Leptin and soluble leptin receptor in follicular fluid

Neighborhood disadvantage is associated with decreased ovarian reserve in women with overweight and obesity

OBJECTIVE(S)

To evaluate the association between neighborhood disadvantage and ovarian reserve stratified by body mass index (BMI).

DESIGN

Cross-sectional cohort study.

SETTING

Single academic medical center.

PATIENT(S)

A total of 193 healthy reproductive-age women with regular menstrual cycles in the St. Louis, Missouri metropolitan area.

INTERVENTION(S)

Residence in a disadvantaged neighborhood.

MAIN OUTCOME MEASURE(S)

Ovarian reserve as assessed by ovarian antral follicle count (AFC) and serum anti-Müllerian hormone (AMH) concentration.

RESULT(S)

Women (n = 193) ranged from 20 to 44 years. The majority had overweight or obesity (59%, n = 117) with mean BMI of 28±7 kg/m2. Forty-eight women lived in the most disadvantaged neighborhood quartile, of which 75% had overweight or obesity, compared with 54% of the 145 women living in the 3 less disadvantaged neighborhood quartiles. When controlling for age, race, and smoking status, women with overweight or obesity living in the most disadvantaged neighborhoods had significantly lower AMH compared with those living in the less disadvantaged neighborhoods. Antral follicle count did not differ among women with overweight or obesity by neighborhood of residence. Neighborhood disadvantage was not associated with ovarian reserve by AFC or AMH in women with normal weight or underweight status.

CONCLUSION(S)

Living in a socioeconomically deprived area is associated with lower markers of ovarian reserve among women with an elevated BMI.

Fibroinflammatory Signatures Increase with Age in the Human Ovary and Follicular Fluid

The female reproductive system ages before any other organ system in the body. This phenomenon can have tangible clinical implications leading to infertility, miscarriages, birth defects and systemic deterioration due to estrogen loss. “Fibroinflammation” is a hallmark of aging tissues; there is an increase in inflammatory cytokines and fibrotic tissue in the aging ovarian stroma. We systematically evaluated immunomodulatory factors in human follicular fluid, which, like the stroma, is a critical ovarian microenvironment directly influencing the oocyte. Using a cytokine antibody array, we identified a unique fibroinflammatory cytokine signature in follicular fluid across an aging series of women (27.7–44.8 years). This signature (IL-3, IL-7, IL-15, TGFβ1, TGFβ3 and MIP-1) increased with chronologic age, was inversely correlated to anti-Müllerian hormone (AMH) levels, and was independent of body mass index (BMI). We focused on one specific protein, TGFβ3, for further validation. By investigating this cytokine in human cumulus cells and ovarian tissue, we found that the age-dependent increase in TGFβ3 expression was unique to the ovarian stroma but not other ovarian sub-compartments. This study broadens our understanding of inflammaging in the female reproductive system and provides a defined fibroinflammatory aging signature in follicular fluid and molecular targets in the ovary with potential clinical utility.

Revisiting the Impact of Local Leptin Signaling in Folliculogenesis and Oocyte Maturation in Obese Mothers

The complex nature of folliculogenesis regulation accounts for its susceptibility to maternal physiological fitness. In obese mothers, progressive expansion of adipose tissue culminates with severe hyperestrogenism and hyperleptinemia with detrimental effects for ovarian performance. Indeed, maternal obesity is associated with the establishment of ovarian leptin resistance. This review summarizes current knowledge on potential effects of impaired leptin signaling throughout folliculogenesis and oocyte developmental competence in mice and women.

Follicular fluid leptin as a marker for pregnancy outcomes in women undergoing IVF treatment: a systematic review and meta-analysis

Leptin is a hormone secreted mainly by the adipocytes with an essential role in the regulation of body weight. It acts on the reproductive axis at different sites, with stimulatory effects at the hypothalamus and pituitary and inhibitory interactions at the gonads. To investigate the influence of leptin on pregnancy outcomes in women undergoing IVF, we undertook a systematic review. A search of PubMed from 1966 to 2018 identified ten studies meeting the inclusion criteria. Outcomes were BMI, serum leptin level at hCG injection, serum and follicular fluid leptin level at the oocyte pick up, and serum 17β-oestradiol level at oocyte pick up time, oocytes retrieved and embryo transfer number. Results indicated that follicular fluid leptin concentrations at the oocyte pick up were significantly lower in women who became pregnant compared to those who did not (MD = -4.53 (ng/ml); 95% CI: -7.78, -1.78; p value < 0.006). In conclusion, elevated leptin concentrations in follicular fluid at oocyte pick up time is significantly associated with an adverse pregnancy outcome in women undergoing an IVF programme.

