Optimal stimulation protocols for in vitro fertilization

Ovarian response determines the luteinizing hormone suppression threshold for patients following the gonadotrophin releasing hormone antagonist protocol: A retrospective cohort study

Background

Ovarian reactivity to gonadotrophin stimulation varies, and individual adjustments to the timing and dose of gonadotrophin-releasing hormone (GnRH) antagonist administration are necessary to prevent excessive increases and decreases in luteinizing hormone (LH) levels in patients with different ovarian response following the GnRH antagonist (GnRH-A) protocol. The present study aims to investigate optimal LH suppression thresholds for patients with normal ovarian response (NOR), high ovarian response (HOR), and poor ovarian response (POR) following the GnRH-A protocol respectively.

Methods

A total of 865 in vitro fertilization (IVF) cycles using a flexible or fixed GnRH-A protocol were included. Patients were categorized into the HOR, NOR, or POR group according to their anti-Müllerian hormone (AMH) levels. Then, patients in each group were stratified into one of four subgroups according to the quartile (Q1-Q4) of the basal LH level to LH on triggering day ratio (bLH/hLH). The primary outcomes were the clinical pregnancy and live birth rates, and the secondary outcomes were the number of oocytes retrieved, MII oocytes, two pronucleus (2PN) embryos, and good-quality embryos.

Results

There were 526 patients with NOR, 180 with HOR, and 159 with POR. Basal LH level, LH on triggering day and bLH/hLH were identified as independent predictors of clinical pregnancy rate and live birth rate by logistics regression analysis. Compared to those with NOR, patients with POR had the lowest embryo implantation rate (22.6% vs. 32.8%, P < 0.05), clinical pregnancy rate (32.3% vs. 47.3%, P < 0.05) and live birth rate (22.6 vs. 37.8%, P < 0.05) of fresh embryo transfer (ET). The embryo implantation, clinical pregnancy and live birth rates of frozen embryo transfer (FET) were not significantly different among the three groups. In the subgroup analysis, patients with HOR had the highest embryo implantation rate (51.6%, P < 0.05), clinical pregnancy rate (68.4%, P < 0.05) and live birth rate (52.6%, P < 0.05) of ET in Q3, with a bLH/hLH ratio of 2.40-3.69. In the NOR group, the embryo implantation rate (41.9%, P < 0.05), clinical pregnancy rate (61.5%, P < 0.05) and live birth rate (50.8%, P < 0.05) of ET and live birth rate (53.1%, P < 0.05) of FET were highest in Q2, with a bLH/hLH ratio of 1.29-2.05. Patients with POR had the highest clinical pregnancy rate (57.1%, P < 0.05) and live birth rate (42.9%, P < 0.05) of ET in Q2, with a bLH/hLH ratio of 0.86-1.35.

Conclusions

In the present study, the bLH/hLH ratio represented the LH suppression threshold. The subgroup analysis of HOR, NOR and POR showed that, the LH suppression threshold varies according to ovarian response. We recommend LH suppression thresholds of 2.40-3.69 for HOR, 1.29-2.05 for NOR, and 0.86-1.35 for POR to obtain the highest clinical pregnancy rate and live birth rate. This study provides comprehensive and precise references for clinicians to monitor LH levels individually during controlled ovarian stimulation (COS) according to the patient's ovarian response following the GnRH-A protocol.

Ultra-low-dose and very-low-dose Lupron downregulation protocols for poor responders based on POSEIDON group 3 and 4 classifications

PURPOSE

The objective of this study was to assess if very-low-dose Lupron (VLDL) and ultra-low-dose Lupron (ULDL) protocols can have comparable cycle outcomes when compared to other "poor responder" stimulation protocols based on POSEIDON classification groups 3 (PG3) and 4 (PG4).

