Predictive value of the level of vitamin D in follicular fluid on the outcome of assisted reproductive technology

Positive Effect of 25-Hydroxyvitamin D (25(OH)D) Levels in Follicular Fluid on Embryonic Developmental Potential in Diminished Ovarian Reserve (DOR) Patients Undergoing Microstimulation

OBJECTIVE

This study aimed to explore the effect of 25-hydroxyvitamin D (25(OH)D) levels in follicular fluid (FF) on the embryo outcome with diminished ovarian reserve (DOR) patients undergoing in vitro fertilization (IVF) by microstimulation protocol.

METHODS

A prospective cohort study of 79 patients with DOR who underwent IVF using the microstimulation protocol was conducted. Based on the level of 25(OH)D in follicular fluid (25(OH)D-FF), the patients were divided into a high-value group (25(OH)D-FF>11.1, n = 50) and a low-value group (25(OH)D-FF>11.1, n = 29). Correlation analysis was conducted between the level of 25(OH)D-FF and the rate of high-quality embryos on day 3 (D3). Logistic regression analysis of factors affecting the presence or absence of D3-available embryos in patients with DOR was conducted.

RESULTS

The number of oocytes retrieved, mature oocytes (MII), normal fertilization rate, number of available embryos on D3, and high-quality embryo rate were lower in the low-value group than in the high-value group (p = 0.000, p = 0.000, p = 0.009, p = 0.000, p = 0.001). The clinical pregnancy rate of frozen embryo transfer (FET) between the two groups was no statistically significant difference (p > 0.05); correlation analysis between the 25(OH)D-FF level and the rate of high-quality embryos was performed using Spearman's rank-sum test, and there was a positive correlation (R = 0.271, P<0.01). Logistic analysis showed that 25(OH)D-FF level was a protective factor for embryonic outcome (odds ratio (OR) > 1, P<0.01).

CONCLUSION

The 25(OH)D level in FF has a positive effect on embryonic outcomes in DOR patients with IVF using the microstimulation protocol. Vitamin D (VD) supplementation can be used to increase the number of available embryos and improve the quality of embryos for patients with DOR who are undergoing microstimulation of IVF.

The Key Role of Vitamin D in Female Reproductive Health: A Narrative Review

Vitamin D, besides its crucial role in bone health and immune function, has received increased attention in recent years due to its possible impact on many processes related to female reproductive health. Recent research has tried to explain the role played by vitamin D in maintaining adequate hormonal status, fertility, and pregnancy outcomes. Our aim for this narrative literature review was to highlight and explain the mechanisms through which vitamin D status impacts female reproductive health. We believe this represents a very important subject of research, especially due to the increased incidence of infertility nowadays. Further studies are necessary on the association between vitamin D status and female reproductive health in order to fully understand its effects and to reach a consensus regarding vitamin D supplementation as a method to improve fertility status.

The therapeutic effects of vitamin D3 administration on the embryo implantation

Various adjuvants have been tested clinically for patients with problems with embryo implantation during in vitro fertilization (IVF)-embryo transfer (ET). Vitamin D3, an essential modulator of various physiological processes, has received attention as an important adjuvant for successful pregnancy, as many studies have shown a strong association between vitamin D deficiency and implantation failure and fetal growth restriction. However, vitamin D has been widely utilized in different protocols, resulting in non-reproducible and debatable outcomes. In the present study, we demonstrated that cyclic intrauterine administration of vitamin D3 increased endometrial receptivity and angiogenesis, which could be attributed to increased recruitment of uterus-resident natural killer cells. In particular, cyclic treatment of vitamin D3 promoted stable attachment of the embryo onto endometrial cells in vitro, suggesting its merit during the early stage of embryo implantation to support the initial maternal-fetal interactions. Our findings suggest that women with repeated implantation failure may benefit from the use of vitamin D3 as a risk-free adjuvant prior to IVF-ET procedures to improve the uterine environment, and make it favorable for embryo implantation.

Association Between Vitamin D Level and Clinical Outcomes of Assisted Reproductive Treatment: A Systematic Review and Dose-Response Meta-Analysis

The investigation about association between vitamin D level and clinical outcomes of assisted reproductive treatment showed various outcomes. This study aimed to review the correlation between vitamin D and outcomes of assisted reproductive treatment. The search was registered on the PROSPERO database (CRD42023458040). PubMed, Embase, Medline, ClinicalTrials.gov, and Cochrane databases were searched up to July 2023. Twenty-three observational studies were selected for meta-analysis. Comparing groups with deficient and 'insufficient + sufficient' vitamin D level, meta-analysis showed positive correlation between clinical pregnancy rate and vitamin D (OR 0.81, 95%CI: 0.70, 0.95, P = 0.0001). Comparing groups with 'deficient + insufficient' and sufficient vitamin D level, meta-analysis showed positive correlation between vitamin D and clinical pregnancy rate (OR 0.71, 95%CI: 0.55, 0.91, P = 0.006), vitamin D and live birth rate (OR 0.69, 95%CI: 0.54, 0.89, P = 0.003). Subgroup analysis did not show the source of high heterogeneity. No correlation was found in biochemical pregnancy rate, ongoing pregnancy rate, miscarriage rate and implantation rate. In dose-response meta-analysis, a nonlinear association was found between vitamin D levels and outcomes when levels are below approximately 24 ng/L. The study shows that vitamin D level is associated with clinical pregnancy rate and live birth rate. Low vitamin D level does not influence biochemical pregnancy rate, ongoing pregnancy rate, miscarriage rate and implantation rate. Furthermore, 24 ng/L may be a possible threshold of vitamin D concentration in assisted reproduction therapy.

Serum Vitamin D Deficiency and Male Infertility: A Relationship?

Background Male infertility is one of the major reproductive health concerns, causing a lot of distress for couples globally. Others have looked into its connection to vitamin D deficiency, but their findings are conflicting. Aim This study aimed to determine the relationship between male infertility and vitamin D deficiency among Nigerians. Method This analytical cross-sectional study was conducted among 132 men. A purposive sampling technique was employed to recruit 66 participants in the study (men with infertility) and control groups (men with proven fertility). Descriptive statistics were conducted, while the association between vitamin D level and sperm parameters was assessed using bivariate and regression modeling. A two-tailed test of the hypothesis was assumed, and the level of statistical significance was set at a P-value < 0.05. Results None of the participants had a serum vitamin D deficiency. However, the overall serum vitamin D insufficiency rate was 15%. The median vitamin D level for the total study population (both fertile and infertile) was 37.52 ng/ml (IQR: 32.1 - 51.69). This study demonstrated no association between serum vitamin D levels and male infertility, as well as no association between serum vitamin D levels and the quality of semen parameters. Conclusion There was no significant association between vitamin D levels, male infertility, and seminal fluid parameters. However, larger multi-center studies are recommended to provide further insights into this conclusion.

Women with PCOS who undergo IVF: a comprehensive review of therapeutic strategies for successful outcomes

Polycystic ovarian syndrome (PCOS) is a widespread syndrome that poses unique challenges and constraints to the field of assisted reproductive technology. This condition is the most common cause of anovulation among infertile couples. Debate exists over the best therapeutic course of action when patients with PCOS proceed to IVF. In this review, we evaluate the best-performing and safest methods of IVF preparation, ovarian stimulation, trigger method for maturation of stimulated egg growth, and planning for embryo transfer. Pre-IVF considerations include being aware of individual AMH and vitamin D levels as well as BMI prior to selecting an ovarian stimulation protocol. Numerous supplements such as myo-inositol complement the benefits of lifestyle change and may enhance IVF performance including oocyte yield and pregnancy rate. Concerning stimulation protocols, antagonist cycles with the judicious use of GnRH agonist trigger, pre-treatment with metformin and vitamin D repletion may help mitigate the accompanied risk of ovarian hyperstimulation syndrome (OHSS). Following ovarian stimulation, PCOS patients typically undergo programmed frozen embryo transfer (FET) cycles which are more conducive for women with irregular cycles, but likely carry a higher risk of hypertensive disorders of pregnancy. However, newer stimulated FET protocols using Letrozole may offer improved outcomes. Overall, patients with PCOS require careful individual tailoring of their IVF cycle to achieve optimal results.

Evaluation of the relationship between vitamin D levels with oocyte quality in breast cancer women: a cross-sectional study

Recent evidence suggests that vitamin D deficiency could play an important role in the development of non-skeletal diseases, including cancer. Vitamin D also affects the function of the reproductive system. In the present study, the relationship between 25(OH)D levels with oocyte quality in Breast Cancer (BC) women and control group have been investigated. After initial evaluations, ovarian stimulation began with the GnRH antagonist protocol in the BC group (N = 16) and control group (N = 16). The serum and follicular fluid (FF) 25(OH)D levels were measured at the time of oocyte retrieval and their relationship to oocyte quality was examined. The mean levels of serum and FF 25(OH)D in BC women were significantly lower than in the control group (22.26 ± 7.98 vs. 29.61 ± 9.12, P = 0.02, 21.65 ± 7.59 vs. 28.00 ± 9.05, P = 0.04, respectively). There was a significant correlation between the levels of 25(OH)D in FF and serum in BC women (r = 0.873, P < 0.001). But there was no correlation between the serum or FF 25(OH)D levels with the parameters related to oocytes (P > 0.05). In the BC women, the number of dysmorph and highly dysmorph oocytes was higher than in the control group (P < 0.001). Women with BC referring to infertility centers for fertility preservation are more likely to be deficient in serum 25(OH)D level; this subsequently affects the FF 25(OH)D level. However, serum and FF 25(OH)D levels may not be suitable indicators for examining maturity and quality of oocytes in terms of morphology in BC women, and the poor morphological quality of oocytes in BC women may be due to other factors.