Leptin and its potential interest in assisted reproduction cycles

BACKGROUND

Leptin, an adipose hormone, has been shown to control energy homeostasis and food intake, and exert many actions on female reproductive function. Consequently, this adipokine is a pivotal factor in studies conducted on animal models and humans to decipher the mechanisms behind the infertility often observed in obese women.

METHODS

A systematic PubMed search was conducted on all articles, published up to January 2015 and related to leptin and its actions on energy balance and reproduction, using the following key words: leptin, reproduction, infertility, IVF and controlled ovarian stimulation. The available literature was reviewed in order to provide an overview of the current knowledge on the physiological roles of leptin, its involvement in female reproductive function and its potential interest as a prognostic marker in IVF cycles.

RESULTS

Animal and human studies show that leptin communicates nutritional status to the central nervous system and emerging evidence has demonstrated that leptin is involved in the control of reproductive functions by acting both directly on the ovaries and indirectly on the central nervous system. With respect to the clinical use of leptin as a biomarker in IVF cycles, a systematic review of the literature suggested its potential interest as a predictor of IVF outcome, as high serum and/or follicular fluid leptin concentrations have correlated negatively with cycle outcome. However, these preliminary results remain to be confirmed.

CONCLUSION

Leptin regulates energy balance and female reproductive function, mainly through its action on hypothalamic-pituitary-ovarian function, whose molecular and cellular aspects are progressively being deciphered. Preliminary studies evaluating leptin as a biomarker in human IVF seem promising but need further confirmation.

In Vitro Fertilization, Levels of Pro-Inflammatory Factors and Lipid Peroxidation

BACKGROUND

Infertility is a problem concerning 10-15% of the individuals in the fertile period. This study investigated effects of proinflammatory factors as well as lipid hydroperoxides (LPO) levels upon in vitro fertilization (IVF) success.

MATERIALS AND METHODS

In this prospective, non-randomized, controlled clinical study, sera obtained from 26 fertile (group-1), 26 infertile women before (group-2) and after (group-3) IVF treatment were analyzed. Leptin, leptin receptor, resistin, tumor necrosis factor-alpha (TNF-α), and C-reactive protein (CRP) were analyzed using enzyme-linked immunosorbent assay (ELISA). LPO was determined spectrophotometrically. Mann- Whitney U test, paired samples t test, Wilcoxon signed-rank test as well as Pearson correlation analysis by SPSS were performed for statistical analysis.

RESULTS

TNF-α, resistin and LPO levels increased (P=0.020, P=0.003, P=0.001, respectively) in group-3 compared to group-2. A significant increase in LPO was noted both in group-2 and -3 compared to controls (P=0.000). LPO were higher in non-pregnants than pregnants in group-2. For pregnants, significant correlations were observed between leptin and resistin in group-2 and TNF-α and leptin in group-3. None of these correlations were found for the women, who could not conceive.

CONCLUSION

LPO, leptin-resistin correlation, associations with TNF-α may be helpful during the interpretation of IVF success rates.

Assessment of follicular fluid leptin levels and insulin resistance as outcome predictors in women undergoing in vitro fertilization-intracytoplasmic sperm injection

OBJECTIVE

To analyze follicular fluid leptin (FFL) levels, abdominal obesity, and insulin resistance as predictors of in vitro fertilization (IVF)-intracytoplasmic sperm injection (ICSI) outcome.

DESIGN

Observational study.

SETTING

Academic medical center.

PATIENT(S)

A sample of 130 infertile women aged 26-40 years without polycystic ovary syndrome.

INTERVENTION(S)

Measurement of FFL levels in controlled ovarian hyperstimulation cycles with an antagonist and agonist protocol for IVF-ICSI.

MAIN OUTCOME MEASURE(S)

Live birth rate.

RESULT(S)

Mean FFL values were significantly higher in pregnancies not ending in a live birth, even after adjustment for waist circumference and insulin resistance. A multivariable model obtained with the use of logistic binary regression analysis showed that waist circumference and insulin resistance had no influence over IVF-ICSI outcomes, but a higher number of follicles, lower serum progesterone levels on the day before α-hCG administration, and lower FFL concentrations were significantly associated with a higher probability of having a live birth. The multivariate model reached a sensitivity of 87% and a specificity of 71% for predicting the possibility of pregnancy ending in a live birth.