METHODS

A retrospective cohort study at a single, large academic center was performed. Women in PG3 (age < 35, AMH < 1.2 ng/mL) or PG4 (age ≥ 35, AMH < 1.2 ng/mL) undergoing in vitro fertilization using an ULDL (Lupron 0.1 to 0.05 mg daily), VLDL (Lupron 0.2 to 0.1 mg daily), microflare (Lupron 0.05 mg twice a day), estradiol priming/antagonist, antagonist, or minimal stimulation protocols from 2012 to 2021 were included. The primary outcome was the number of mature oocytes (MII) obtained. The secondary outcome was live birth rate (LBR).

RESULTS

The cohort included 3601 cycles. The mean age was 38.1 ± 3.8 years. In the PG3 group, ULDL and VLDL protocols produced a comparable number of MIIs (5.8 ± 4.3 and 5.9 ± 5.4, respectively) and live births (33.3% and 33.3%, respectively) when compared to other protocols. In the PG4 group, ULDL and VLDL protocols resulted in a higher percentage of MIIs when compared to microflare or minimal stimulation (Microflare/ULDL: adjusted relative risk (aRR) 0.78 (95% CI 0.65, 0.95); min stim/ULDL: aRR 0.47 (95% CI 0.38, 0.58); microflare/VLDL: aRR 0.77 (95% CI 0.63, 0.95); min stim/VLDL: aRR 0.47 (95% CI 0.38, 0.95)). There were no significant differences in LBR.

CONCLUSION

Dilute Lupron downregulation protocols have comparable outcomes to other poor responder protocols and are reasonable to use.

LH level on ovulation trigger day has a different impact on the outcomes of agonist and antagonist regimens during in vitro fertilization

BACKGROUND

To assess the impact of the luteinizing hormone level on ovulation trigger day (LHOTD) on in vitro fertilization (IVF) outcomes in gonadotropin-releasing hormone (GnRH) agonist and antagonist regimens during fresh embryo transfer cycles.

METHODS

A stepwise, progressive multivariate regression model was introduced to assess the effect of the LHOTD on clinical pregnancy and live birth rates. Mantel‒Haenszel stratification analysis was used to examine the association between the LHOTD and clinical outcomes with the antagonist regimen.

RESULTS

The LHOTD had different distributions in the agonist and antagonist regimens. The cycles were assigned into three LHOTD tertile groups. In the agonist regimen, compared with the 1^st tertile (T1), in the 2^nd (T2) and 3^rd (T3) tertiles, the adjusted odds ratios (ORs) (95% confidence intervals [CIs], P value) were 1.187 (1.047-1.345, 0.007) and 1.420 (1.252-1.610, < 0.001) for clinical pregnancy, respectively, and 1.149 (1.009-1.309, 0.036) and 1.476 (1.296-1.681, < 0.001) for live birth. In the antagonist regimen, there was no significant difference in clinical pregnancy and live birth rates among the tertiles. However, in the stratified group of patients aged less than 35 years, the ORs (95% CIs, P value) of T2 and T3 were 1.316 (1.051-1.648, 0.017) and 1.354 (1.077-1.703, 0.009) for clinical pregnancy, respectively, and 1.275 (1.008-1.611, 0.043) and1.269 (0.999-1.611, 0.051) for live birth. Moreover, there was a discrepancy in the results among the subdivided LHOTD T1 groups adopting the antagonist regimen. Compared with that of the < 1.06 mIU/mL subgroup, the ORs (95% CIs, P value) of the > 1.5 mIU/mL subgroup were 1.693 (1.194-2.400, 0.003) for clinical pregnancy and 1.532 (1.057-2.220, 0.024) for live birth after eliminating potential confounders.

CONCLUSIONS

The LHOTD was profoundly suppressed in the agonist regimen, and its level was positively correlated with clinical pregnancy and live birth rates. In contrast, in the flexible antagonist regimen, the LHOTD was significantly higher than that in the agonist regimen and did not correlate with the outcome, except for women in the nonadvanced age group and those with an excessively suppressed LHOTD. Further investigation is required to determine the rationale for these findings.