Genetic association of vitamin D receptor gene with female infertility

BACKGROUND

Infertility is defined as failure to achieve a clinical pregnancy after 12 months of unprotected intercourse. It affects 15% of couples globally and 22% of couples within Pakistan. Female infertility can be caused by numerous genetic or environmental factors including hormone imbalances and exposure to chemicals or radiation. The prevalence of vitamin D deficiency among the adult population was reported to be 14-59% with a higher prevalence in Asian countries. Furthermore, the expression of Vitamin D receptor (VDR) can play a vital role in the reproductive organs of females. Hence, the aim of our present study was to check the association of VDR polymorphisms with infertile females. For this purpose, blood samples were collected for genotyping of four known VDR mutations [FokI (rs2228570), TaqI (rs731236), ApaI (rs7975232), and BsmI (rs1544410)] via PCR-based RFLP assay.

RESULTS

Genotyping indicated that FokI, TaqI, and ApaI are associated with infertility (p = 0.004*, p = 0.013*, and p = 0.033*, respectively). However, BsmI did not show any significance. Multinomial regression analysis indicated that FokI heterozygous genotypes increase the risk of infertility by 2.5 times (hetero: OR = 2.5, 95%, p = 0.001*) as compared to wild type. Heterozygous genotypes of TaqI and ApaI were found to play a protective role and reduce the risk of infertility by 58 and 52%, respectively [TaqI: OR = 0.42, 95%, p = 0.004*, ApaI: OR = 0.48, 95%, p = 0.01*, respectively] as compared to wild type. Multinomial logistic regression analysis was also performed for allelic data as well.

CONCLUSION

Thus, it could be summarized that among the studied polymorphisms of VDR, FokI SNP greatly increased the risk of infertility, while TaqI and ApaI genotypes protect from infertility. However, BsmI does not influence the risk of infertility in Pakistani females.

The effect of calcitriol on the development and implantation capacity of embryos from hyper-stimulated mice

The evidence concerning the role of vitamin D (VD) in reproduction is still inconclusive. Calcitriol was given to superovulated female mice at the time of FSH injection (Group A), or at day 0.5 of pregnancy (Group B). The retrieved and cultured embryos were transferred to the uteri of pseudopregnant females. Ten animals from each group conceived naturally, and at day 7.5 of pregnancy, the implantation sites were counted. Serum hormone concentrations were determined by ELISA. The expression of CD70, PD-L1, OX-40L, and PIBF on extracellular vesicles (EVs) was tested by flow cytometry. Calcitriol treatment did not alter serum oestradiol concentrations, while 25(OH) D levels significantly decreased in both treated groups. Progesterone concentrations were significantly higher in group A and lower in group B than in the controls. On EVs produced by group B embryos PIBF, CD70, and OX-40L expression were significantly lower, while that of PD-L1 was significantly higher than that of controls. Calcitriol treatment decreased the fertilization rate in group A, and the blastulation rate of cultured embryos in group B, while the implantation capacity of the embryos was not affected, suggesting that depending on the time of administration, VD has an adverse effect on oocyte maturation and embryo development, but not on the implantation rates.

Vitamin D Status in Women with a History of Infertility and Decreased Fecundability: A Population-Based Study

BACKGROUND

Infertility and fecundability problems have been linked with lower 25-hydroxyvitamin D (25(OH)D) concentrations, but studies conducted with small, heterogenous or selected populations have shown inconsistent results.

METHODS

This study included women at age 31 from prospective population-based Northern Finland Birth Cohort 1966. Serum 25(OH)D concentrations were evaluated between women with or without previous infertility examinations or treatments (infertility group, n = 375, reference group, n = 2051) and time to pregnancy (TTP) of over 12 months (decreased fecundability group, n = 338) with a wide range of confounders. Furthermore, 25(OH)D concentrations were also compared among reproductive outcomes.

RESULTS

The mean 25(OH)D concentration was lower and 25(OH)D < 30 nmol/L was more frequent in women with a history of infertility compared to reference group. Moreover, 25(OH)D > 75 nmol/L was more frequent in the reference group. The mean 25(OH)D concentration was lower in women who had had multiple miscarriages. Both history of infertility (β = -2.7, 95% confidence interval (CI) -4.6, -0.7) and decreased fecundability associated with lower 25(OH)D concentration (β = -4.1, 95% CI -7.4, -0.8) after adjustments. In conclusion, this population-based study demonstrated that previous infertility and decreased fecundability were associated with lower 25(OH)D.

Correlation between 25-hydroxy vitamin D levels in women and in vitro fertilization outcomes: A cross-sectional study

Background

Vitamin D has recently raised a great deal of controversy, not because of its traditional role of absorbing calcium and maintaining bone health, but because of its unconventional role as an endocrine factor and the extent of its impact when linked to its specific receptors (VDR) found in different tissues. Research has raced trying to find its different roles in those tissues and its association with different clinical or medical conditions, and among these cases, its role in reproductive functions and fertility in women, these studies conflicted between supporting and denying the role of vitamin D in reproductive function and rejecting this hypothesis according to the results of their study.

Materials and methods

The in vitro fertilization process allowed us to study the possible hypotheses, as this technique provides an opportunity to study the relationship between vitamin D levels with the in vitro fertilization outcomes, thus providing us with an idea of the relationship of vitamin D with fertility in women. In order to study this relationship, we designed our research as a cross-sectional study to confirm or deny this claim. Vitamin D was measured in the blood and in the follicular fluid for all cases using the electrochemiluminescence immunoassay (ECLIA) for the assay of total vitamin D, then IVF outcomes were compared with the levels of vitamin D in the blood.

Results

the levels of vitamin D are not related to the criteria of eggs such as the number of eggs and the maturity rate (MR) of eggs, but they are correlated in a statistically significant manner with the fertility rate (FR), and at the same time the levels of vitamin D in the blood were completely independent of the clinical pregnancy rate (CPR).

Conclusion

blood vitamin D levels will affect the FR when its levels in the blood drop below a specified value, vitamin D did not correlate with the CPR. In the long run, there is scope for more research projects on vitamin D. Future research could include case-control studies of patients on vitamin D supplementation, and the study of its correlation with IVF outcomes.

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Vitamin D deficiency affects various body functions including reproductive system in females.

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Appropriate levels of blood 25-hydroxy vitamin D affect the egg fertility rate, while it does not affect the maturity rate.

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Adequate levels of 25-hydroxy vitamin D are not associated with clinical pregnancy rates during in vitro fertilization.

Female infertility and diet, is there a role for a personalized nutritional approach in assisted reproductive technologies? A Narrative Review

Female infertility is a major public health concern and a global challenge. It is a disorder of the reproductive system, defined as the inability to achieve a clinical pregnancy. Nutrition and other environmental factors are found to impact reproductive health in women as well as the outcome of assisted reproductive technologies (ART). Dietary factors, such as polyunsaturated fatty acids (PUFA), fiber as well as the intake of Mediterranean diet appear to exert beneficial effects on female reproductive outcomes. The exact mechanisms associating diet to female fertility are yet to be identified, although genomic, epigenomic, and microbial pathways may be implicated. This review aims to summarize the current knowledge on the impact of dietary components on female reproduction and ART outcomes, and to discuss the relevant interplay of diet with genome, epigenome and microbial composition.

Increasing vitamin D levels to improve fertilization rates in cattle

Recently, interest in supplementing vitamin D (Vit D) to improve aspects of health, mainly in human fertility, has emerged. Still, supplementation of Vit D above the minimum required levels has yet to be explored in cattle despite evidence for Vit D receptors in reproductive tissues. The objective of this study was to establish if a dose-response relationship exists between Vit D exposure and success of in vitro production (IVP) of embryos and, if acute supplementation of Vit D improves pregnancy rates during timed artificial insemination (TAI) of dairy cows. Cumulus-oocyte complexes (COCs) were obtained from ovaries acquired from a local abattoir and cultured in five different IVP treatments from three separate collections (Control, 50, 100, 150, and 200 ng/mL of 1,25(OH)2D3; n = 20-30 COCs/group). In Experiment 2, dairy breed cows (n = 100) were synchronized for TAI with the PresynchOvsynch protocol. Cows received 150,000 IU of Vit D (n = 48) or castor oil as control (n = 53) along with gonadotropin-releasing hormone (GnRH) 24 h before TAI. Serum samples were collected before and 24 h after treatment. A small cohort of cows (n = 4) received the same treatments in two separate cycles and follicular fluid (FF) was collected after 24 h for calcidiol (25OHD) analyses. Increased concentrations of Vit D resulted in decreased rates of maturation of COC (150 and 200 ng/mL vs. control and 50 ng/mL; P = 0.01). Supplementation with 50 ng/mL resulted in greater numbers of early blastocyst and blastocyst stage embryos (P < 0.009). Pregnancy at first breeding did not differ (P = 0.13) between groups, but serum 25OHD increased in treated females after 24 h (P = 0.002). The FF 25OHD levels were reflective of serum levels, however, the observed increase in the treatment cycle (P = 0.04) was parallel to an overall increase in serum 25OHD during the entire second cycle, likely due to increased environmental sunlight exposure (March, control vs. May, treatment). A similar increase in the serum 25OHD in the lactating commercial herd maintained in covered housing was not observed, although experiments were conducted during a similar timeframe. This herd had levels of 25OHD near the low end of sufficiency according to National Research Council (NRC) guidelines. We conclude mild Vitamin D supplementation with concentrations at the higher end of NRC guidelines can improve maturation rates of recovered COCs. However, longer term supplementation may be needed to appreciate any benefits on fertility.

