Clinical parameters that predict a premature LH rise in patients undergoing ovarian stimulation for IVF.

Background: Normal reproductive function requires adequate regulation of follicle stimulating hormone (FSH) and luteinizing hormone (LH) secretion. During ovarian stimulation for in-vitro fertilization (IVF), some patients will demonstrate an early rise in LH despite being treated with a gonadotropin releasing-hormone (GnRH) antagonist, sometimes necessitating cycle cancellation. Previous studies have demonstrated a possible link between a premature LH rise with ovarian response to gonadotropins. We sought to determine what clinical parameters can predict this premature LH rise and their relative contribution. Methods: A retrospective study of 382 patients who underwent IVF treatment at Rambam Medical Center. The patients were stratified into age groups. A model predicting premature LH rise based on clinical and demographic parameters was developed using both multiple linear regression and a machine-learning-based algorithm. Results: LH rise was defined as the difference between pre-trigger and basal LH levels. The clinical parameters that significantly predicted an LH rise were patient age, BMI, LH levels at stimulation outset, LH levels on day of antagonist administration, and total number of stimulation days. Importantly, when analyzing the data of specific age groups, the model's prediction was strongest in young patients (age 25-30 years, R2 = 0.88, p < .001) and weakest in older patients (age > 41 years, R2 = 0.23, p = .003). Conclusions: Using both multiple linear regression and a machine-learning-based algorithm of patient data from IVF cycles, we were able to predict patients at risk for premature LH rise and/or LH surge. Utilizing this model may help prevent IVF cycle cancellation and better timing of ovulation triggering.

In vitro fertilization results of GNRH antagonists and medroxyprogesterone acetate used to prevent premature LH surge during ovarian hyperstimulation.

The aim of this study was to evaluate the effects of medroxyprogesterone acetate (MPA) treatment in comparison to those of gonadotropin releasing hormone (GnRH) antagonists for the prevention of premature luteinizing hormone surges during controlled ovarian hyperstimulation (OS) and the impact of these effects on developing embryos and pregnancy outcomes. Data from 757 cycles of GnRH antagonist treatment and 756 cycles of MPA treatment were evaluated at the Akdeniz University Faculty of Medicine Assisted Reproductive Treatment Center between October 2018 and April 2022. Patient records were obtained from the electronic database of the centre and analysed. In our centre, GnRH antagonist protocols were used between 2018 and 2020, and MPA protocols were used between 2020 and 2022. We chose our study population by year. Our study is a comparative retrospective study. All methods in this study were performed in accordance with the relevant guidelines and regulations. Patients using MPA were significantly older (33.9 ± 5.6 vs. 32.6 ± 5.6, p < 0.001) and had a lower number of antral follicles (AFC) (10.7 ± 8.6 vs. 11.9 ± 10.8, p = 0.007) than those using GnRH antagonists. Both MPA (2.9%) and GnRH antagonists (2.2%) had similar effectiveness in preventing premature ovulation (p = 0.415). There was no significant difference between the two groups in terms of the number of total developed embryos (1.3 ± 1.3 vs. 1.2 ± 1.2, p = 0.765). There was no significant difference in the clinical pregnancy rates with the first ET (%35.4 vs. %30.1, p = 0.074), per total number of transfers (35.3% vs. 30.1%, p = 0.077). MPA was found to be effective at preventing premature ovulation during OS treatment, and the incidence of developing embryo and pregnancy outcomes in patients using MPA were similar to those in patients using GnRH antagonists. Therefore, the use of MPA instead of GnRH antagonists during OS may be a viable alternative for patients not scheduled for fresh ET.

Vaginal micronized progesterone on preventing luteinizing hormone untimely surge in ART cycles: A prospective proof-of-concept study.