Outcomes After a Single Ovarian Stimulation Cycle in Women of Advanced Reproductive Age: A Retrospective Analysis

OBJECTIVES

Previous studies showed that age is the most important factor that determines the outcome after embryo transfer (ET), with either in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI), regardless whether fresh or frozen cycles. The average cumulative live birth rate (CLBR) following a single ovarian stimulation cycle in women of advanced reproductive age (≥38 years of age) has been reported to be 22.6-34.1%. The purpose of this study is to compare the CLBR after a single ovarian stimulation cycle in women of different advanced reproductive age bracket (38/39, 40/41, 42/43 years of age or older), and to explore the factors (e.g., age, type of infertility, body mass index (BMI), ovarian stimulation protocols) associated with CLBR.

METHODS

This retrospective analysis included all women of advanced reproductive age (38 years or older) undergoing IVF or ICSI at authors' institute during a period from January 1, 2016 to December 31, 2018. The study protocol was approved by the Ethics Committee of the Second Hospital of Hebei Medical University (No. 2021-P045). Subjects with underlying diseases were excluded from analysis. The last follow-up was conducted in December 2020, with minimal 2-year follow-up.

RESULTS

The final analysis included 826 women (40.00 ± 2.10 years of age at the time of ovarian stimulation; n = 633 and 193 for IVF-ET and ICSI-ET, respectively). The number of women in each age bracket was: 424 for 38/39 y, 226 for 40/41 y, 118 for 42/43 y, and 58 for ≥44 y. The number of transferable embryos was 2 (interquartile range: 2,4) for 38/39 y, 2 (2,3) for 40/41 y, 2 (2,3) for 42/43 y, and 2 (1.75,3) for ≥44 y. The rate of fresh embryo transfer was comparable (62.03-72.58%) among the 4 age brackets. The average CLBR following a single cycle was 26.27% in the overall study population, 32.31% for 38/39 y, 26.99% for 40/41 y, 14.4% for 42/43 y, and 3.44% for ≥44 y (P <0.001). In multivariate regression, CLBR was independently associated with younger age (OR for each year: 1.538, 95%CI: 1.193, 1.984) and higher number of transferable embryos (OR for each embryo: 1.495, 95%CI: 1.297, 1.722). CLBR differed significantly in the 38/39 group (P = 0.014), with higher rate in women receiving the Gonadotropin-releasing hormone agonist (GnRH-a) long or GnRH-a ultra-long protocols.

CONCLUSIONS

Forty-two years of age seemed to be a critical cutoff to achieve reasonable level of CLBR after a single ovarian stimulation cycle in women of advanced reproductive age.

The Recurrent Mutation in PATL2 Inhibits Its Degradation Thus Causing Female Infertility Characterized by Oocyte Maturation Defect Through Regulation of the Mos-MAPK Pathway

PAT1 homolog 2 (PATL2), encoding an RNA-binding protein, is a repressor involved in the translational regulation of maternal mRNAs during oocyte maturation. Previous studies have reported mutations in PATL2 those led to female infertility with oocyte maturation arrest; however, the mechanisms by which mutations affected meiotic maturation remained unclear. Here, we identified several novel and recurrent mutations of PATL2 in patients with similar phenotype, and chose the missense mutation c.649 T>A p.Tyr217Asn in PATL2 (PATL2^Y217N) as a typical to investigate the underlying mechanisms. We confirmed that this mutation disturbed oocyte maturation and observed morphological defects of large polar body, symmetrical division and abnormal spindle after microinjection of corresponding mutated mRNA. We further evaluated the effect of the PATL2^Y217N mutation in 293T cells, and found this mutation decreased the ubiquitination level and degradation of PATL2. Then, abnormally increased PATL2 bound mRNAs of Mos, an upstream activator of mitogen activated protein kinase (MAPK), to regulate its translational activity and subsequently impaired MAPK signaling pathway and oocyte meiosis. These results dissented from the previous view that PATL2 mutations reduced their expression and highlight the role of PATL2 in translational regulation of Mos and its association with MAPK signaling pathway during oocyte meiotic maturation.