Calcifediol (25OHD) Deficiency and Its Treatment in Women's Health and Fertility

Currently, there is abundant scientific evidence showing that the vitamin D endocrine system (VDES) is a highly complex endocrine system with multiple actions in different regions of the body. The unequivocal presence of vitamin D receptors in different tissues related to fertility, and to specific aspects of women's health such as pregnancy, undoubtedly implies functions of this steroid hormone in both male and female fertility and establishes relationships with different outcomes of human gestation. In order to review the role of the VDES in human fertility, we evaluated the relationships established between 25-hydroxyvitamin D (calcifediol) deficiency and in vitro fertilization, as well as aspects related to ovarian reserve and fertility, and commonly diagnosed endocrinopathies such as polycystic ovary disease. Likewise, we briefly reviewed the relationships between calcifediol deficiency and uterine fibroids, as well as the role that treatment may have in improving human fertility. Finally, the best scientific evidence available on the consequences of calcifediol deficiency during pregnancy is reviewed in relation to those aspects that have accumulated the most scientific literature to date, such as the relationship with the weight of the newborn at the time of delivery, the appearance of preeclampsia, and the risk of developing gestational diabetes and its final consequences for the pregnancy. To date, there is no definitive consensus on the necessary dose for treatment of calcifediol deficiency in the therapeutic management of infertility or during pregnancy. Large prospective clinical intervention studies are needed to clarify the benefits associated with this supplementation and the optimal dose to use in each situation. Although most intervention studies to date have been conducted with cholecalciferol, due to its much longer history of use in daily care, the use of calcifediol to alleviate 25-hydroxyvitamin D deficiency seems safe, even during pregnancy. The unequivocal presence of vitamin D receptors in very different tissues related to human fertility, both male and female, as well as in structures typical of pregnancy, allows us to investigate the crucial role that this steroid hormone has in specific aspects of women's health, such as pregnancy and the ability to conceive. Well-designed clinical studies are needed to elucidate the necessary dose and the best form of treatment to resolve the very common calcifediol deficiency in women of reproductive age.

Relationship between Serum Vitamin D in Male, Sperm Function and Clinical Outcomes in Infertile Men Candidate for ICSI: A Cohort Study

Background

Today, vitamin D deficiency (VDD) is one of the major health issues around the world and VDD is associated with several diseases. This study was conducted to find the relationship between vitamin D status in male's serum with sperm function and clinical outcomes in infertile men candidate for intracytoplasmic sperm injection (ICSI).

Materials and Methods

In this cohort study, different parameters of male fertility such as sperm parameters, oxidative stress, and sperm chromatin status were evaluated in sperm samples of 30 infertile couples candidate for ICSI. Clinical outcomes like fertilization, embryo quality, and implantation were also assessed. Data were analyzed using SPSS Statistics 25.0 software. Besides, assessment of the correlation between aforementioned parameters with the level of serum vitamin D, in this study, ICSI candidates were divided into three groups [individuals with sufficient vitamin D levels (>30 ng/ml), insufficient vitamin D levels (between 20-29 ng/ml), and VDD (<20 ng/ml)]. The aforementioned parametesr were also compared between these study groups.

Results

Analysis of all the data revealed a significant correlation between the level of vitamin D with sperm concentration (P=0.000, r=0.5), sperm count (P=0.03, r=0.31) and sperm reactive oxygen species (ROS) level (P=0.000, r=-0.77). Moreover, comparing clinical outcomes within study groups showed a significant difference in implantation rate between sufficient and other groups (insufficient and deficient) (P=0.02).

Conclusion

Considering the association between sperm concentration and level of ROS with vitamin D and, higher implantation rate in individuals with vitamin D sufficient group compared to other two groups, our data call for vitamin D supplementation as part of male infertility treatment. But considering our sample size, further research is needed to verify these findings.

100 YEARS OF VITAMIN D: Effect of serum vitamin D level before ovarian stimulation on the cumulative live birth rate of women undergoing in vitro fertilization: a retrospective analysis

OBJECTIVE

Vitamin D receptors are present in the female reproductive tract. Studies on the association between serum vitamin D level and pregnancy rate of in vitro fertilization (IVF) showed inconsistent results and focused on a single fresh or frozen embryo transfer cycle. The objective of our study was to evaluate if serum vitamin D level before ovarian stimulation was associated with the cumulative live birth rate (CLBR) of the first IVF cycle.

DESIGN

Retrospective cohort study.

METHODS

Women who underwent the first IVF cycle from 2012 to 2016 at a university-affiliated reproductive medicine center were included. Archived serum samples taken before ovarian stimulation were analyzed for 25(OH)D levels using liquid chromatography-mass spectrometry.

RESULTS

In total, 1113 had pregnancy outcome from the completed IVF cycle. The median age (25th-75th percentile) of the women was 36 (34-38) years and serum 25(OH)D level was 53.4 (41.9-66.6) nmol/L. The prevalence of vitamin D deficiency (less than 50 nmol/L) was 42.2%. The CLBR in the vitamin D-deficient group was significantly lower compared to the non-deficient group (43.9%, 208/474 vs 50.9%, 325/639, P = 0.021, unadjusted), and after controlling for women's age, BMI, antral follicle count, type and duration of infertility. There were no differences in the clinical/ongoing pregnancy rate, live birth rate and miscarriage rate in the fresh cycle between the vitamin D deficient and non-deficient groups.

CONCLUSIONS

Vitamin D deficiency was prevalent in infertile women in subtropical Hong Kong. The CLBR of the first IVF cycle in the vitamin D-deficient group was significantly lower compared to the non-deficient group.

The Effects of Follicular Fluid 25(OH)D Concentration on Intrafollicular Estradiol Level, Oocyte Quality, and Fertilization Rate in Women Who Underwent IVF Program

Objective

25(OH)D (Vitamin D) has been investigated for its role in the process of folliculogenesis and thus affects the quality of oocyte produced by in vitro fertilization. Our aims were to investigate the effects of 25(OH)D levels in follicular fluid, follicular estradiol level, successful fertilization rate in IVF treatment and the correlation between 25(OH)D levels in follicular fluid with the oocyte quality.

Design and Setting

This is an analytic observational study with cross-sectional design conducted between September-November 2018 in two fertility clinics at tertiary hospitals in Bandung, Indonesia.

Participants

The inclusion criteria were women aged 20-35 years who underwent controlled ovarian stimulation in IVF program with normal ovarian reserve and normal BMI. Eligible women were divided into two groups based on their 25(OH)D levels: low and high.

Results

There was a significant difference in oocyte quality (p = 0.03) and follicular estradiol levels (p = 0.02) between the two categories of 25(OH)D levels. High level of 25(OH)D has significantly higher level in comparison with the low level of 25(OH)D. No significant differences were found in terms of successful fertilization rate (p = 0.13). High level of 25(OH)D has higher successful fertilization rate compared to low level of 25(OH)D (71.8% vs 55.26%). A significant positive correlation between 25(OH)D level in follicular fluid and oocyte quality was also found (r = 0.32, p = 0.01).

Conclusion

Women with higher level of 25(OH)D are significantly more likely to have high-quality oocyte and follicular estradiol levels than those with low level of 25(OH)D, although there are no significant results for its relation to successful fertilization rate.

Effects of vitamin D supplementation on ovarian reserve markers in infertile women with diminished ovarian reserve

The purpose of this study was to evaluate the effects of vitamin D supplementation on ovarian reserve markers, including serum anti-Mullerian hormone (AMH) level, follicle-stimulating hormone (FSH) level, and antral follicle count (AFC), in infertile women with diminished ovarian reserve and vitamin D deficiency.A prospective, nonrandomized, cross-sectional study was conducted. Women aged 18 to 41 years who were unable to become pregnant after 12 months of sexual intercourse and had normal tubal patency, partners with normal semen analysis, diminished ovarian reserve, and 25-hydroxyvitamin D [25(OH)D] deficiency were included. Eligible patients' AFC and serum levels of AMH, FSH, 25(OH)D, 1,25-dihydroxyvitamin D [1,25(OH)D], calcium, phosphate, alkaline phosphatase, and parathormone were assessed before and after administration of 300,000 IU of vitamin D ampules. Changes in the parameter values after vitamin D supplementation were compared with the initial levels.The study was conducted in 62 of the 142 participants. The AFC and AMH, 25(OH)D, 1,25(OH)D, phosphate (P < .01), and calcium levels (P < .05) were statistically significantly increased after vitamin D supplementation. Statistically significant decreases in FSH (P < .01) and alkaline phosphatase levels (P < .05) were observed after vitamin D supplementation. No statistically significant correlations were found between 25(OH)D level and AFC, 1,25(OH)D level, AMH level, and FSH level before and after supplementation (P > .05).As improvements in the ovarian reserve markers were obtained with vitamin D supplementation, vitamin D might be considered as a fertility treatment for patients with diminished ovarian reserve and vitamin D deficiency.

Thyroid autoimmunity and vitamin D: Effects on in vitro fertilization/intracytoplasmic sperm injection laboratory outcomes

This prospective cohort study aimed to determine the effects of thyroid autoimmunity, serum/follicular fluid vitamin D levels, and vitamin D receptor expression in granulosa cells on laboratory outcomes of in vitro fertilization/intracytoplasmic sperm injection. The study included 206 women with or without thyroid autoimmunity undergoing in vitro fertilization/intracytoplasmic sperm injection ovarian stimulation cycles. The primary outcomes in thyroid autoimmunity and non-thyroid autoimmunity patients with high or low follicular fluid vitamin D levels (high vitamin D level, ≥20 ng/mL; low vitamin D level, <20 ng/mL) were the number of oocytes retrieved and quality of embryos. The secondary outcomes were the association between serum and follicular fluid vitamin D levels and vitamin D receptor expression in granulosa cells. Our study revealed that thyroid autoimmunity was associated with fewer good-quality embryos but not oocytes (p = 0.010). The vitamin D level in the follicular fluid was significantly correlated with that in the serum (p < 0.001, r > 0.5). The study populations in the thyroid autoimmunity and non-thyroid autoimmunity groups were divided into two subgroups based on high/low serum/follicular fluid vitamin D levels. There was no significant difference in the number of retrieved oocytes and good-quality embryos between the subgroups with high or low vitamin D levels (p > 0.05), and the incidence of thyroid autoimmunity was comparable between the subgroups (p > 0.05). Linear regression analysis indicated that thyroid autoimmunity had a negative effect on the number of healthy embryos (p = 0.038). Reverse transcription-polymerase chain reaction results indicated that vitamin D receptor expression in granulosa cells was positively correlated with follicular vitamin D levels in the thyroid autoimmunity (p = 0.0002) and non-thyroid autoimmunity (p < 0.0001) groups. The current findings suggest that thyroid autoimmunity may have a more detrimental effect on in vitro fertilization/intracytoplasmic sperm injection laboratory outcomes than vitamin D.