OBJECTIVE: A new approach to evaluate whether Progestin-Primed Ovarian Stimulation with micronized vaginal progesterone was as effective as using dydrogesterone in suppress LH pulse surge in young women under stimulation in an oocyte donor programme. METHODS: This prospective study included 21 patients aged 19 to 32 years-old stimulated with Elonva® 150, associated or not with Menopur® or Merional® (75 or 150IU) since the beginning of the cycle, plus HMG 150-225IU after the 8th day or just HMG 150-300IU per day. Patients were placed in a PPOS protocol with micronized vaginal progesterone (MVP) 200 mg (Gynpro® Exeltis or Junno Farmoquimica) every 12 hours or dydrogesterone (Duphaston® Abbott) 10 mg every 8 hours from the start of stimulation until the day after the GnRH trigger with Triptorelin 0.2 mg (Gonapeptyl daily®). The primary endpoint was the prevention of untimely LH surge, and secondarily the number of 16 mm follicles, retrieved oocytes and metafase II. RESULTS: Fourteen oocyte donor patients were prescribed MVP while seven others received dydrogesterone (DYG).The gonadotropin protocols included 04 with Corifollitropin alfa 150 plus HMG since the beginning and complemented after the 7th day, and 17 times of just HMG. There was no diferences in the number of follicles >10≤15mm, ≥16mm or number of metafase II oocytes. There was no untimely LH surge on both groups and no OHSS was developed after the agonist trigger. CONCLUSIONS: Progestin-Primed Ovarian Stimulation with micronized vaginal progesterone seems to be a compelling choice for preventing premature ovulation without compromising oocyte quality in women undergoing ovarian stimulation.

The role of neuroestrogens in the estrogen-induced gonadotropin surge in male monkeys.

Neuroestrogens locally synthesized in the brain are known to play a role in sexual behaviors. However, the question of whether neuroestrogens are involved in the regulation of the gonadotropin-releasing hormone (GnRH) release is just emerging. Because previous studies in this lab indicate that neuroestradiol is also important for the pulsatile release as well as the surge release of GnRH in female rhesus monkeys, in the present study, we examined whether neuroestradiol plays a role in the estrogen-induced LH surge in orchidectomized (ORX) male rhesus monkeys. Unlike in rodents, it is known that a high dose of estrogen treatment can result in the LH surge in ORX male rhesus monkeys. Results that the administration of the aromatase inhibitor, letrozole, failed to attenuate the estrogen-induced LH surge, suggest that unlike in ovariectomized females, neuroestrogens do not play a role in the LH surge experimentally induced by the exogenous estrogen treatment in ORX male monkeys.

Neuroendocrine effects of the duper mutation in Syrian hamsters: a role for Cryptochrome 1.

Molecular and physiological determinants of the timing of reproductive events, including the pre-ovulatory LH surge and seasonal fluctuations in fertility, are incompletely understood. We used the Cryptochrome 1-deficient duper mutant to examine the role of this core circadian clock gene in Syrian hamsters. We find that the phase of the LH surge and its stability upon shifts of the light: dark cycle are altered in duper mutants. The intensity of immunoreactive PER1 in GnRH cells of the preoptic area peaks earlier in the day in duper than wild type hamsters. We note that GnRH fibers coursing through the suprachiasmatic nucleus (SCN) contact vasopressin- and VIP-immunoreactive cells, suggesting a possible locus of circadian control of the LH surge. Unlike wild types, duper hamsters do not regress their gonads within 8 weeks of constant darkness, despite evidence of melatonin secretion during the subjective night. In light of the finding that the duper allele is a stop codon in Cryptochrome 1, our results suggest important neuroendocrine functions of this core circadian clock gene.

Measurement of luteinizing hormone surge in vaginal discharge: a potential biomarker that enables simple, non-invasive prediction of the periovulatory period.

BACKGROUND: Predicting the periovulatory period is very important for conception. Current approaches to predicting the periovulatory period include monitoring of basal body temperature and urine luteinizing hormone (LH) concentration; however, these methods are time-consuming. Here, we examined the potential of using vaginal discharge (VD) as a non-invasive means of sample collection for determining the LH surge that indicates ovulation. METHODS: Urine and VD samples were collected from 35 healthy women aged 20-39 years. VD samples were collected with panty liners to reduce the burden on participants. Daily first urine samples and used panty liners were collected from the 10th through 19th days of the menstrual cycle. Urine and VD LH (uLH and vLH) levels in the samples were measured by enzyme-linked immunosorbent assay. Measured vLH baseline and first surge values were analyzed using Student's t-test and ROC curves. RESULTS: Samples for a total of 55 menstrual cycles were collected. We used uLH surge to establish the date of ovulation. uLH surges were observed in 49 cycles, 34 of which had corresponding VD samples that qualified for measurement. Five cycles were excluded due to a lack of vLH data. In the remaining 29 cycles, the vLH surge appeared within the fertile window 90% of the time, and the sensitivity and specificity of the test were 86% and 83%, respectively. CONCLUSIONS: VD has potential for use as a sample for predicting the periovulatory period by measuring LH content.

