Christina I. Messini

Prognostic value of follicular fluid 25-OH vitamin D and glucose levels in the IVF outcome

ObjectivesThe aim of the present study was to measure serum and follicular fluid 25-OH vitamin D and glucose levels in women who underwent IVF-ET treatment and to further investigate whether the circulating 25-OH vitamin D and glucose levels correlate with IVF success.MethodsThis prospective observational study included 101 consecutive women who underwent 101 IVF-ICSI ovarian stimulation cycles and were allocated to one of the three groups according to their follicular fluid 25-OH vitamin D concentrations. Group A (n = 31) with less than 20 ng/ml, group B (n = 49) with vitamin levels between 20.1 and 30 ng/ml and group C (n = 21) with more than 30 ng/ml vitamin concentration.ResultsFollicular fluid vitamin levels significantly correlated with the quality of embryos in total (r = -0.27, p = 0.027), while the quality of embryos of group C were of lower quality as compared to those of groups A and B (p = 0.009). Follicular fluid glucose levels were lower in women of group C as compared to the respective levels of groups A and B (p = 0.003). Clinical pregnancy rate demonstrated in 14.5% in women of group C and 32.3% and 32.7% in groups A and B, respectively (p = 0.047).ConclusionThe data suggests that excess serum and follicular fluid vitamin levels in combination with decreased follicular fluid glucose levels have a detrimental impact on the IVF outcome.

Intraperitoneal dissemination of endometrial cancer cells after hysteroscopy: a systematic review and meta-analysis

Introduction: Hysteroscopy is a diagnostic procedure with a high accuracy in diagnosing endometrial cancer. Because of the increase of intrauterine pressure during distention media inflation, several retrospective studies postulated that it may result in cancer cell dissemination within the peritoneal cavity through the fallopian tubes. We therefore set to estimate whether hysteroscopy increases the risk for intraperitoneal cancer cell dissemination in patients with endometrial cancer and the risk of disease upstaging in patients with clinically early-stage disease. Methods: We searched the PubMed, the ISI Web of Science, and the Cochrane Library through July 2009. Eligible trials were all controlled clinical trials in which patients were allocated to hysteroscopy (alone or after other diagnostic procedure, eg, dilation and curettage and biopsy) versus any other diagnostic procedure except hysteroscopy or no procedure before surgery for endometrial carcinoma. Results: Nine trials were included in our analysis. One thousand fifteen patients with histologically proven endometrial carcinoma were allocated to hysteroscopy or no hysteroscopy before surgery. Hysteroscopy resulted in a significantly higher rate of malignant peritoneal cytology (odds ratio [OR], 1.78; 95% confidence interval [CI], 1.13-2.79; P = 0.013) and significantly higher disease upstaging owing solely to the presence of malignant cells in the peritoneal cavity (OR, 2.61; 95% CI, 1.47-4.63; P = 0.001) compared with no hysteroscopy. When isotonic sodium chloride was used as distention medium, hysteroscopy resulted in a statistically significant higher rate of malignant peritoneal cytology (OR, 2.89; 95% CI, 1.48-5.64; P = 0.002), whereas a nonsignificant trend for higher malignant cells was observed in patients allocated to the hysteroscopy group (OR, 3.23; 95% CI, 0.94-11.09; P = 0.062) when inflated media pressure reached or exceeded 100 mm Hg. Conclusions: Hysteroscopy in patients with endometrial cancer hints a risk for cancer cell dissemination within the peritoneal cavity. Prospective and sufficiently powered trials are needed to clarify whether the risk of cancer cell spreading is correlated with worse prognosis.