Vitamin D and anti-Müllerian hormone concentration in human follicular fluid individually aspirated from all patient follicles

OBJECTIVE

The main aim of this prospective study was to investigate the relationship between intrafollicular vitamin D and anti-Müllerian hormone (AMH) concentration and its impact on oocyte quality and developmental competence.

METHODS

The analysis was performed on 208 follicular fluid (FF) samples obtained from 33 patients undergoing ovarian stimulation as part of in vitro fertilization (IVF) treatment that included intracytoplasmic sperm injection.

RESULTS

Our study shows that vitamin D concentration in FF varies according to the developmental stage of the oocyte and corelates with embryo development status on day 3, while AMH concentration in FF is not correlated with the developmental potential of an oocyte. We demonstrated that the levels of vitamin D and AMH were higher in FF than in serum. Moreover we showed that AMH and vitamin D levels were positively correlated in FF but not in serum.

CONCLUSION

FF-AMH levels do not appear to be a suitable as noninvasive test of the developmental potential of an oocyte, while FF-vitamin D level can be used to evaluate whether embryos obtained from particular oocytes have potential of reaching the third day of culture. However, our results encourage further research to be carried out on a larger number of patients and testing additional components found in FF such as androgens.

Effect of Vitamin D Supplementation on In Vitro Fertilization Outcomes: A Trial Sequential Meta-Analysis of 5 Randomized Controlled Trials

Despite numerous studies indicating an imperative role of vitamin D for reproduction, the importance of vitamin D supplementation on in vitro fertilization (IVF) outcomes remains controversial. We therefore performed this meta-analysis to investigate the IVF outcomes of vitamin D supplementation in infertile women with vitamin D deficiency. We systematically searched PubMed, Embase and the Cochrane library for identifying all relevant studies published before August 2021. Pregnancy rate was defined as the primary outcome while good quality embryo, fertilization rate, ongoing pregnancy, and miscarriage were secondary outcomes. We used Review Manager 5.3 (RevMan) to conduct meta-analysis and examined the robustness of the primary outcome by trial sequential analysis. Five studies were included in the final analysis and it suggested that vitamin D supplementation was associated with improved chemical pregnancy rate (risk ratio [RR] = 1.53, 95% confidence interval [CI] = 1.06 to 2.20, p = 0.02) but not benefited in improving clinical pregnancy rate (RR = 1.34, 95% CI = 0.81 to 2.24, p = 0.25) and all secondary outcomes. Trial sequential analysis suggested further studies are needed to confirm this conclusion. We concluded that vitamin D supplementation should be prescribed to improve chemical pregnancy in infertile women with vitamin D deficiency and more studies are required to further confirm this finding.

Insights into the perspective correlation between vitamin D and regulation of hormones: sex hormones and prolactin

Aim. Vitamin D is currently an exciting research target, besides its obvious role in calcium homeostasis and bone health, enormous work is being directed at examining the effects of this vitamin on various biological functions and pathological conditions.

Material and methods. The review of the literature and the analysis took about six months and was carried out through PubMed. This is a search engine opening mainly the MEDLINE database of trusted references. We called up all studies written in English that were published between the years 2004 to 2021 and that came through using the applied search terms, and analysed all those that met the criteria.

Results. The endocrine system with its many glands and hormones and their essential roles in the maintenance of normal body functioning cannot be far from interactions with vitamin D. Male and female sex hormones are no exceptions and many studies have investigated the correlations between these hormones and vitamin D. As such, direct and indirect relationships have been found between vitamin D, its receptors or one of its metabolising enzymes with sex hormones and the development of reproductive organs in males and females.

Conclusion. This review summarises the research investigating the associations of vitamin D with sex hormones and reproductive organs in males and females, and thus may pave the road for future studies that will investigate the clinical significance of vitamin D in the management of reproductive system disorders. Despite some conflicting results about the relationship between VD and the effectiveness of the reproductive system, many studies confirm the presence of receptors for this vitamin in the reproductive system, and this supports the direct or indirect relationship between VD and prolactin or VD and testosterone through PO4 and Ca2+ homeostasis, or production of osteocalcin. Therefore, VD is positively associated with semen quality and androgen status. Furthermore, a direct relationship between VD and the production of progesterone, estrogen and estrone in human ovarian cells has been supported by many studies.

The association between season, day length, and temperature on clinical outcomes after cryopreserved embryo transfer

OBJECTIVE

To investigate whether there is an association between season, temperature, and day length at oocyte retrieval and/or embryo transfer (ET) and clinical outcomes in frozen ET cycles.

DESIGN

Retrospective cohort study.

SETTING

Large academically affiliated research hospital.

PATIENT(S)

A total of 3,004 frozen ET cycles from 1,937 different women with oocyte retrieval and transfer between 2012 and 2017.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Implantation, clinical pregnancy, spontaneous abortion, and live birth.

RESULT(S)

Frozen ETs with oocyte retrieval dates in summer had 45% greater odds of clinical pregnancy (odds ratio [OR], 1.45; 95% confidence interval [CI], 1.15-1.82) and 42% greater odds of live birth (OR, 1.42; 95% CI, 1.13-1.79) compared with those with oocyte retrieval dates in winter. A 41% greater odds of clinical pregnancy (OR, 1.41; 95% CI, 1.16-1.71) and 34% greater odds of live birth (OR, 1.34; 95% CI, 1.10-1.62) were observed among transfers with an average temperature at oocyte retrieval in the highest tertile (17.2-33.3 °C) compared with those in the lowest tertile (-17.2-6.7 °C). There were no consistent associations between clinical outcomes and day length at oocyte retrieval or between season, day length, or temperature at transfer of thawed embryos.

CONCLUSION(S)

Warmer temperatures at oocyte retrieval are associated with higher odds of clinical pregnancy and live birth among frozen ET cycles. The consistent associations seen with oocyte retrieval dates and the lack of associations observed with ET dates suggest that any seasonality effects on in vitro fertilization success are related to ovarian function and not uterine receptivity.

Vitamin D modulates the transcription factors of T cell subsets to anti-inflammatory and regulatory profiles in preeclampsia

Vitamin D (VD) is a multifunctional prohormone and low VD status in pregnancy may contribute to the risk of adverse perinatal outcomes, such as preeclampsia (PE). This molecule may modulate the polarization of T cell subsets during gestation. This study evaluated the in vitro immunomodulatory effect of VD [1,25(OH)₂D₃] on the gene expression of transcription factors and on cytokine production by T cell subsets. Twenty pregnant women with PE and twenty normotensive (NT) pregnant women were studied. Plasma concentration of VD, [25(OH)D₃], was evaluated by chemiluminescence. PBMCs from preeclamptic and NT pregnant women were cultured in the absence or presence of VD to determine gene expression of T-bet (Th1), GATA-3 (Th2), RORγt, and RUNX1 (Th17), FoxP3 (regulatory T cell- Treg), and the receptors of VD (VDR) and IL-23 (IL-23R) by quantitative PCR. The concentration of cytokines in the PBMC supernatant culture was determined by cytometric bead array and ELISA immunoassay. The results showed that plasmatic levels of VD were significantly lower in the PE group. The treatment of PBMCs from PE pregnant women with VD induced downregulation of genes related to inflammatory profiles (Th1 and Th17), as well as an increase of the Th2 and Treg profiles. Thus, VD treatment decreased the release of IFN-γ, TNF-α, IL-17, IL-6, and IL-23 while it increased the levels of IL-10 in the PE group. VD induces an immunomodulatory effect in T cell subsets from pregnant women with PE, polarizing these cells to an anti-inflammatory and regulatory profile.

The Effects of Serum and Follicular Fluid Vitamin D Levels on Assisted Reproductive Techniques: A Prospective Cohort Study

BACKGROUND

Based on studies on animal models, vitamin D plays an essential role in reproduction by controlling Ca and Mg levels. Despite these findings, the effects of vitamin D deficiency and supplementation on the outcome of assisted reproductive techniques (ART) remain controversial. Therefore, the aim of the present study was to assess the relationship between serum and follicular fluid 25-OH vitamin D levels on reproductive outcomes of infertile women.

MATERIALS AND METHODS

This prospective cohort study included 150 infertile women who underwent in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). The participants were allocated to one of the three groups according to their serum and follicular fluid 25-OH vitamin D concentrations (less than 10 ng/ml, between 10 and 30 ng/ ml and more than 30 ng/ml), and fertilization, cleavage and biochemical and clinical pregnancy rates were compared among the groups. Data was analyzed by SPSS software and using Chi-square and Spearman correlation coefficient.

RESULTS

Serum and follicular fluid vitamin D levels significantly correlated with biochemical (P=0.008), (P=0.003) and clinical pregnancy (P=0.017), (P=0.001) rates respectively . However, the quality of embryos (P=0.125), (P=0.106) and fertilization rate (P=0.082), (P=0.059) were not associated with the level of serum and follicular fluid vitamin D.