Hormonal Effects in Reproductive Technology with Focus on Diminished Ovarian Reserve

Modern use of reproductive technologies has revolutionized the treatment of infertile couples. Strategies to improve ovarian function in cases of diminished ovarian reserve are perhaps the least understood area in this field and will be the chief focus of this chapter.

Pharmacology of medications used for ovarian stimulation

Medications to stimulate the ovaries may be used to induce ovulation in patients with anovulatory infertility or to hyperstimulate the ovaries in a controlled fashion in ovulatory patients as part of assisted reproductive treatments (ART). The pharmacology of all current major medications used to stimulate ovarian function is reviewed in this article, including letrozole, clomiphene citrate, gonadotropins, and pulsatile gonadotropin releasing hormone (GnRH). Novel potential compounds and adjuvant treatment approaches are also discussed, such as kisspeptin agonists and androgens.

Efficiency of metaphase II oocytes following minimal/mild ovarian stimulation in vitro fertilization

BACKGROUND

An inverse relationship between oocyte efficiency and ovarian response was reported in conventional IVF. The purpose of this study was to report metaphase II (MII) oocyte efficiency according to oocyte yield in minimal/mild stimulation IVF (mIVF) and to assess whether oocyte yield affects live birth rate (LBR).

METHODS

Infertile women (n = 264) aged < 39 years old with normal ovarian reserve who had mIVF were recruited. All participants received the same protocol for ovarian stimulation. All the embryos were cultured to the blastocyst stage and vitrified using a freeze-all approach. This was followed by a single blastocyst transferred to each participant in subsequent cycles over a 6-month period. Ovarian response was categorized according to the number of MII oocyte yield (low: 1-2, intermediate: 3-6 and high ≥ 7 MII oocytes). MII oocyte utilization rate was calculated as the number of live births divided by the number of MII oocytes produced after only one oocyte retrieval and subsequent transfers of vitrified/warmed blastocysts. The main outcome measure was cumulative LBR over a 6-month period.

RESULTS

Among all the participants, 1173 total retrieved oocytes (4.4 ± 0.2 per patient) resulted in 1019 (3.9 ± 0.2 per patient) total MII oocytes, a clinical pregnancy rate of 48.1 % and a LBR of 41.2 %. Oocyte utilization rate was inversely related to ovarian response where it was 30.3 % in the "low" vs. 9.3 % in the "intermediate" vs. 4.3 % in the "high" oocyte yield groups (p < 0.05). Implantation rate significantly dropped as the number of MII oocytes increased and was highest in the "low" oocyte yield group (p < 0.0001). Cumulative LBR was similar in "low," "intermediate," and "high" oocyte yield groups (p > 0.05). The number of MII oocytes had poor sensitivity and specificity for predicting a live birth.

CONCLUSION

These data extend the hypothesis of oocyte efficiency reported in conventional IVF protocols to mIVF protocols.

TRIAL REGISTRATION

Registration clinicaltrials.gov: NCT00799929.

Identification of Polycystic Ovary Syndrome (PCOS) Specific Genes in Cumulus and Mural Granulosa Cells

Polycystic ovary syndrome (PCOS) is a metabolic and endocrine disorder which affects women of reproductive age with prevalence of 8–18%. The oocyte within the follicle is surrounded by cumulus cells (CCs), which connect with mural granulosa cells (MGCs) that are responsible for secreting steroid hormones. The main aim of this study is comparing gene expression profiles of MGCs and CCs in PCOS and control samples to identify PCOS-specific differentially expressed genes (DEGs). In this study, two microarray databases were searched for mRNA expression microarray studies performed with CCs and MGCs obtained from PCOS patients and control samples. Three independent studies were selected to be integrated with naive meta-analysis since raw meta-data from these studies were found to be highly correlated. DEGs in these somatic cells were identified for PCOS and control groups. This study enabled us to reveal dysregulation in MAPK (mitogen activated protein kinase), insulin and Wnt signaling pathways between CCs and MGCs in PCOS. The meta-analysis results together with qRT-PCR validations provide evidence that molecular signaling is dysregulated through MGCs and CCs in PCOS, which is important for follicle and oocyte maturation and may contribute to the pathogenesis of the syndrome.