Effect of ghrelin on gonadotrophin secretion in women during the menstrual cycle

BACKGROUND It has been suggested that ghrelin may affect reproduction in animals by decreasing pituitary LH secretion. The role of ghrelin on LH secretion in women has not been investigated. Our aim was to assess the effect of ghrelin administration on basal and GnRH-induced LH secretion during the menstrual cycle. METHODS Normally cycling women (n = 10) received on Day 3 of three consecutive cycles a single bolus i.v. of either ghrelin (1 microg/kg, cycle 1) or GnRH (100 microg, cycle 2) or GnRH plus ghrelin (cycle 3). In cycle 1, ghrelin was also injected in late follicular and mid-luteal phase of the cycle. Saline was injected in a preceding cycle (cycle 1, control). Blood samples were taken before drugs or saline injection (time 0) as well as at -15, 15, 30, 45, 60, 75, 90 and 120 min. RESULTS Plasma ghrelin levels increased rapidly, peaking at 15 or 30 min (P < 0.001), then decreased steadily, approaching pre-injection levels at 120 min. Serum FSH, LH, estradiol and progesterone levels remained unchanged. The stimulating effect of GnRH on LH and FSH secretion was unaffected by ghrelin injection. In contrast to saline, ghrelin stimulated a significant increase in growth hormone levels. CONCLUSIONS Under these experimental conditions, our results demonstrate for the first time the inability of a bolus of ghrelin to affect basal and GnRH-induced LH and FSH secretion. It is suggested that ghrelin does not play a major physiological role in gonadotrophin secretion in women.

Elimination Half-Life of Anti-Müllerian Hormone

CONTEXT Anti-Müllerian hormone (AMH) is a glycoprotein that is secreted by the granulosa cells in the human ovary. In the postpubertal female, circulating AMH reflects the number of follicles within the ovary. It is mandatory to know the serum elimination half-life (t(1/2)) of AMH to study in vivo short-term changes of the hormone. OBJECTIVE Our objective was to determine the kinetics of decay of AMH in the human female. PATIENTS, DESIGN, AND SETTING Premenopausal women undergoing total abdominal hysterectomy plus bilateral salpingo-oophorectomy participated in this cohort study (n = 21) at an academic tertiary referral center. INTERVENTIONS Serum samples were obtained immediately before surgery and in 12-h intervals thereafter for 8 d. MAIN OUTCOME MEASURE AMH elimination was calculated, applying a one-compartment model with first-order kinetics. RESULTS Mean preoperative AMH levels were 0.67 ng/ml (range, 0.1-1.78 ng/ml) and dropped to 0.08 ng/ml within 84 h after surgery. The AMH decay followed first-order kinetics. The mean terminal t(1/2) of AMH was calculated as 27.6 ± 0.8 h. CONCLUSION AMH elimination reaches approximately 84% after 3 d, approximately 91% after 4 d, approximately 95% after 5 d, and can be considered complete after 8 d.

Vaginal progesterone gel for luteal phase support in IVF/ICSI cycles: a meta-analysis

OBJECTIVE To investigate whether vaginal progesterone gel may result in similar or higher pregnancy rates compared with all other vaginal progesterone forms when used for luteal-phase support. DESIGN Meta-analysis of randomized controlled trials using odds ratios (OR) and 95% confidence intervals (CI). PATIENT(S) Infertile women undergoing IVF or ICSI. INTERVENTION(S) Vaginal progesterone gel 90 mg once or twice daily versus any other vaginal progesterone form for luteal phase support. MAIN OUTCOME MEASURE(S) Clinical pregnancy rates. RESULT(S) Seven randomized controlled trials, involving 2,447 patients, were included in the analysis. No difference was observed in the overall clinical pregnancy rate when comparing vaginal progesterone gel with any other vaginal progesterone form. Moreover, clinical pregnancy rates were similar in protocols using only GnRH agonists and when comparing vaginal gel with the traditional treatment of 200 mg×3 vaginal progesterone capsules. CONCLUSION(S) This meta-analysis provides solid evidence that no significant difference exists between vaginal gel and all other vaginal progesterone forms in terms of clinical pregnancy rates.