CONCLUSION

This study found that women with higher levels of vitamin D in their serum and follicular fluid are significantly more likely to achieve pregnancy but without affecting the quality of embryo and fertility rate.

An increase of phosphatidylcholines in follicular fluid implies attenuation of embryo quality on day 3 post-fertilization

Background

Although oocyte quality is the dominant factor determining embryo quality, few studies have been conducted to evaluate embryo quality based on the metabolites related to the oocyte. With quantification of the follicular fluid (FF) metabolites, in assisted reproductive technology (ART), this study sought to evaluate the embryo or oocyte quality through an informative approach.

Results

An evaluation model consisting of 17 features was generated to distinguish the embryo quality on day 3 post-fertilization, and phosphatidylcholines (PCs) were the key contributors to the evaluation. The model was extended to the patients under different ages and hyperstimulations, and the features were further enriched to facilitate the evaluation of the embryo quality. The metabolites were clustered through pathway analysis, leading to a hypothesis that accumulation of arachidonic acid induced by PCs might weaken embryo quality on day 3 post-fertilization.

Conclusions

A discriminating model with metabolic features elicited from follicular fluid was established, which enabled the evaluation of the embryo or oocyte quality even under certain clinical conditions, and the increase of PCs in follicular fluid implies the attenuation of embryo quality on day 3 post-fertilization.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12915-021-01118-w.

Low vitamin D levels in follicular fluid, but not in serum, are associated with adverse outcomes in assisted reproduction

PURPOSE

To assess the relationship between serum/follicular fluid (FF) vitamin D (VD) status and assisted reproductive technology (ART) treatment outcomes among infertile patients.

METHODS

A prospective cohort study, including 132 infertile patients scheduled for their first ART treatment cycle, was carried out in a Reproductive Medical Center. Serum and FF samples were collected to assess 25-hydroxy VD [25(OH)D] levels. Low VD level was defined as 25(OH)D concentration of less than 30 ng/mL.

RESULTS

Most infertile patients had low VD levels in serum (88%) and FF (90%). We observed a moderately positive correlation between VD levels in serum and FF (r = 0.34, p < 0.0001). Compared to the group of patients with low VD levels in the FF, those with sufficient VD levels had a significantly higher number of retrieved oocytes (p = 0.03), normal fertilization (p = 0.01), and high-quality embryos (p = 0.001). Moreover, patients with sufficient VD levels in the FF also had significantly higher implantation rates than those with low VD levels (76.92% vs. 46.58%, respectively, p = 0.01) and clinical pregnancy rates (92.31% vs. 61.54%, respectively, p = 0.04).

CONCLUSION

These data collectively revealed that low VD levels in serum and FF were common among infertile patients. VD levels in FF, but not in serum, were associated with embryo quality, normal fertilization, implantation rates, and clinical pregnancy rates. Further studies are mandatory to determine the molecular mechanism and VD's potential therapeutic benefits in infertile patients.

The effect of vitamin D supplementation on clinical symptoms and metabolic profiles in patients with endometriosis

BACKGROUND

To our knowledge, data on the effects of vitamin D supplementation on clinical symptoms and metabolic profiles in patients with endometriosis are limited. This study was conducted to determine the effects of vitamin D supplementation on clinical symptoms and metabolic profiles in patients with endometriosis.

METHODS

The current randomized, double-blind, placebo-controlled trial was conducted among 60 patients (aged 18-40 years old) with endometriosis. Participants were randomly allocated into two groups (30 participants each group) to receive either 50,000 IU vitamin D or placebo each 2 weeks for 12 weeks.

RESULTS

Vitamin D supplementation significantly decreased pelvic pain (β - 1.12; 95% CI, -2.1, -0.09; p=.03) and total-/HDL-cholesterol ratio (β - 0.29; 95% CI, -0.57, -0.008; p=.04) compared with the placebo. Moreover, vitamin D intake led to a significant reduction in high-sensitivity C-reactive protein (hs-CRP) (β - 0.64 mg/L; 95% CI, -0.97, -0.30; p<.001) and a significant increase in total antioxidant capacity (TAC) (β 47.54 mmol/L; 95% CI, 19.98, 75.11; p=.001) compared with the placebo.

CONCLUSIONS

Overall, our study demonstrated that vitamin D intake in patients with endometriosis resulted in a significant improvement of pelvic pain, total-/HDL-cholesterol ratio, hs-CRP and TAC levels, but did not affect other clinical symptoms and metabolic profiles.

Oral Vitamin D supplementation impacts gene expression in granulosa cells in women undergoing IVF

STUDY QUESTION

Does oral Vitamin D supplementation alter the hormonal milieu of follicular fluid (FF) and the transcriptomic profile of luteinised granulosa cells (GCs) in women with Vitamin D deficiency undergoing IVF?

SUMMARY ANSWER

A transcriptomic signature relevant to oral Vitamin D supplementation in luteinised GCs was demonstrated, although Vitamin D supplementation did not alter hormone levels in FF.

WHAT IS KNOWN ALREADY

Vitamin D deficiency is linked to lower live birth rates among women undergoing IVF. It is unclear whether Vitamin D elicits a targeted action in reproductive physiology or is a surrogate marker of overall well-being. Several in-vitro studies, but none in vivo, have examined the impact of Vitamin D on the periovulatory follicle, focusing on GCs as a proxy marker of oocyte competence.

STUDY DESIGN, SIZE, DURATION

We present a report of secondary outcomes from the SUNDRO clinical trial, which was launched in 2016 to determine whether Vitamin D supplementation can improve the IVF outcomes of women who are deficient in Vitamin D (<30 ng/ml). FF samples of 145 women who were randomised to receive Vitamin D or placebo from March 2017 to January 2019 were collected. All follicles that were aspirated in our study measured ≥11 mm on the day of hCG trigger. The first cohort of samples was collected from the dominant follicle of each participant and utilised for hormone profiling (n = 50 Vitamin D, n = 45 Placebo). For the second cohort, the follicle aspirates of each participant were pooled to create a single FF sample, which was used for the isolation of GCs for gene expression studies (n = 20 Vitamin D, n = 30 placebo). Six of the samples from the second cohort were used for RNA-sequencing analysis (n = 3 Vitamin D, n = 3 placebo).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Two academic infertility units were involved in the recruitment of the participants, who received a single dose of oral 25-hydroxyvitamin D (600 000 IU) or placebo, 2-12 weeks before oocyte retrieval. Women in both groups were deficient in Vitamin D, aged 18-39 years with a normal BMI (18-25 kg/m2) and <3 previous IVF cycles. The FF was aspirated at the time of oocyte retrieval and stored. Liquid chromatography tandem mass spectrometry was used to measure FF abundance of 25-hydroxyvitamin D, aldosterone, androstenedione, cortisol, cortisone, corticosterone, 11-deoxycorticosterone, 11-deoxycortisol, 21-deoxycortisol, dehydroepiandrosterone, dehydroepiandrosterone sulfate, dihydrotestosterone, oestradiol (E2), 17-OH-hydroxyprogesterone, progesterone (P4) and testosterone. GCs were isolated from pooled FFs and the transcriptome was evaluated by RNA-sequencing and RT-PCR. Ingenuity pathway analysis (IPA) was used to assess the top canonical pathways and upstream regulators mediating the action of Vitamin D.

MAIN RESULTS AND THE ROLE OF CHANCE

At oocyte retrieval, FF concentration of 25-hydroxyvitamin D was 2.8-fold higher (P < 0.001) in the Vitamin D group (39.5 ng/ml; n = 50) compared to placebo (13.8 ng/ml; n = 45) but no other hormonal differences were detected. In the placebo group, but not the Vitamin D group, weak correlations of 25-hydroxyvitamin D concentration with P4 (r = 0.31, P = 0.03) and E2 (r = 0.45, P = 0.002) were observed. RNA-sequencing identified 44 differentially expressed genes in the GCs of patients who received Vitamin D (n = 3) compared to placebo (n = 3). RT-PCR demonstrated upregulation of VDR (vitamin D receptor), GSTA3 (glutathione S-transferase A3) and IL21R (interleukin 21 receptor), and downregulation of P T GS2 (prostaglandin-endoperoxide synthase 2), KLF4 (kruppel-like factor 4), T RP C4 (transient receptor potential cation channel subfamily C member 4), VEGF (vascular endothelial growth factor), RXRB (retinoid X receptor beta) and AGER (advanced glycosylation end-product specific receptor) genes in the Vitamin D (n = 17) versus placebo (n = 27) group. IPA suggested roles of Vitamin D in antioxidant defence.

LIMITATIONS, REASONS FOR CAUTION

Interpretation of the data is influenced by our intervention strategy (2-12 weeks prior to retrieval). As folliculogenesis may last 5-6 months, our protocol can only examine with confidence the impact of Vitamin D on the final stages of follicular growth. Furthermore, we examined the hormonal profile of the dominant follicle only, while the GC data reflect the transcriptome of all (pooled) follicles large enough to be used for IVF. Luteinised GCs from controlled ovarian stimulation were used in this study, which may be functionally distinct from the GCs of developing follicles. Moreover, the sample size for RNA-sequencing analysis was low (n = 3 per group), regardless of validation by RT-PCR that was performed on a larger cohort, introducing complexity to the IPA analysis, which required an input of data with P-adjusted <0.08 instead of <0.05 to be informative.

WIDER IMPLICATIONS OF THE FINDINGS

This is the first in-vivo study to show that Vitamin D supplementation alters gene expression in luteinised GCs. In contrast to some in-vitro evidence, no effect of the intervention on expression of genes encoding steroidogenic enzymes was observed. Unlike other studies, our results suggest that supplementation with Vitamin D is unlikely to directly influence hormone availability in FF. Our findings instead reinforce the hypothesis that Vitamin D could be considered one of the gatekeepers in protecting against an exaggerated response to ovarian stimulation.