Resurgence of Minimal Stimulation In Vitro Fertilization with A Protocol Consisting of Gonadotropin Releasing Hormone-Agonist Trigger and Vitrified-Thawed Embryo Transfer

Minimal stimulation in vitro fertilization (mini-IVF) consists of a gentle controlled ovarian stimulation that aims to produce a maximum of five to six oocytes. There is a misbelief that mini-IVF severely compromises pregnancy and live birth rates. An appraisal of the literature pertaining to studies on mini-IVF protocols was performed. The advantages of minimal stimulation protocols are reported here with a focus on the use of clomiphene citrate (CC), gonadotropin releasing hormone (GnRH) ago- nist trigger for oocyte maturation, and freeze-all embryo strategy. Literature review and the author’s own center data suggest that minimal ovarian stimulation protocols with GnRH agonist trigger and freeze-all embryo strategy along with single embryo transfer produce a reasonable clinical pregnancy and live birth rates in both good and poor responders. Additionally, mini-IVF offers numerous advantages such as: i. Reduction in cost and stress with fewer office visits, needle sticks, and ultrasounds, and ii. Reduction in the incidence of ovarian hyperstimulation syndrome (OHSS). Mini-IVF is re-emerging as a solution for some of the problems associated with conventional IVF, such as OHSS, cost, and patient discomfort.

Human embryonic poly(A)-binding protein (EPAB) alternative splicing is differentially regulated in human oocytes and embryos

Oocyte maturation is associated with suppression of transcriptional activity. Consequently, gene expression during oocyte maturation, fertilization and early embryo development, until zygotic genome activation (ZGA) is primarily regulated by translational activation of maternally derived mRNAs. Embryonic poly(A)-binding protein (EPAB) is the predominant poly(A)-binding protein in Xenopus, mouse and human oocytes and early embryos prior to ZGA. EPAB plays a key role in polyadenylation-dependent translational activation of mRNAs by stabilizing polyadenylated mRNAs and by stimulating their translation. Epab-knockout female mice are sterile, fail to generate mature oocytes and display impaired cumulus expansion and ovulation. Consistent with its role during gametogenesis and early embryo development, Xenopus and mouse Epab mRNA is expressed exclusively in oocytes and early embryos, and is undetectable following ZGA or in somatic tissues. Herein, we demonstrate that although EPAB is expressed in human somatic tissues, its transcripts largely consist of an alternatively spliced form lacking the first 58 bp of exon 8, which leads to the formation of a premature stop codon 6 amino acids downstream on exon 8, and omission of the functionally critical poly(A)-binding domain. Moreover, 8-cell and blastocyst stage human embryos also express only the alternatively spliced form of EPAB. On the other hand, the full-length form of EPAB mRNA is exclusively expressed in oocytes. In conclusion, in contrast with the transcriptional regulation in Xenopus and mouse, oocyte- and early embryo-specific expression of EPAB in human is regulated by a post-transcriptional mechanism.

Oocyte maturation failure: a syndrome of bad eggs

To show that disruption of meiotic competence results in cell cycle arrest, and the production of immature oocytes that are not capable of fertilization. Through an extensive review of animal studies and clinical case reports, we define the syndrome of oocyte maturation failure as a distinct oocyte disorder, present a classification system based on clinical parameters, and discuss the potential molecular origins for the disease.

Drug delivery for in vitro fertilization: rationale, current strategies and challenges

In vitro fertilization has experienced phenomenal progress in the last thirty years and awaits the additional refinement and enhancement of medication delivery systems. Opportunity exists for the novel delivery of gonadotropins, progesterone and other adjuvants. This review highlights the rationale for various medications, present delivery methods and introduces the status of novel ideas and possibilities.