Molecular and Cellular Mechanisms of Sperm-Oocyte Interactions Opinions Relative to in Vitro Fertilization (IVF)

One of the biggest prerequisites for pregnancy is the fertilization step, where a human haploid spermatozoon interacts and penetrates one haploid oocyte in order to produce the diploid zygote. Although fertilization is defined by the presence of two pronuclei and the extraction of the second polar body the process itself requires preparation of both gametes for fertilization to take place at a specific time. These preparations include a number of consecutive biochemical and molecular events with the help of specific molecules and with the consequential interaction between the two gametes. These events take place at three different levels and in a precise order, where the moving spermatozoon penetrates (a) the outer vestments of the oocyte, known as the cumulus cell layer; (b) the zona pellucida (ZP); where exocytosis of the acrosome contents take place and (c) direct interaction of the spermatozoon with the plasma membrane of the oocyte, which involves a firm adhesion of the head of the spermatozoon with the oocyte plasma membrane that culminates with the fusion of both sperm and oocyte membranes (Part I). After the above interactions, a cascade of molecular signal transductions is initiated which results in oocyte activation. Soon after the entry of the first spermatozoon into the oocyte and oocyte activation, the oocyte’s coat (the ZP) and the oocyte’s plasma membrane seem to change quickly in order to initiate a fast block to a second spermatozoon (Part II). Sometimes, two spermatozoa fuse with one oocyte, an incidence of 1%–2%, resulting in polyploid fetuses that account for up to 10%–20% of spontaneously aborted human conceptuses. The present review aims to focus on the first part of the human sperm and oocyte interactions, emphasizing the latest molecular and cellular mechanisms controlling this process.

The role of gonadotropins in the follicular phase.

Folliculogenesis in humans is a lengthy process that involves several regulators. Pituitary gonadotropins play crucial roles in the late stages, particularly in the last 15 days of follicle maturation. During the intercycle rise of follicle‐stimulating hormone (FSH), selection of the dominant follicle takes place. This is a complex process that also involves locally produced substances. At the same time, luteinizing hormone (LH) stimulates the synthesis of androgens, which serve as the substrate for the production of estrogens. During the second half of the follicular phase, the follicle becomes dependent on LH. Induction of multiple follicular development by exogenous FSH results in a marked suppression of endogenous LH. For normal follicle maturation, both an LH threshold and an LH ceiling have been considered. In the context of an in vitro fertilization program, application of protocols for ovarian stimulation that will prevent the marked suppression of endogenous LH secretion might provide a better approach to treatment optimization.

Novel aspects of the endocrinology of the menstrual cycle

Ovarian control of gonadotrophin secretion is normally achieved via the feedback mechanisms mediated by oestradiol and progesterone. Evidence has been provided that nonsteroidal substances, such as inhibin A and B, participate in the negative feedback control of FSH secretion. Another nonsteroidal ovarian substance is gonadotrophin surge-attenuating factor (GnSAF), the activity of which is particularly evident in women undergoing ovulation induction. Accumulating evidence has suggested that GnSAF plays a physiological role during the menstrual cycle. In particular, this factor antagonizes the sensitizing effect of oestradiol on the pituitary response to gonadotrophin-releasing hormone during the follicular phase of the cycle. A hypothesis has been developed that, in the late follicular phase, the activity of GnSAF is reduced and this facilitates the sensitizing effect of oestradiol on the pituitary, thus enforcing the massive discharge of gonadotrophins at the midcycle LH surge. The interaction of oestradiol, progesterone and GnSAF on the hypothalamic-pituitary system provides a novel approach to explain the mechanisms which control LH secretion during the normal menstrual cycle. The ovarian control of gonadotrophin secretion during the normal menstrual cycle is achieved via negative and positive feedback mechanisms. The steroids oestradiol and progesterone are the main regulators; however, nonsteroidal substances, such as inhibin A and inhibn B, also participate. Accumulating evidence has demonstrated that another nonsteroidal ovarian substance, gonadotrophin surge-attenuating factor (GnSAF), plays a key role in the control of LH secretion during the follicular phase and at midcycle, providing thus a novel aspect in the ovarian control of gonadotrophin secretion during the human menstrual cycle. The ovarian control of gonadotrophin secretion during the normal menstrual cycle is achieved via negative and positive feedback mechanisms. The steroids oestradiol and progesterone are the main regulators; however, nonsteroidal substances, such as inhibin A and inhibn B, also participate. Accumulating evidence has demonstrated that another nonsteroidal ovarian substance, gonadotrophin surge-attenuating factor (GnSAF), plays a key role in the control of LH secretion during the follicular phase and at midcycle, providing thus a novel aspect in the ovarian control of gonadotrophin secretion during the human menstrual cycle.

