both clinical and basic research papers, the meaning of several observations now needs to be interpreted under a solid and rigorous physiological framework. The 2013 Florence International Consensus Conference on Myo- and D-chiro-inositol in obstetrics and gynecology has answered a number of research questions concerning the use of the two stereoisomers in assisted reproductive technologies. Available clinical trials and studies on the physiological and pharmacological effects of these molecules have been surveyed. Specifically, the physiological involvement of MyoIns in oocyte maturation and sperm cell functions has been discussed, providing an answer to the following questions: (1) Are inositols physiologically involved in oocyte maturation? (2) Are inositols involved in the physiology of spermatozoa function? (3) Is treatment with inositols helpful within assisted reproduction technology cycles? (4) Are there any differences in clinical efficacy between MyoIns and D-chiro-inositol? The conclusions of this Conference, drawn depending on expert panel opinions and shared with all the participants, are summarized in this review paper.

The rationale of the myo-inositol and D-chiro-inositol combined treatment for polycystic ovary syndrome

PCOS is one of the most common endocrine disorders affecting women and it is characterized by a combination of hyper-androgenism, chronic anovulation, and insulin resistance. While a significant progress has recently been made in the diagnosis for PCOS, the optimal infertility treatment remains to be determined. Two inositol isomers, myo-inositol (MI) and D-chiro-inositol (DCI) have been proven to be effective in PCOS treatment, by improving insulin resistance, serum androgen levels and many features of the metabolic syndrome. However, DCI alone, mostly when it is administered at high dosage, negatively affects oocyte quality, whereas the association MI/DCI, in a combination reproducing the plasma physiological ratio (40:1), represents a promising alternative in achieving better clinical results, by counteracting PCOS at both systemic and ovary level.

Myoinositol: a new marker of intrauterine growth restriction?

Inositol is a cyclic sugar alcohol which occurs naturally in a variety of stereoisomers, the most common of which is myo-inositol. Inositol phosphoglycan molecules have been isolated from mammalian tissues and are a major component of the intracellular mediators of insulin action. The fetus with intrauterine growth retardation (IUGR) activates a series of adaptive mechanisms to increase the chances for survival, such as a saving of glucose to ensure nutrition of the vital organs, with a consequent reduction in insulin secretion. It can be hypothesized that the reduced production of fetal insulin leads to an excretion of inositol from the intracellular to the extracellular compartment, with a consequent increase of the metabolite in plasma and urine and a decrease inside the cells. Recently, reports suggesting that the increase in extracellular myo-inositol may be a valid marker of an altered glucose metabolism during fetal development in IUGR have been published.

Improvement of mouse embryo quality by myo-inositol supplementation of IVF media

OBJECTIVE

Myo-inositol (myoIns) has a positive role in mammalian development and human reproduction. Since experiments on farming species suggest a similar role in preimplantation development, we evaluated the hypothesis that the inclusion of myoIns in human embryo culture media would produce an increase in embryo quality in IVF cycles, using the mouse embryo assay.

METHODS

To determine the effect of myoIns on completion of preimplantation development in vitro, one-cell embryos of the inbred C57BL/6N mouse strain were produced by ICSI, cultured in human fertilization media in the presence of myoIns (myoIns+) or in its absence (myoIns-) and evaluated morphologically. Daily progression through cleavage stages, blastocyst production and expansion and blastomere number at 96 hours post fertilization were assessed.

RESULTS

Compared to myoIns- embryos, myoIns+ embryos displayed a faster cleavage rate and by the end of preimplantation development, the majority of myoIns+ blastocysts was expanded and formed by a higher number of blastomeres.

CONCLUSION

The presence of myoIns resulted in both an increase in proliferation activity and developmental rate of in vitro cultured early mouse embryos, representing a substantial improvement of culture conditions. These data may identify myoIns as an important supplement for human embryo preimplantation culture.

Pretreatment with myo-inositol in non polycystic ovary syndrome patients undergoing multiple follicular stimulation for IVF: a pilot study

BACKGROUND

Aim of this pilot study is to examine the effects of myo-inositol administration on ovarian response and oocytes and embryos quality in non PolyCystic Ovary Syndrome (PCOS) patients undergoing multiple follicular stimulation and in vitro insemination by conventional in vitro fertilization or by intracytoplasmic sperm injection.

METHODS

One hundred non-PCOS women aged <40 years and with basal FSH <10 mUI/ml were down-regulated with triptorelin acetate from the mid-luteal phase for 2 weeks, before starting the stimulation protocol for oocytes recovery. All patients received rFSH, at a starting dose of 150 IU for 6 days. The dose was subsequently adjusted according to individual response. Group B (n=50) received myo-inositol and folic acid for 3 months before the stimulation period and then during the stimulation itself. Group A (n-50) received only folic acid as additional treatment in the 3 months before and through treatment.