CONCLUSION(S)

High FFL levels were associated with abdominal obesity, insulin resistance, and a lower live birth rate after IVF-ICSI. Further investigations are warranted to define the precise roles of leptin, obesity, and insulin resistance on IVF-ICSI outcomes.

Relationship between follicular fluid adipocytokines and the quality of the oocyte and corresponding embryo development from a single dominant follicle in in vitro fertilization/intracytoplasmic sperm injection cycles

OBJECTIVE

To investigate the association of individual follicular fluid (FF) leptin and adiponectin levels with the quality of the corresponding oocyte and embryo.

METHODS

We prospectively enrolled 67 women who underwent controlled ovarian hyperstimulation with 89 FF samples. FF and the corresponding oocyte was obtained from a single dominant preovulatory follicle at the time of oocyte retrieval. Concentrations of leptin and adiponectin were measured by enzyme-linked immunosorbent assay in an individual follicle. The oocyte quality, fertilization rate, and corresponding embryo development were assessed.

RESULTS

The FF level of leptin was significantly associated with body mass index (r=0.334, p<0.01). The FF adiponectin level was significantly higher in the normal fertilization group than the abnormal fertilization group (p=0.009) in the non-obese women. A lower FF leptin level was associated with a trend toward mature oocytes, normal fertilization, and good embryo quality, although these relationships were not statistically significant. The leptin:adiponectin ratio of FF did not differ significantly according to oocyte and embryo quality. The quality of the oocyte and embryo was not associated with the FF leptin level tertile. However, the normal fertilization rate was positively associated with FF adiponectin level tertile. There was a trend towards improved oocytes and normal fertilization rates with the lowest tertile of the FF leptin:adiponectin ratio, but this difference was not statistically significant.

CONCLUSION

Our results suggest that a high FF adiponectin concentration could be a predictor of normal fertilization. However, the FF leptin concentration and leptin:adiponectin ratio is not significantly related to oocyte maturity and corresponding embryo development.

Short-term energy deprivation alters activin a and follistatin but not inhibin B levels of lean healthy women in a leptin-independent manner

CONTEXT

Leptin is a potent modulator of the hypothalamic-pituitary-gonadal axis mediating the effect of energy deprivation on several hypothalamic-pituitary-peripheral axes. Activin A, inhibin B, and follistatin (FST) also regulate the hypothalamic-pituitary-gonadal axis in humans. It remains unknown whether energy deprivation affects these hormone levels in a leptin-dependent or -independent manner.

OBJECTIVE

We investigated 1) day-night variability patterns of activin, inhibin, and FST in the fed state, 2) whether their levels are affected by fasting, and 3) whether such an effect is mediated by leptin in physiological replacement or pharmacological doses.

DESIGN

We conducted two studies in healthy, eumenorrheic females, each comprising three separate admissions. In study 1, six women were maintained for 72 h 1) on isocaloric diet, 2) fasting while receiving placebo, or 3) fasting while receiving metreleptin in physiological replacement doses. In study 2, five women were administered physiological or pharmacological metreleptin doses (0.01, 0.1, or 0.3 mg/kg i.v. four times daily).

RESULTS

Neither activin A nor FST had a pulsatile or day-night variability pattern. Inhibin B levels were also nonpulsatile, but a trend toward a day-night pattern was noted. When compared with the fed state, inhibin B levels remained unchanged, whereas FST levels increased (P = 0.01) and activin A decreased (P = 0.01) in the fasting state. These changes were not corrected with metreleptin administered in replacement or pharmacological doses.

CONCLUSIONS

Short-term energy deprivation alters levels of activin A and FST, but these effects are not mediated by leptin.

Extra- and intra-ovarian factors in polycystic ovary syndrome: impact on oocyte maturation and embryo developmental competence

BACKGROUND

Polycystic ovary syndrome (PCOS) is a common metabolic dysfunction and heterogeneous endocrine disorder in women of reproductive age. Although patients with PCOS are typically characterized by increased numbers of oocytes retrieved during IVF, they are often of poor quality, leading to lower fertilization, cleavage and implantation rates, and a higher miscarriage rate.