Effect of the Position of the Polar Body During ICSI on Fertilization Rate and Embryo Development

This prospective study was designed to evaluate and clarify further whether the position of the polar body (PB) in relation to injection site during intracytoplasmatic sperm injection (ICSI) has an impact on fertilization and developmental rates and consequently clinical pregnancy outcome. The study included 264 patients undergoing 306 ICSI cycles from September 2007 to January 2009 performed by the same practitioner. Of all oocytes retrieved, 1736 were in metaphase II (MII). From every woman reaching ovum pick up, all MII-collected oocytes were allocated to 1 of the 4 groups according to PB orientation. In group A, MII oocytes were injected with the PB at 6 o’clock, group B with the PB at 7 o’clock, group C with the PB at 11 o’clock, and a group D with the PB at 12 o’clock. A significantly higher proportion of fertilized oocytes were produced from oocytes that had been injected with the PB at 11 o’clock (79.2%) as compared to those at 6 o’clock (70.5%), 7 o’clock (64.4%), and 12 o’clock (68.8%). Furthermore, embryos derived from oocytes that were injected with the PB at 11 o’clock appeared to be of higher quality score than those of the other groups of oocytes. A higher clinical pregnancy rate (28.7%) was obtained after the transfer of embryos from oocytes that had been injected with the PB at 11 o’clock. Given the higher fertilization, developmental, and pregnancy rate in the 11 o’clock group, it is suggested that this may be the preferred position of the PB at ICSI.

Effect of ghrelin and thyrotropin-releasing hormone on prolactin secretion in normal women.

It is known that ghrelin stimulates the secretion of prolactin in women. The aim of this study was to examine the effect of exogenous thyrotropin-releasing hormone (TRH) on ghrelin-induced prolactin release. Ten healthy normally cycling women were studied in four menstrual cycles. The women were injected intravenously in late follicular phase (follicle size 16-17 mm) with a single dose of normal saline (cycle 1), ghrelin (1 microg/kg) (cycle 2), thyrotropin-releasing hormone (200 microg) (cycle 3), and ghrelin plus thyrotropin-releasing hormone (cycle 4). Blood samples in relation to saline or drugs injection (time 0) were taken at -15, 0, 15, 30, 45, 60, 75, 90, and 120 min. The prolactin and growth hormone responses were assessed. After ghrelin administration (cycles 2 and 4), plasma ghrelin, serum prolactin, and growth hormone levels increased rapidly, peaking at 15-30 min (p<0.001). The injection of thyrotropin-releasing hormone (cycle 3) stimulated prolactin secretion markedly (p<0.001), but reduced growth hormone levels significantly (p<0.05). Ghrelin induced a smaller prolactin increase than thyrotropin-releasing hormone (p<0.05). The combination of ghrelin and thyrotropin-releasing hormone induced a similar increase in prolactin levels as with thyrotropin-releasing hormone alone. No changes in growth hormone and prolactin levels were seen after saline injection. These results demonstrate that the stimulating effect of ghrelin on prolactin secretion is not additive with that of thyrotropin-releasing hormone.