STUDY FUNDING/COMPETING INTEREST(S)

The study has been funded by the Italian Ministry of Health (RF-2013-02358757) following peer review in the competitive 'Bando di Ricerca Finalizzata e Giovani Ricercatori 2013' for the clinical trial SUNDRO (EudraCT registration number 2015-004233-27). There are no competing interests.

TRIAL REGISTRATION NUMBER

EudraCT registration number 2015-004233-27.

Positive effect of a new supplementation of vitamin D3 with myo-inositol, folic acid and melatonin on IVF outcomes: a prospective randomized and controlled pilot study

To assess whether oral supplementation of vitamin D₃, myo-inositol, folic acid and melatonin affects IVF outcomes. One hundred and twenty consecutive infertile women attending IVF treatment were 1:1 randomly distributed in two groups. Women in group A (control) were assigned to receive myo-inositol, alpha-lactalbumin and folic acid in the morning, and myo-inositol, folic acid and melatonin in the evening. Women in group B (treated) were assigned to receive analogous treatment, with the addition of cholecalciferol (vitamin D₃) in the evening from the early beginning of the luteal phase. 50 patients in group A and 50 in group B underwent blastocyst transfer and were considered in the statistical analysis. Vitamin D₃ levels significantly increased after 45 days of treatment: 33.2 ng/ml in group B Vs. 24.3 ng/ml in group A (p < .0001). The implantation rate increased as well: 37.1% in group B Vs. 19.2% in group A (p < .0151). Overall, the results indicate that increased vitamin D₃ levels positively correlate with the implantation rate in IVF. Because of the low number of participants, these findings need to be confirmed with larger cohorts of patients.

Vitamin D Status Impacts Genital Mucosal Immunity and Markers of HIV-1 Susceptibility in Women

While vitamin D insufficiency is known to impact a multitude of health outcomes, including HIV-1, little is known about the role of vitamin D-mediated immune regulation in the female reproductive tract (FRT). We performed a pilot clinical study of 20 women with circulating 25(OH)D levels <62.5 nmol/L. Participants were randomized into either weekly or daily high-dose oral vitamin D supplementation groups. In addition to serum vitamin D levels, genital mucosal endpoints, including soluble mediators, immune cell populations, gene expression, and ex vivo HIV-1 infection, were assessed. While systemic vitamin D levels showed a significant increase following supplementation, these changes translated into modest effects on the cervicovaginal factors studied. Paradoxically, post-supplementation vitamin D levels were decreased in cervicovaginal fluids. Given the strong correlation between vitamin D status and HIV-1 infection and the widespread nature of vitamin D deficiency, further understanding of the role of vitamin D immunoregulation in the female reproductive tract is important.

Impact of vitamin D on human embryo implantation-a prospective cohort study in women undergoing fresh embryo transfer

OBJECTIVE

To measure free and total 25-hydroxyvitamin D [25(OH)D] immediately before embryo transfer and analyze its association with early pregnancy outcome parameters such as biochemical pregnancy, implantation rate, and clinical pregnancy rates in women undergoing fresh embryo transfer after their first ovarian hyperstimulation.

DESIGN

Prospective cohort study.

SETTING

Academically affiliated private fertility center.

PATIENT(S)

A total of 2,569 women undergoing fresh embryo transfer after ovarian hyperstimulation.

INTERVENTIONS(S)

None.

MAIN OUTCOME MEASURE(S)

The study end points were biochemical pregnancy rate, implantation rate, clinical pregnancy rate, ectopic pregnancy rate, early miscarriages, and ongoing pregnancy rate. Free and total 25(OH)D concentrations were measured 1 day before embryo transfer.

RESULT(S)

Total 25(OH)D correlated with free 25(OH)D. Total and free 25(OH)D serum concentrations were similar in those patients reaching and not reaching the study outcomes (biochemical pregnancy rate, implantation rate, clinical pregnancy rate, ectopic pregnancy rate, early miscarriages, and ongoing pregnancy rate). There was likewise no statistical difference when analyzing the frequency of all study outcomes in quintiles of either total or free 25(OH)D. In addition, the study population was divided into three groups according to the total vitamin D status based on clinical practice guideline. All outcomes were similar in women with adequate, insufficient, and deficient total 25(OH)D. Multiple linear regression analysis considering confounding likewise indicated no association of free or total vitamin D with any of the study outcomes.

CONCLUSION(S)

Neither free nor total 25(OH)D concentration at embryo transfer was associated with successful embryo implantation in women undergoing fresh transfer after ovarian hyperstimulation.

How vitamin D level influences in vitro fertilization outcomes: results of a systematic review and meta-analysis

OBJECTIVE

To investigate the impact of serum vitamin D level on in vitro fertilization (IVF) outcomes.

DESIGN

Systematic review and meta-analysis.

SETTING

Not applicable.

PATIENTS

Infertile women undergoing conventional IVF or intracytoplasmic sperm injection (ICSI).

INTERVENTIONS

Systematic search of PubMed, MEDLINE, EMBASE, Global Health, The Cochrane Library, Health Technology Assessment Database, and Web of Science from inception until July 2019 with cross-checking of references from relevant articles in English. Vitamin D levels were categorized into three groups: deficient (<20 ng/mL), insufficient (20-30 ng/mL), and replete (>30 ng/mL). Before starting the data extraction, we registered the review protocol in PROSPERO (CRD42019134258).

MAIN OUTCOME MEASURES

We consider clinical pregnancy rate (CPR), live birth rate (LBR), and/or ongoing pregnancy rate (OPR) as primary outcomes. Likewise, the miscarriage rate was considered as a secondary outcome.

RESULTS

Primary analysis showed that women with a replete level of vitamin D had higher CPR and LBR/OPR compared to those with a deficient of insufficient level of vitamin D. However, sensitivity analysis led to non-significant differences between the comparators for CPR (odds ratio 0.71, 95% confidence interval 0.47-1.08, I2 = 61%) and OPR/LBR (odds ratio 0.78, 95% confidence interval 0.56-1.08], I2 = 61%). Also, for miscarriage a statistically different rate was not reached.

CONCLUSION

Serum vitamin D levels do not influence IVF outcomes in terms of CPR, LBR/OPR, and miscarriage rate. Future large cohort studies are warranted to determine whether the threshold of vitamin D affects reproductive outcomes. Currently, there is a lack of consensus between the appropriate vitamin D threshold to predict reproductive outcomes compared to the one established for bone health.

PROSPERO NUMBER

CRD42019134258.

Calcitriol Effect on Outcomes of in Vitro Fertilization in Infertile Women with Vitamin D Deficiency: A Double-Blind Randomized Clinical Trial

INTRODUCTION

Recent studies have addressed the role of micronutrients in fertilization, such as vitamin D. The present study aims to explore the effects of using calcitriol, an active form of vitamin D, on IVF results in women with vitamin D deficiency.

METHOD

This double-blinded randomized clinical trial was done on 180 infertile women, undergone IVF treatment. Out of them, 95 were found to have vitamin D deficiency (blood serum 25-dihydroxy vitamin D <30 ng/ml). Fifty one women in experimental group were treated with two 0.25 µg calcitriol pills daily during 4 weeks (discontinued 8 hours prior to the embryo transfer) and 44 subjects to the placebo group (mean vitamin D deficiency 27.5 ±1.8 in case group vs. 27.6±1.8 in control group, P>0.05). Final analysis includes outcomes of chemical and clinical pregnancy was done on 74 women (including 36 in case and 38 in control group).

RESULTS

Our study showed that in the experimental group, chemical pregnancy success was significantly higher than that in the control group, 31.4 vs. 18.2% (P<0.05). However, there were no significant differences between the 2 groups in reaching the clinical pregnancy stage (25.5% in case group vs. 13.6% in control group) and continuation of pregnancy into week 20 (9.8% in case group vs. 11.6% in control group) (P>0.05).

CONCLUSION

Calcitriol administration by improving the implantation process can significantly increase the chances of successful IVF cycle results in infertile women with vitamin D deficiency.

Association between Vitamin D Levels and Fertility Outcomes in Patients Undergoing IVF/ICSI

Background: Several studies have demonstrated that vitamin D (vitD) might play an important role in the reproductive system due to expression of vitD receptor and vitD-metabolizing enzymes in many reproductive tissues. VitD deficiency has been associated with increased risk of obstetric complications. However, the effect of vitD levels on in vitro fertilization (IVF)/ICSI outcomes is not fully understood. Evidence shows that women with adequate vitD levels might have higher pregnancy rates. This study evaluated the association between serum vitD levels and IVF/ICSI outcomes.

Methods: This multicenter, retrospective cohort study was conducted at IVFMD, My Duc Hospital and IVFMDPN, My Duc Phu Nhuan Hospital, Ho Chi Minh City, Vietnam between November 2017 and July 2019. Vietnamese patients aged 18–40 years with serum vitD (25(OH)D) samples collected before starting controlled ovarian stimulation and undergoing embryo transfer were eligible. Patients were divided into four groups based on 25(OH)D levels: <10 ng/mL, 10 to <20 ng/mL, 20 to <30 ng/mL, and [Formula: see text]30 ng/mL. The primary outcome was ongoing pregnancy rate.

Results: Of 3779 patients recruited, 25(OH)D levels were <10 ng/mL in 564 (14.9%), 10 to <20 ng/mL in 436 (11.5%), 20 to <30 in 1,142 (30.2%), and [Formula: see text]30 ng/mL in 1,637 (43.3%). Ongoing pregnancy rates were similar across the four subgroups (36%, 40%, 36%, and 36%, respectively; p = 0.409). The number of oocytes retrieved, embryos, clinical pregnancy, implantation, and miscarriage rates did not differ significantly between subgroups.

Conclusions: In this analysis, serum vitD levels did not appear to be correlated with pregnancy outcomes in patients undergoing IVF/ICSI.