RESULTS

Total length of the stimulation was similar between the two groups. Nevertheless, total amount of gonadotropins used to reach follicular maturation was found significantly lower in group B. In addition, the number of oocytes retrieved was significantly reduced in the group pretreated with myo-inositol. Clinical pregnancy and implantation rate were not significantly different in the two groups.

CONCLUSIONS

Our findings suggest that the addition of myo-inositol to folic acid in non PCOS-patients undergoing multiple follicular stimulation for in-vitro fertilization may reduce the numbers of mature oocytes and the dosage of rFSH whilst maintaining clinical pregnancy rate. Further, a trend in favor of increased incidence of implantation in the group pretreated with myo-inositol was apparent in this study. Further investigations are warranted to clarify this pharmacological approach, and the benefit it may hold for patients.

Optimized hormonal stimulation is critical for production of viable embryos and establishment of subsequent implantation

PURPOSE

To investigate the effects of follicle number and size at the time of hCG administration, and ovarian stimulation length on the outcome of in vitro fertilization and pregnancy rate.

METHODS

During the ovarian stimulation regimen, the follicular number and size were determined by transvaginal ultrasonographic examination. Ovulation was induced as early as three or more follicles were at least 16 mm in their greatest diameter.

RESULTS

The fertilization rates were significantly increased with the longer length of stimulation (10-12 days: 75.4% and 13-16 days: 83.2%). However, no significant differences in the chemical pregnancy, clinical pregnancy, and implantation rates were found between 10-12 days (53.7%, 43.9%, and 21.8%) and 13-16 days (50.0%, 43.8%, and 23.4%) of stimulation. There were no significant differences in fertilization and chemical pregnancy rates between two groups with > or = and <18 follicles in the ovaries on the day of hCG (human chorionic gonadotrophin) administration. However, the clinical pregnancy and implantation rates (47.2% and 26.0%) in the group with <18 follicles were significantly higher than those (33.3% and 15.5%) in the group with > or =18 follicles, respectively.

CONCLUSIONS

Excessive and rapid ovarian stimulation appears to decrease the survival of embryos at later stages after transfer. The advantage of prolonged stimulation may outweigh the potential adverse effects in some patients.

Follicular fluid and serum concentrations of myo-inositol in patients undergoing IVF: relationship with oocyte quality

BACKGROUND

The follicular microenvironment is an important determinant of oocyte development. The aim of this study was to examine whether the myo-inositol (MI) content in human follicular fluid (FF) was associated with better oocyte quality.

METHODS

A total of 53 patients treated with IVF was recruited to a prospective observational study. FF and serum samples collected were divided into two groups: group A consisted of FF associated with matured and fertilized oocytes, whilst group B was from follicles with immature and unfertilized oocytes.

RESULTS

Patient's age, total ampoules of HMG used, days of stimulation, basal levels of FSH, estradiol (E(2)) levels on the day of HCG, and serum MI content were not significantly different between the two groups. FF volume and its MI content were significantly higher in group A compared with group B (P < 0.05). The levels of MI in FF were positively correlated with the amount of E(2) in their corresponding FF samples and also correlated with embryo quality.

CONCLUSIONS

We propose that higher concentrations of MI and E(2) in human FF appear to play a role in follicular maturity and provide a marker of good quality oocytes.

High bovine blastocyst development in a static in vitro production system using SOFaa medium supplemented with sodium citrate and myo-inositol with or without serum-proteins