Impact of GnRH ovarian stimulation protocols on intracytoplasmic sperm injection outcomes

BACKGROUND

Although a large number of studies have been conducted in relation to ovarian response and pregnancy after GnRH agonist and GnRH antagonist controlled ovarian hyperstimulation protocols, most of them used single or combinations of a few predictive factors, and none included the stimulation protocol in the multivariable analysis. The present study was thus primarily designed to investigate the predictive value of the stimulation protocol and to analyze the possible relationships between stimulation protocols and treatment outcomes after adjusting for a large set of variables that potentially affect reproductive outcomes. Factors related to pregnancy achievement and predictive of the number of oocytes retrieved and high quality of the embryos obtained were also analyzed.

METHODS

To analyze the impact of GnRH ovarian stimulation protocols on the independent predictors of ovarian response, high quality embryos and clinical pregnancy, two groups out of 278 ICSI treatment cycles were compared prospectively, 123 with a GnRH agonist and 155 with a GnRH antagonist, with multivariable analysis assessing outcomes after adjusting for a large set of variables.

RESULTS

Antagonists were significantly associated with lower length and total dose of GnRH, lower length of rFSH, and higher numbers of oocytes and high quality embryos, whereas the agonist presented a higher fertilization rate and probability of pregnancy. Significant predictors of retrieved oocytes and high quality embryos were the antagonist protocol, lower female age, lower serum levels of basal FSH and higher total number of antral follicles. Significant predictors of clinical pregnancy were the agonist protocol, reduced number of attempts, increased endometrial thickness and lower female age. The probability of pregnancy increased until 30 years-old, with a decline after that age and with a sharp decline after 40 years-old.

CONCLUSION

The models found suggest that not only the protocol but also factors as female age, basal FSH, antral follicles, number of attempts and endometrial thickness should be analyzed for counselling patients undergoing an ICSI treatment.

Effect of GnRH down-regulation on cumulus cell viability and apoptosis as measured by fluorescence-activated cell sorting

OBJECTIVE

To determine whether gonadotropin releasing hormone (GnRH)-agonist or -antagonist induces higher percentages of cumulus cell apoptosis and if the use of either is detrimental to ART outcomes.

PATIENTS

Women in a private facility under treatment for IVF had their cumulus cells isolated and analyzed by flow cytometry. Viable, apoptotic, and dead cumulus cell rates related to ovarian stimulation by GnRH-agonist or -antagonist were measured and compared with fertilization and implantation rates.

RESULTS

Treatment with GnRH-agonist produced a greater number of follicles than treatment with GnRH-antagonist. No differences in implantation and pregnancy rates were found. While cumulus cell (CC) apoptosis was positively correlated with estradiol on the day of hCG administration, no significant difference in the percentage of apoptotic cells between treatments was detectable. Additionally, implantation rate and the average follicular estradiol production on the day of hCG administration were no different between treatments.

CONCLUSIONS

GnRH-agonist or -antagonist treatment protocols induce similar levels of apoptosis in CCs and are not detrimental to ART outcomes.

Noninvasive metabolomic profiling of embryo culture media using proton nuclear magnetic resonance correlates with reproductive potential of embryos in women undergoing in vitro fertilization

OBJECTIVE

To identify biomarkers associated with reproductive outcome using proton nuclear magnetic resonance ((1)H NMR) metabolomic profiling of embryo culture media.

DESIGN

Retrospective study.

SETTING

An academic assisted reproductive technology (ART) program; a university research center.

PATIENT(S)

Women undergoing ART treatment.

INTERVENTION(S)

Spent media samples from embryos that resulted in pregnancy and delivery (n = 17) and samples (n = 17) from embryos that failed to implant were individually collected on day 3, and evaluated using (1)H NMR spectroscopy. The spectra obtained were quantified by integrating six biomarker signals in the aliphatic region after baseline subtraction. Using a multivariate analysis, a model that calculates a viability index for each spectrum was developed. Sensitivity and specificity of predicting pregnancy (described as implantation and delivery) were calculated.

MAIN OUTCOME MEASURE(S)

The (1)H NMR metabolomic profile of embryo culture media and embryo viability.