Obesity, Insulin Resistance, and Hyperandrogenism Mediate the Link between Poor Diet Quality and Ovarian Dysmorphology in Reproductive-Aged Women

The relationship between diet quality and ovarian morphology has biological plausibility yet remains unclear and was therefore evaluated. In a multicenter cross-sectional analysis, four dietary patterns were scored for 111 consecutive reproductive-aged women (18-45 years) using (1) Healthy Eating Index (HEI-2015); (2) alternative HEI-2010; (3) alternate Mediterranean Diet (aMED); (4) and Dietary Approaches to Stop Hypertension (DASH) indices. Ovarian volume (OV) and follicle number per ovary (FNPO) were evaluated on transvaginal ultrasonography. Relationships between dietary and ovarian morphology indices were evaluated by linear regression and mediation analyses. Associations between aMED and DASH scores and OV/FNPO were completely mediated by obesity, insulin resistance, and hyperandrogenism (All: p < 0.05), unlike direct associations (All: p ≥ 0.89). Namely, a 1-standard deviation [SD] increase in aMED score was associated with decreases in OV (0.09 SD; 0.4 mL) through reducing waist circumference. Likewise, a 1 SD increase in aMED and DASH score was associated with decreases in OV (0.07 SD; 0.3 mL) by reducing glucose response to a 75 g glucose tolerance test. A 1 SD increase in DASH score was associated with decreased FNPO (0.07 SD; 2 follicles) by reducing free androgen index (All: p < 0.05). Adherence to aMED and DASH eating plans was indirectly associated with significant improvements in ovarian form, providing novel mechanistic insights for future interventions about contributions of diet quality on ovarian function.

Relation of serum vitamin D level in polycystic ovarian syndrome (PCOS) patients to ICSI outcome

Background

Recently, vitamin D was discovered to have an important role in female reproduction and IVF. However, there were no studies specifically addressed its role in polycystic ovarian syndrome (PCOS) patients undergoing ICSI cycles. Therefore, this cross-sectional study in a university hospital was conducted to evaluate the effect of serum level of vitamin D (VD) on the number of retrieved and fertilized oocytes, and chemical and clinical pregnancy rate in PCOS females undergoing ICSI cycles. The study included 80 PCOS cases undergoing ICSI cycles in the age from 20 to 39 years using antagonist protocol. Cases with severe male or tubal factors were excluded. Serum 25 (OH) D vitamin level was assessed by the ELIZA method on the day of oocyte retrieval. Correlation and regression analyses were used in the analysis.

Results

VD was positively correlated to both numbers of retrieved and fertilized oocytes (r = 0.35, 95% CI 0.15, 0.53, P = 0.001; r = 0.33; 95% CI 0.03, 0.57, P = 0.03, respectively). It was still significantly correlated to the number of oocytes (coefficient 0.47; 95% CI 0.1, 0.9; P = 0.018) and to the number of fertilized eggs (coefficient 0.3; 95% CI 0.02, 0.58; P = 0.03) after adjusting for age, BMI, and type of ovulation-triggering agent. This means with each 2 ng/mL increase in serum VD level, around one more egg will be retrieved. In addition, there will be one more fertilized oocyte with each 3 ng/mL increase in the vitamin level. However, no significant correlation was found between the vitamin level and the occurrence of chemical or clinical pregnancy.

Conclusions

Serum vitamin D level is positively correlated with the number of retrieved and fertilized oocytes in PCOS patients undergoing ICSI cycles.

Normal fertilisation rates and serum 25-OHD levels among couples undergoing in-vitro fertilisation: a prospective cohort study

Background

The aim of this study was to explore the correlation between serum vitamin D levels in couples undergoing in-vitro fertilisation (IVF) and normal fertilisation process.

Methods

Between March 2016 and March 2017, we performed a prospective cohort study at an academic reproductive medicine centre to measure serum 25-hydroxyvitaminD (25-OHD) levels of 1232 couples before controlled ovarian stimulation. Generalized linear regression and binary multivariate logistic regression were employed to assess whether 25-OHD levels in men and women correlated with normal fertilisation rates and low fertilisation rate (LFR).

Results

Serum 25-OHD levels in women were classified into three groups: Group A, less than 10%; Group B, between 10 and 90%; and Group C, greater than 90%. Using generalized linear regression, we observed that female 25-OHD levels were related to normal fertilisation rates. Adjusted normal fertilisation rates from Group A to Group C in women were 59.50, 62.72, and 66.13%, respectively (P = 0.007). After binary logistic regression analysis, for women, compared with Group C, the ORs for LFR were 4.814 in Group A (95% CI, 1.266–18.309, P = 0.021) and were 3.204 in Group B (95% CI, 0.949–10.812, P = 0.061). Male 25-OHD levels were not related to the probability of low fertilisation rate (P > 0.05).

Conclusions

Circulating 25-OHD concentrations in women appear to be associated with normal fertilisation rates and low fertilisation rates in IVF cycles, but not in men. A further randomized controlled trial with vitamin D supplementation is needed to demonstrate whether female vitamin D levels exert an effect on the normal fertilisation process.

Trial registration

https://clinicaltrials.gov/;NCT03305510; Registered 08 October 2017 - Retrospectively registered.

Estradiol and Progesterone Levels are Related to Redox Status in the Follicular Fluid During in vitro Fertilization

Studies have reported a possible association between the levels of oxidative stress biomarkers in follicular fluid (FF) and infertility treatment outcomes. FF analysis can provide important information about oocyte quality. This study aimed to evaluate the possible correlation between oxidative stress biomarker and intrafollicular hormone levels and clinical and laboratory parameters in women during controlled ovarian stimulation. These women were undergoing in vitro fertilization with intracytoplasmic sperm injection (ICSI).The FF samples were acquired from September 2012 to February 2014 from women undergoing private fertility treatment in Rio de Janeiro, Brazil. A total of 196 women who were undergoing ICSI and had different infertility diagnoses were recruited. The FF from each patient (average patient age of 36.3 ± 4.3 years) was collected following puncture of just one follicle with the largest diameter. After ruling out blood contamination by spectrophotometry, 163 patient samples were utilized in the study. In the FF, the progesterone levels were negatively correlated with (a) hydrogen peroxide scavenging capacity (HPSC) (r = −0.294, P < 0.0001), (b) total number of follicles (r = −0.246, P < 0.001) and (c) total number of oocytes punctured (r = −0.268, P = 0.0001). The concentration of serum estradiol exhibited a positive correlation with intrafollicular HPSC (r = 0.165, P = 0.037). Our data indicate that the FF levels of estradiol and progesterone are related to the FF redox status, which is closely associated with the number of oocytes obtained during ICSI procedures.

Association between vitamin D and endometriosis: a systematic review

BACKGROUND

Endometriosis is one of the most common gynecological diseases of reproductive age, with a prevalence of 5-10% and grave consequences for quality of life and fertility. Vitamin D (vit D), a classic regulator of plasma calcium concentration and skeleton mineralization, is also an effective modulator of the immune system. Several studies suggest that immunologic properties attributed to vit D along with vit D receptor (VDR) expression in reproductive tissues may be involved in the pathogenesis of endometriosis.

OBJECTIVE

To systematically review the literature for the association between components of vit D metabolism and endometriosis.

MATERIALS AND METHODS

A systematic review of the literature published in the Medline and Cochrane Central databases was conducted for original research articles on humans, published in any language.

RESULTS

Twenty-one studies were included in the systematic review. Among them, 12 examined the relationship of endometriosis with vit D metabolites, eight with vit D-binding protein (VDBP), three with VDR polymorphisms, and two with vit D regulatory enzymes. There are discrepancies between the outcomes of the available literature publications.

CONCLUSIONS

This is a systematic attempt to collect, evaluate, and present the known data on the association between vit D and endometriosis. Given the heterogeneity and the diversity of the present studies, more research is required to elucidate the association between vit D and endometriosis.

Vitamin D-Binding Protein in Pregnancy and Reproductive Health

Vitamin D-binding protein (VDBP), the main carrier of vitamin D, has recently been implicated in reproductive health and pregnancy outcomes including endometriosis, polycystic ovary syndrome (PCOS), pre-eclampsia, and gestational diabetes mellitus (GDM). Improved methods for measuring VDBP and an increased understanding of its role in biological processes have led to a number of newly published studies exploring VDBP in the context of pregnancy. Here, we synthesize the available evidence regarding the role of VDBP in reproductive health and pregnancy, and we highlight areas requiring further study. Overall, low levels of maternal serum VDBP concentrations have been associated with infertility, endometriosis, PCOS and spontaneous miscarriage, as well as adverse pregnancy outcomes including GDM, pre-eclampsia, preterm birth and fetal growth restriction. However, increased VDBP concentration in cervicovaginal fluid has been linked to unexplained recurrent pregnancy loss and premature rupture of membranes. Some genetic variants of VDBP have also been associated with these adverse outcomes. Further studies using more accurate VDBP assays and accounting for ethnic variation and potential confounders are needed to clarify whether VDBP is associated with reproductive health and pregnancy outcomes, and the mechanisms underlying these relationships.

Vitamin D Effects on the Immune System from Periconception through Pregnancy

Vitamin D is a well-known secosteroid and guardian of bone health and calcium homeostasis. Studies on its role in immunomodulatory functions have expanded its field in recent years. In addition to its impact on human physiology, vitamin D influences the differentiation and proliferation of immune system modulators, interleukin expression and antimicrobial responses. Furthermore, it has been shown that vitamin D is synthesized in female reproductive tissues and, by modulating the immune system, affects the periconception period and reproductive outcomes. B cells, T cells, macrophages and dendritic cells can all synthesize active vitamin D and are involved in processes which occur from fertilization, implantation and maintenance of pregnancy. Components of vitamin D synthesis are expressed in the ovary, decidua, endometrium and placenta. An inadequate vitamin D level has been associated with recurrent implantation failure and pregnancy loss and is associated with pregnancy-related disorders like preeclampsia. This paper reviews the most important data on immunomodulatory vitamin D effects in relation to the immune system from periconception to pregnancy and provides an insight into the possible consequences of vitamin D deficiency before and during pregnancy.