METHODS

For this review, we searched the database MEDLINE (1950 to January 2010) and Google for all full texts and/or abstract articles published in English with content related to oocyte maturation and embryo developmental competence.

RESULTS

The search showed that alteration of many factors may directly or indirectly impair the competence of maturating oocytes through endocrine and local paracrine/autocrine actions, resulting in a lower pregnancy rate in patients with PCOS. The extra-ovarian factors identified included gonadotrophins, hyperandrogenemia and hyperinsulinemia, although intra-ovarian factors included members of the epidermal, fibroblast, insulin-like and neurotrophin families of growth factors, as well as the cytokines.

CONCLUSIONS

Any abnormality in the extra- and/or intra-ovarian factors may negatively affect the granulosa cell-oocyte interaction, oocyte maturation and potential embryonic developmental competence, contributing to unsuccessful outcomes for patients with PCOS who are undergoing assisted reproduction.

Leptin gene and protein expression in the ovary during the oestrous cycle and early pregnancy in pigs

Leptin, the product of the obese gene, is the hormone originally identified in adipocytes. It is involved in the control of satiety and energy metabolism. More recent observations suggest that leptin plays an important role in reproduction. Leptin mRNA and protein have been found in the human and the murine ovary. However, the expression of leptin in the porcine ovary has not been examined. Therefore, the aim of the present work was to compare the expression levels of porcine leptin mRNA by semiquantitative RT-PCR and in situ hybridization, as well as leptin protein by Western blotting in the corpus luteum (CL) and ovarian stroma (OS) during mid- and late-luteal phase of the oestrous cycle as well as during days 14-16 and 30-32 of pregnancy. Leptin gene and protein expression in CL was increased on days 14-16 of the cycle compared with pregnant animals. Leptin gene expression in OS was higher during the late-luteal phase of the cycle than on days 30-32 after conception. However, comparison of leptin protein expression in OS between days 14-16 of the cycle and days 30-32 of pregnancy indicates a higher protein expression during pregnancy. Moreover, leptin gene expression was higher in porcine CL and OS on days 14-16 of pregnancy in comparison to days 30-32. Contrary to leptin mRNA expression, a higher leptin protein expression was observed on days 30-32 compared with days 14-16 after conception. In summary, the present study provides the first evidence that leptin mRNA and protein occur in porcine ovary and vary during the oestrous cycle and pregnancy. Moreover, the obtained results indicate that also locally synthesized leptin may participate in the control of pig reproduction by exercising its action at the ovarian level.

Leptin and ObRa/MEK signalling in mouse oocyte maturation and preimplantation embryo development

Recent studies indicate that LH stimulates production of ovarian paracrine factors that induce meiosis of the oocyte. DNA microarray analyses of ovarian transcripts were performed in mice and major increases of a short isoform of leptin receptor, ObRa, were identified by the preovulatory LH/human chorionic gonadotrophin (HCG) surge. In oocytes, the level of ObRa transcripts was increased shortly after HCG stimulation, whereas the level of ObRb transcripts was not changed. Leptin was produced by cumulus, granulosa, theca and interstitial cells of ovaries and its transcript level was not regulated during gonadotrophin treatment. Treatment with leptin promoted germinal vesicle breakdown (GVBD) in oocytes within preovulatory follicles, and enhance first polar body extrusion in both cumulus-oocyte complexes and denuded oocytes. The leptin-promoted GVBD and first polar body extrusion were blocked by a mitogen-activated protein kinase extracellular signal regulated kinase kinases (MEK)1/2 inhibitor, U0126, but not its inactive analogue U0124. Furthermore, leptin promoted fertilization of oocytes and the in-vitro development of zygotes to preimplantation embryos. These findings suggest paracrine roles of leptin in the enhancement of nuclear maturation of oocytes through MEK1/2 signalling, and in the promotion of cytoplasmic maturation essential for successful oocyte development to the preimplantation embryos.