RESULT(S)

Glutamate concentrations determined by (1)H NMR were significantly higher in spent culture media of embryos that resulted in pregnancy and delivery compared to those that failed to implant. Similarly, viability indices calculated by (1)H NMR using the weighted coefficients of glutamate and alanine/lactate ratio quantities were higher for embryos that implanted and resulted in a delivery. Proton NMR spectroscopy predicted viability of individual embryos with a sensitivity of 88.2% and a specificity of 88.2%.

CONCLUSION(S)

Metabolomic profile of spent embryo culture media using (1)H NMR correlates with the reproductive potential of embryos.

Serum cetrorelix concentrations do not affect clinical pregnancy outcome in assisted reproduction

OBJECTIVE

To analyze the potential association between serum cetrorelix levels and clinical pregnancy outcome in patients who had undergone assisted reproduction cycles with a GnRH antagonist cetrorelix acetate 3-mg injection.

DESIGN

Retrospective case-control study.

SETTING

University-affiliated private-assisted reproduction center.

PATIENT(S)

130 IVF and intracytoplasmic sperm injection first cycles, treated with the same cetrorelix acetate protocol, in two matched groups according to whether the cycle resulted in clinical pregnancy (n = 56) or not (n = 74).

INTERVENTION(S)

Cetrorelix acetate administration at 3 mg in a sandwich protocol.

MAIN OUTCOME MEASURE(S)

Serum cetrorelix concentrations on the day of hCG administration with regard to clinical pregnancy outcome, pre- versus post-hCG percent change in serum E(2) levels and implantation rates.

RESULT(S)

The cetrorelix serum concentrations were in the range of 0.29 to 5.12 ng/mL. The comparisons between groups with and without clinical pregnancy revealed comparable serum cetrorelix levels. There was no significant correlation between the serum cetrorelix concentrations and percent change in pre- versus post-hCG serum E(2) levels. Serum cetrorelix levels were comparable among patients with various implantation rates.

CONCLUSION(S)

Although a wide range of serum cetrorelix levels could be detected during a GnRH antagonist cycle, these levels were comparable in patients with and without clinical pregnancies.

Recombinant-follicle stimulating hormone is more effective than urinary human menopausal gonadotropin in ovarian hyperstimulation for assisted reproductive technology treatment

Aim:  The aim of the present study was to establish a standard protocol for ovarian stimulation with gonadotropin-releasing hormone analog (GnRH-a) long protocol using recombinant-follicle stimulating hormone (rec-FSH) preparations for assisted reproductive technology (ART) treatment. Methods:  In 86 patients who underwent ovarian stimulation with GnRH-a long protocol for ART treatment, 53 were stimulated by rec-FSH preparations (rec-FSH group) and the others were stimulated by urinary-hMG (u-hMG group) preparations. The subjects were randomly assigned to either of these preparations. Hormonal profiles, total doses of gonadotropins, duration of stimulation and ART results were compared in both groups. Results:  The duration of stimulation was similar in both groups (9.2 ± 0.3 days and 9.2 ± 0.2 days, respectively). The total doses of gonadotropin in the rec-FSH group (1505.3 ± 29.2 IU) was significantly lower than those in the u-hMG group (2130.3 ± 54.6 IU, P < 0.0001). The FSH and LH values on the day of human chorionic gonadotropin (hCG) administration in the rec-FSH group were significantly lower than those in the u-hMG group. Pregnancy rates were 31.3% in the rec-FSH group and 33.3% in the u-hMG group, respectively. Conclusions:  The present study showed that rec-FSH preparations were more potent than conventional u-hMG preparations and the protocol of the present study with rec-FSH was a new ovarian stimulation protocol with GnRH-a long protocol. (Reprod Med Biol 2007; 6: 27-32).