The effect of vitamin D status on ovarian reserve markers in infertile women: A prospective cross-sectional study

Background

Vitamin D deficiency and infertility are two important health problems in Iran. Some studies suggest that vitamin D may influence Anti-Müllerian hormone (AMH) and antral follicle count (AFC) as an ovarian reserve.

Objective

The present study aimed to investigate the impact of vitamin D on AMH serum concentrations/AFC.

Materials and Methods

Three hundred and five infertile women referred to the IVF Unit of Yas hospital, between July and December 2017, were enrolled in this cross-sectional study. The demographic characteristics of the participants, as well as the serum levels of vitamin D, AMH, and ultrasonic examination of AFC were recorded.

Results

Finally, 287 infertile women were included in the analysis with a mean age of 29.95 ± 4.73 yr (18-45 yr) and a mean Body mass indexof 25.11 ± 4.41 kg/m 2 . The median AMH and vitamin D levels were 3.20 and 22.82 ng/ml, respectively. Considering the cut-off level of 20 ng/ml, 58.7% were vitamin D deficient. Regression analysis showed no association between AMH and vitamin D levels (p = 0.161), even after adjusting for baseline variables (p = 0.182). A total of 120 patients had an AFC < 6 and 164 ≥ 6, which was not statistically different between the groups with normal level or deficient vitamin D (p = 0.133).

Conclusion

The present cross-sectional study showed no significant association between serum levels of vitamin D and AMH or AFC in infertile women, even after adjusting for baseline variables.

Follicular fat-soluble vitamins as markers of oocyte competency

The main aim of this prospective study was to investigate the effect of the concentration of fat-soluble vitamins A, D, E and K in individual follicles on oocyte quality and developmental competence. The analysis was performed on 313 follicular fluid (FF) samples from 50 patients undergoing ovarian stimulation with intracytoplasmic sperm injection. We demonstrated that the mean concentration of individual vitamins in FF correlated with their level in serum (p < 0.0001). The levels of vitamin D in FF were higher than in serum, while the opposite was observed for other analyzed vitamins. We did not observe a correlation between FF vitamin D concentration with fertilization success. However, we observed its association with embryo development status on day 3. Moreover, we showed a statistically significant negative correlation between the mean day 5 embryo score and the concentration of vitamin D in serum (rS = -0.68 p = 0.01) and follicular fluid (rS = -0.71 p = 0.01). Our study showed that FF concentration of vitamin A and E was helpful in the prediction of fertilization success of each individual oocyte. Moreover, vitamin A and E concentrations in FF were associated with status of embryo development on the third day of culture. Vitamin A was also associated with the embryo quality on day 2 and the embryo development status on day 5 after fertilization. In conclusion, a combination of FF vitamin analysis and routine morphological assessment could allow for a more accurate and sensitive method of determining embryonic developmental competence and enable the selection of a better embryo to transfer and perhaps translating into an increased chance of pregnancy.Abbreviations: in vitro fertilization: IVF; anti-Mullerian hormone: AMH; follicular fluid: FF; intracytoplasmic sperm injection: ICSI; top quality: TQ; vitamin D binding globulin level: VDBP; assisted reproductive technology: ART.

Vitamin D in Follicular Fluid Correlates With the Euploid Status of Blastocysts in a Vitamin D Deficient Population

CONTEXT

The widespread distribution of the Vitamin D (VitD) receptor in reproductive tissues suggests an important role for VitD in human reproduction. The assessment of patient´s VitD is based on the 25-hydroxyvitamin D (25(OH)D) metabolite measurement. However, most of the circulating 25(OH)D is bound to either VitD-binding protein (VDBP) (88%) or albumin (12%) and less than 1% circulates free.

OBJECTIVE

To determine a possible correlation between VitD levels in serum (S) and follicular fluid (FF) and blastocyst ploidy status in patients undergoing infertility treatment.

METHODS

A prospective observational study was performed including couples planned for preimplantation genetic testing for aneuploidies (PGT-A) from ART Fertility Clinics. Patients were classified according to their 25(OH)D-Serum levels: VitD deficient group <20 ng/ml and insufficient/replete ≥20 ng/ml defined as VitD non-deficient group.

RESULTS

Serum samples and 226 FF from individual follicles were collected for 25(OH)D, bioavailable 25(OH)D, free 25(OH)D, and % free 25(OH)D measurement. 25(OH)D-Serum in VitD deficient and non-deficient were 13.2±4.0 ng/ml vs 32.3±9.2 ng/ml; p<0.001. FF from 40 and 74 biopsied blastocysts was analysed of which 52.5 and 60.8% were euploid (p = 0.428), respectively. In VitD deficient patients, mean 25(OH)D-FF, bioavailable 25(OH)D-FF, and free 25(OH)D-FF were higher in euploid vs aneuploid blastocysts (18.3±6.3 ng/ml vs 13.9±4.8 ng/ml; p = 0.040; 1.5±0.5 ng/ml vs 1.1±0.4 ng/ml; p = 0.015; 0.005±0.002 ng/ml vs 0.003±0.001 ng/ml; p = 0.023, respectively), whilst no differences were found in VitD non-deficient patients (37.9±12.3 ng/ml vs 40.6±13.7 ng/ml; p = 0.380; 3.1±1.1 ng/ml vs 3.3±1.2 ng/ml; p = 0.323; 0.01±0.003 ng/ml vs 0.01±0.004 ng/ml; p = 0.319, respectively).

CONCLUSION

VitD non-deficient patients have a significantly higher probability of obtaining a euploid blastocyst compared to VitD deficient patients (OR:33.36, p = 0.002).

Controversies related to vitamin D deficiency effect on the maternal and feto-placental unit - an update

Vitamin D deficiency (Vit D deficiency) is a global health concern and a common occurrence especially among pregnant women. It has been suggested that Vit D deficiency has implications on both the mother and the foetus. Vitamin D deficiency is the most under-diagnosed nutritional deficiency in the world, affecting the majority of individuals, irrespective of their geography, gender, age or race. Vitamin D deficiency is also linked with several diseases (autoimmune diseases, cancer, cardiovascular, dementia and musculoskeletal diseases). Therefore, appropriate supplementation is required in a deficient population. A diagnosis can be missed as symptoms associated with pregnancy are also seen in vitamin D-deficient women. A timely diagnosis and treatment can be beneficial as these disorders can cause maternal and foetal morbidity. Vitamin D status during pregnancy has been associated with maternal and foetal morbidity, but reported findings are inconsistent.

Effect of vitamin D status on normal fertilization rate following in vitro fertilization

BACKGROUND

Vitamin D plays critical role in the female reproductive system. It seems that vitamin D is associated with clinical pregnancy outcomes of assisted reproductive technologies (ART), but its role remains elusive. This study is aimed to establish whether vitamin D is associated with clinical outcomes of in vitro fertilization (IVF).

METHODS

The cross-sectional study was carried out from January 1st 2017 to December 31st 2017. A total of 848 patients who had indications for IVF were enrolled. The patients were classified by serum 25 (OH) D quartiles. The outcome parameters of IVF were compared in each group, including normal fertilization rate, high quality embryo rate, clinical pregnancy rate, implantation rate and live birth rate.

RESULTS

The median 25 (OH) D concentration was 15.25 ng/ml. Serum 25 (OH) D levels in women varied with the seasons. We found that serum 25 (OH) D levels were higher in autumn than other seasons, and the lowest level occurred in spring. Follicular fluid (FF) vitamin D levels were positively correlated with serum vitamin D levels (r = 0.85, P < 0.001). The levels of FF vitamin D were significantly higher than the levels of serum vitamin D (P < 0.001). Normal fertilization rates were significantly different among four groups (P = 0.007). The group of women with the highest serum 25 (OH) D levels had the highest normal fertilization rate. However, the clinical pregnancy rate, implantation rate and live birth rates were not significantly different among the four groups when the age, BMI, AMH, seasons of blood drawing, COH protocol, high quality embryo rate and number of embryos transferred were adjusted. In addition, we found that serum 25 (OH) D levels were significantly higher in patients received IVF than patients received R-ICSI (P = 0.013).

CONCLUSIONS

Among Chinese women, lower serum vitamin D levels are associated with a lower fertilization rate in IVF. However, vitamin D level was not associated with the clinical pregnancy and live birth rate following IVF.

Vitamin D and Anti-Müllerian Hormone Levels in Infertility Treatment: The Change-Point Problem

Background: Anti-Müllerian hormone (AMH) is considered to be one of the most significant indicators of women’s fertility. Many studies have shown that vitamin D may modify human reproductive functions; however, the results are conflicting. The composition of follicular fluid (FF) creates the biochemical environment of the oocyte and affects its quality, which later determines the embryo quality. In this study, we aimed to revise with advanced statistical techniques the relationship between AMH and vitamin D in FF. Methods: The study was designed as a prospective single-center study in infertile patients with AMH ≥ 0.7 ng/mL who underwent controlled ovarian hyperstimulation for in vitro fertilization. AMH and vitamin D levels in FF were measured. Next, the standard and advanced statistical (including segmented regression) techniques were applied. Results: We observed a negative linear correlation between levels of AMH in serum and FF and total vitamin D concentrations up to approximately 30 ng/mL; with a statistically significant relationship in FF. Beyond that concentration, the trend was positive but statistically insignificant. Conclusions: As an existing “change-point problem” was noticed, we suggest segmentation in the relationship between vitamin D and AMH during infertility treatment.