Leptin deficiency: clinical implications and opportunities for therapeutic interventions

The discovery of leptin has significantly advanced our understanding of the metabolic importance of adipose tissue and has revealed that both leptin deficiency and leptin excess are associated with severe metabolic, endocrine, and immunological consequences. We and others have shown that a prominent role of leptin in humans is to mediate the neuroendocrine adaptation to energy deprivation. Humans with genetic mutations in the leptin and leptin receptor genes have deregulated food intake and energy expenditure leading to a morbidly obese phenotype and a disrupted regulation in neuroendocrine and immune function and in glucose and fat metabolism. Observational and interventional studies in humans with (complete) congenital leptin deficiency caused by mutations in the leptin gene or with relative leptin deficiency as seen in states of negative energy balance such as lipoatrophy, anorexia nervosa, or exercise-induced hypothalamic and neuroendocrine dysfunction have contributed to the elucidation of the pathophysiological role of leptin in these conditions and of the clinical significance of leptin administration in these subjects. More specifically, interventional studies have demonstrated that several neuroendocrine, metabolic, or immune disturbances in these states could be restored by leptin administration. Leptin replacement therapy is currently available through a compassionate use program for congenital complete leptin deficiency and under an expanded access program to subjects with leptin deficiency associated with congenital or acquired lipoatrophy. In addition, leptin remains a potentially forthcoming treatment for several other states of energy deprivation including anorexia nervosa or milder forms of hypothalamic amenorrhea pending appropriate clinical trials.

Leptin in humans: lessons from translational research

Leptin has emerged over the past decade as a key hormone in not only the regulation of food intake and energy expenditure but also in the regulation of neuroendocrine and immune function as well as the modulation of glucose and fat metabolism as shown by numerous observational and interventional studies in humans with (complete) congenital or relative leptin deficiency. These results have led to proof-of-concept studies that have investigated the effect of leptin administration in subjects with complete (congenital) leptin deficiency caused by mutations in the leptin gene as well as in humans with relative leptin deficiency, including states of lipoatrophy or negative energy balance and neuroendocrine dysfunction, as for instance seen with hypothalamic amenorrhea in states of exercise-induced weight loss. In those conditions, most neuroendocrine, metabolic, or immune disturbances can be restored by leptin administration. Leptin replacement therapy is thus a promising approach in several disease states, including congenital complete leptin deficiency, states of energy deprivation, including anorexia nervosa or milder forms of hypothalamic amenorrhea, as well as syndromes of insulin resistance seen in conditions such as congenital or acquired lipodystrophy. In contrast, states of energy excess such as garden-variety obesity are associated with hyperleptinemia that reflects either leptin tolerance or leptin resistance. For those conditions, development of leptin sensitizers is currently a focus of pharmaceutical research. This article summarizes our current understanding of leptin's role in human physiology and its potential role as a novel therapeutic option in human disease states associated with a new hormone deficiency, ie, leptin deficiency.

Evaluation of oocyte quality: morphological, cellular and molecular predictors

Mounting evidence that oocyte quality profoundly affects fertilisation an d subsequent embryo development drives the continued search for reliable predictors of oocyte developmental competence. In the present review, we provide an overall summary and analysis of potential criteria that can be used to evaluate oocyte quality. These criteria are specifically classified as morphological and cellular/molecular predictors. Traditional methods for the evaluation of oocyte quality are based on morphological classification of thefollicle, cumulus-oocytecomplex, polar body and/or meiotic spindle. Although the use of morphological characteristics as predictors of oocyte quality is controversial, such a grading system can provide valuable information for the preselection of oocytes with higher developmental competence and, therefore, may maximise embryo developmental outcome. Several intrinsic markers (such as mitochondrial status and glucose-6-phosphate dehydrogenase 1 activity) and extrinsic markers (such as apoptosis of follicular cells and levels of the transforming growth factor-beta superfamily in follicular fluid or serum) have also been reported as useful indicators of oocyte competence and embryo quality. Compared with the morphological parameters, these cellular and molecular predictors of oocyte quality may prove to be more precise and objective, although further studies and refinement of techniques are needed.

The utility of serum leptin and follicular fluid leptin, estradiol, and progesterone levels during an in vitro fertilization cycle

PURPOSE

To prospectively evaluate serum and follicular fluid leptin, estradiol, and progesterone levels during in vitro fertilization.

METHODS

Prospective observational study measuring serum levels at six points during the IVF cycle and follicular fluid at the time of retrieval.

RESULTS

Serum leptin and estradiol levels both significantly increased for the individual patients during the IVF stimulation process. None of the leptin levels differed based on pregnancy outcome. BMI significantly correlated with all leptin levels. Follicular fluid estradiol correlated with serum estradiol only in pregnant patients (r = 0.97, p<0.01) and was unrelated in non-pregnant patients (r=-0.15, p=0.81).