Reluctance of medical professionals in adopting natural-cycle and minimal ovarian stimulation protocols in human clinical assisted reproduction

Recent clinical evidence would suggest that natural cycle and minimal ovarian stimulation protocols in clinical assisted reproduction could be advantageous for younger women with indications for either male-partner or mild female-factor subfertility. The benefits include reduced medical fees associated with lower or nil dosages of recombinant gonadotrophins, a shorter treatment cycle and reduced risk of ovarian hyperstimulation syndrome. Additionally, there is also evidence to suggest improved quality of retrieved oocytes and better endometrial receptivity. Nevertheless, fertility clinics and doctors have conflicting interests that make them reluctant to incorporate natural-cycle and minimal stimulation protocols in their treatment programme. Firstly, the use of low or nil dosages of recombinant gonadotrophins would drastically cut profits from drug prescription sales to patients. Secondly, fertility clinics are also concerned by the apparent reduction in success rates for natural-cycle and minimal ovarian stimulation protocols. Moreover, refunding of medical bills by health insurance is usually based on a limited number of attempts, thereby hampering the introduction of natural-cycle and minimal stimulation protocols, which have lower efficacy on a per cycle basis. Lastly, the adoption of natural-cycle and minimal stimulation protocols would drastically reduce the numbers of surplus oocytes and embryos available for donation to other patients.

Embryo transfer and luteal support in natural cycles

Embryo transfer policy and luteal supplementation was reviewed, comparing literature data and the results from the Maribor IVF Centre. A retrospective analysis of 1024 cycles in patients undergoing IVF, intracytoplasmic sperm injection (ICSI) or testicular sperm aspiration in unstimulated cycles was carried out using four different approaches for cycle monitoring. This showed that the most successful protocol for monitoring was administration of human chorionic gonadotrophin (HCG) when serum oestradiol was >0.49 nmol/l and follicle diameter was at least 15 mm. The implantation rate per transferred embryo was higher when a blastocyst was transferred (42.8%) rather than a day-2 embryo (23.5%) in the same monitoring protocol. Analysis of the influence of patient age on the success of oocyte retrieval, oocyte fertilization, embryo transfer rate and delivery rate demonstrates that patient age does not influence the rate of positive oocyte retrieval or fertilization rate as much as it influences pregnancy rate per embryo transfer. The delivery rate per cycle was dramatically influenced by age in patients over 38 years. There is no clear evidence in the literature as to whether luteal phase support is necessary in natural cycles for IVF/ICSI. Comparing the data, a higher pregnancy rate was observed if HCG was administered after embryo transfer.

Cetrorelix in the treatment of female infertility and endometriosis

The use of cetrorelix within ovarian-stimulation protocols demonstrates several advantages compared with gonadotropin-releasing hormone (GnRH) agonist-containing protocols, which include, for example, significantly less time for analogue treatment and a reduction in the amount of gonadotropins needed. Furthermore, fewer side effects can be expected. There is no difference regarding endometrium quality and hormone profiles, and the results of assisted reproduction cycles are comparable. Cetrorelix also seems to be useful in the treatment of endometriosis which, in most cases, is an estrogen-dependent disease. Furthermore, fewer side effects occur with this agent (e.g., postmenopausal symptoms) and no estradiol add-back is needed. In the future, new nonpeptic GnRH antagonists are expected to be available for oral administration. Although they are still under investigation, these agents have the potential to improve patients' comfort and compliance.

Screening for hereditary hemochromatosis: a clinical practice guideline from the American College of Physicians

Hereditary hemochromatosis is a genetic disorder of iron metabolism. Diagnosis of hereditary hemochromatosis is usually based on a combination of various genetic or phenotypic criteria. Decisions regarding screening are difficult because of the variable penetrance of mutations of the HFE gene and the absence of any definitive trials addressing the benefits and risks of therapeutic phlebotomy in asymptomatic patients or those with only laboratory abnormalities. The purpose of this guideline is to increase physician awareness of hereditary hemochromatosis, particularly the variable penetrance of genetic mutations; aid in case finding; and explain the role of genetic testing. This guideline provides recommendations based on a review of evidence in the accompanying background paper by Schmitt and colleagues. The target audience for this guideline is internists and other primary care physicians. The target patient population is all persons who have a probability or susceptibility of developing hereditary hemochromatosis, including the relatives of individuals who already have the disease.