We describe a bovine embryo culture system that supports repeatable high development in the presence of serum or BSA as well as under defined conditions in the absence of those components. In the first experiment, embryo development in SOF with amino acids (SOFaa), sodium citrate (SOFaac) and myo-inositol (SOFaaci) and with BSA or polyvinyl alcohol (PVA) was compared with that in a M199 granulosa cell co-culture (M199 co-culture). Subsequently, development and cell numbers of blastocysts cultured under defined conditions in SOFaaci with PVA (SOFaaci-PVA), or under undefined conditions in SOFaaci with 5% cow serum (SOFaaci-CS) or M199 co-culture were compared. The repeatability of culture results in SOFaaci-CS was checked by weekly replicates (n = 30) spread over 11 months. The viability of embryos developed in SOFaaci-PVA was estimated by transfer of morphologically good blastocysts (n = 10) to synchronized recipients. In the second experiment, the effect of omitting CS or BSA from IVM and IVM-IVF on subsequent embryo development in SOFaaci-PVA or in SOFaaci-CS was investigated. Blastocyst development in SOFaa-PVA, SOFaac-PVA, SOFaa-BSA and M199 was 16 +/- 3b, 23 +/- 2ab, 30 +/- 8a and 36 +/- 7a%, respectively (Pab < 0.05). Additional inclusion of myoinositol resulted in 42 +/- 1a% blastocysts in SOFaaci-PVA vs 19 +/- 3b% in SOFaac-PVA, 47 +/- 7a% in SOFaac-BSA, and 36 +/- 7a% in M199 co-culture, respectively (Pab < 0.01). In 30 replicates, the average cleavage and blastocyst rates of oocytes in SOFaaci-CS were 87 +/- 4 and 49 +/- 5%, respectively. Five normal calves were produced after transfer of 10 blastocysts developed in defined culture medium (i.e., SOFaaci-PVA). Defined IVM or IVM-IVF (i.e., in absence of CS and BSA) reduced cleavage rates (83 +/- 3 and 55 +/- 3% vs 90 +/- 1% in presence of CS; P < 0.01). Subsequent embryo development in SOFaaci-CS was not affected in either of these defined conditions. However, cleavage and blastocyst rates under completely defined IVP conditions were 54 +/- 7 and 19 +/- 4%, respectively. It was concluded that under defined culture conditions, addition of citrate and myo-inositol improved blastocyst development to rates comparable to those obtained with serum, BSA or co-culture and that the quality of blastocysts was not affected by the absence of serum or BSA. However, serum was essential during IVM/IVF for normal fertilization and subsequent high blastocyst development.

A new long shelf life formulation of modified Ham's F-10 medium: biochemical and clinical evaluation

PURPOSE

To evaluate biochemically and clinically a new formulation of modified Ham's F-10 medium made without the inclusion of hypoxanthine. The medium was formulated for long-term storage and use by separately preparing a stable liquid ("basal") portion and a freeze-dried "supplement" containing the labile medium components.

RESULTS

Following 18 months of storage the basal medium was biochemically analyzed for its amino acid (aa's) and vitamin content. Cysteine and tryptophan were decreased to less than 30% of their starting theoretical concentrations (STCs). Asparagine, serine, tyrosine, histidine and lysine were present at 50% to 70% of their STC. The remaining aa's were all within 90% of their STCs except arginine which was at 77%. All of the vitamins were present at 90% or more of their STCs except inositol, riboflavin and thiamine which were present at 70% of their STCs. IVF with the new formulation resulted in 13 deliveries from 51 aspirations (25%) as compared with 10/39 (26%) in 1991, when standard medium preparation was used. Oocyte donation resulted in 30 deliveries from 84 cycles (36%) with the new formulation as compared with 21/65 (32%) in 1991.

CONCLUSIONS

(1) The new basal with lyophilized supplement formulation produces similar clinical results in the IVF laboratory as medium prepared in the standard fashion, (2) certain amino acids and vitamins are not stable in the liquid basal medium, and (3) the separate formulation of a liquid basal medium with lyophilized supplement is convenient, viable alternative to modified Ham's F-10 medium prepared in the standard manner (i.e., from powder) and may decrease the need for frequent medium preparation.

Effect of follicular size on oocyte retrieval, fertilization, cleavage, and embryo quality in in vitro fertilization cycles: a 6-year data collection

OBJECTIVE

To determine the effect of follicular size, including the size of the leading follicle, on oocyte retrieval, fertilization, cleavage, and embryo quality in IVF cycles based on a large data collection.

DESIGN

Retrospective analysis of 1,109 IVF cycles between 1987 and 1993 at the Hospital of the University of Pennsylvania including 606 patients ranging in age from 23 to 49 years.

RESULTS

Follicles with a volume < or = 1 mL show a significantly lower oocyte recovery rate than follicles with a volume of > 1 mL. The highest recovery rate (83.5%) was found in follicles with a volume of 3 to 4 mL. Above a follicular volume of 7 mL, the oocyte recovery drops below that observed for follicles between 1 and 7 mL. Fertilization and cleavage rates were also higher in oocytes obtained from follicles > 1 mL compared with follicles < or = 1 mL. Although fertilization rates were fairly stable above volumes of 1 mL, cleavage rates continued to rise to a peak percentage of 92% with volumes between 6 and 7 mL. Leading follicle size did not have an effect on fertilization and cleavage rates of cohort oocytes. Embryo quality was not influenced significantly by follicular volume.

CONCLUSION

Based on this evaluation of a large number of follicles, follicular size is a useful indicator of oocyte recovery, fertilization, and cleavage in IVF cycles. For optimal results, the follicular fluid volume in gonadotropin- and hCG-stimulated cycles should be > 1 mL, which corresponds to a follicle diameter of > 12 mm, and not larger than 7 mL (24 mm). For timing of hCG administration, the number of adequate size follicles appears to be more important than the size of the leading follicle(s).