CONCLUSION

Serum and follicular leptin levels are highly correlated. Leptin levels increase during the IVF cycle and vary between patients based on maternal BMI, but do not correlate with other serum hormone levels or pregnancy outcome. Pregnancy outcome success was reflected in the relationship between follicular fluid and serum levels of estradiol, independent of leptin levels.

Intra-follicular leptin concentration as a predictive factor for in vitro oocyte fertilization in assisted reproductive techniques

BACKGROUND

Granulosa-cells are able to produce and store leptin, suggesting that this hormone is locally involved in the regulation of follicular growth. In this study, the role of follicular fluid (FF) leptin concentration in predicting oocyte fertilization and embryo quality was evaluated in 35 normogonadotrophic women undergoing controlled ovarian stimulation (COS) for assisted reproductive techniques.

MATERIALS AND METHODS

Leptin concentration was measured in 47 consecutively collected FF in which a mature oocyte had been found during the ovum pick-up. Embryos deriving from fertilized oocytes were submitted to quality scoring systems.

RESULTS

Mean leptin concentration was significantly higher in FF whose oocytes showed 2 pronuclei (no. 25) when compared with those with no evidence of fertilization (no. 22) at the 16-18 h check (26.0+/-6.1 vs 15.3+/-10.6 ng/ml, respectively, p<0.01). Follicular mean diameters were similar in the two groups (21.4+/-3.4 and 21.0+/-5.1 mm, respectively). Logistic regression analysis identified FF leptin levels as the best predictive parameter for oocyte fertilization (p<0.001). When receiving operating characteristics curve was employed, a FF leptin concentration of 20.25 ng/ml was the most reliable cut-off in predicting fertilization of oocytes. FF with leptin concentrations higher than this value (no. 27) had an oocyte fertilization rate of 85.7%. In contrast, FF levels < or =20.25 ng/ml (no. 20) were associated with a rate of 16.7% (p<0.05). No correlation emerged between FF leptin and the score attributed to 15 valuable embryos at the zygote stage (r=-0.01) and at 48 h after insemination (r=0.1).

CONCLUSIONS

FF leptin levels are a better predictor of oocyte fertilization success rates than follicular diameter. These results underline the relevance of FF variables in developing methods for oocyte selection.

Serum and follicular fluid leptin levels are correlated with human embryo quality

This prospective study was undertaken to reassess the prognostic value of leptin during critical stages of in vitro fertilization-embryo transfer (IVF-ET) and address its role in the functional staging of assisted reproductive technologies at the level of embryo quality. Serum and follicular fluid samples of 100 selected women undergoing the long IVF-ET protocol were collected for leptin and embryo quality determination. The highest serum leptin concentration (52.11 ± 4.27 ng/ml) was observed on ovum pick up day, while follicular fluid leptin was higher than all serum samples examined (62.59 ± 5.73 ng/ml). Serum leptin above 59.48 ± 7.6 ng/ml was associated with ‘poor’ embryo quality and above 56.87 ± 5.52 ng/ml with pregnancy failure. Elevated leptin concentrations were associated with reduced ovarian stimulation and response, follicle maturation, embryo quality and pregnancy success. Our findings suggest that leptin modulates embryo quality and may serve as a sensitive marker of IVF outcome.

Concentrations of leptin and C-reactive protein in serum and follicular fluid during assisted reproductive cycles

BACKGROUND

There are only a few studies that have investigated inflammatory processes during ovarian hyperstimulation, with contradictory results especially concerning outcome. The aim of the study was to investigate the inflammatory markers C-reactive protein and leptin in serum and follicular fluid and to correlate these with the outcome.

METHODS

One hundred and sixty-two gonadotrophin stimulated cycles were evaluated. Serum concentrations of leptin and C-reactive protein were measured at the initiation of stimulation, on the day of hCG administration or the day before, and on the day of oocyte retrieval. They were also determined in the follicular fluid.

RESULTS

Serum leptin and C-reactive protein levels increased significantly during stimulation until the day of oocyte pick up, but following different patterns. After stimulation, they correlated with each other in serum and follicular fluid, but not with estradiol or progesterone concentration, embryo quality, or the pregnancy rate.

CONCLUSIONS

Leptin and C-reactive protein levels change significantly during assisted reproductive treatment. In contrast to estradiol they are, however, not a marker of success.