Kisspeptin and neurokinin B neuroendocrine pathways in the control of human ovulation.

The roles of initially kisspeptin and subsequently neurokinin B pathways in the regulation of human reproduction through the control of GnRH secretion were first identified 20 years ago, as essential for the onset of puberty in both boys and girls. Within that short time we already now have the first licence for clinical use for a neurokinin antagonist in a related indication, for menopausal vasomotor symptoms. Between these two markers of the start and end of the reproductive lifespan, it is clear that these pathways underlie many of the aspects of the hypothalamic regulation of reproduction which had hitherto been enigmatic. In this review, we describe the data currently available from studies designed to elucidate the roles of kisspeptin and neurokinin B in human ovarian function, specifically the regulation of follicle development leading up to ovulation, and in the control of the mid-cycle GnRH/LH surge that triggers ovulation. These studies, undertaken with only very limited pharmacological tools, provide evidence that the neurokinin B pathway is important in controlling the hypothalamic contribution to the precise gonadotropic drive to the ovary that is necessary for mono-ovulation, whereas the switch from negative to positive estrogenic feedback results in kisspeptin-mediated increased GnRH secretion. Potential therapeutic opportunities in conditions characterised by disordered hypothalamic/pituitary function, polycystic ovary syndrome, and functional hypothalamic amenorrhoea, and in the induced LH surge that is a necessary part of IVF treatment are discussed.

Comparison of progesterone protocol versus gonadotropin-releasing hormone antagonist protocol in terms of preventing premature LH surge and assisted reproductive technology outcome in infertile women: a randomized controlled trial.

INTRODUCTION: Progesterone can be used instead of GnRH agonists and antagonists in order to avert a premature LH surge during controlled ovarian stimulation (COS) protocol. Nonetheless, there is limited knowledge regarding its utilization. Thus, this study compared the effects of progesterone and GnRH antagonists (GnRH-ant) on premature LH surges and assisted reproductive technology (ART) results in infertile women undergoing ART. MATERIALS AND METHODS: In this clinical trial, the progesterone protocol (study group) and GnRH-ant protocol (control group) were tested in 300 infertile individuals undergoing IVF/ICSI. The main outcome was the number of oocytes retrieved. The secondary outcomes included premature LH rise/surge, the quantity of follicles measuring ≥ 10 and 14 mm, oocyte maturity and fertilization rate, the number of viable embryos, high-quality embryo rate and pregnancy outcomes. RESULTS: The study group exhibited a statistically significant increase in the number of retrieved oocytes, follicles measuring 14 mm or greater, and viable embryos compared to the control group (P < 0.05). The study group also increased oocyte maturity, chemical pregnancy rate, and clinical pregnancy rate (P < 0.05). Both groups had similar mean serum LH, progesterone, and E2 levels on trigger day. The control group had more premature LH rise than the study group, although this difference was not statistically significant. CONCLUSION: In conclusion, it can be stated that the progesterone protocol and the GnRH-ant protocol exhibit similar rates of sudden premature LH surge in infertile patients. However, it is important to note that the two regiments differ in their outcomes in ART. TRIAL REGISTRATION: This study was retrospectively registered in the Iranian website ( www.irct.ir ) for clinical trials registration ( http://www.irct.ir : IRCT-ID: IRCT20201029049183N, 2020-11-27).

No association between LH levels and ovarian response in oocyte donors triggered with gonadotropin-releasing hormone agonist: A prospective study.

OBJECTIVE: Are circulating luteinizing hormone (LH) levels predictive of ovarian response in oocyte donors triggered with gonadotropin-releasing hormone (GnRH) agonists? STUDY DESIGN: A prospective cohort study with 224 oocyte donation cycles between 2021 and 2022 at a single center, examined the relationship between circulating luteinizing hormone (LH) levels and ovarian response. Oocyte donors underwent GnRH antagonist downregulation followed by GnRH agonist trigger. LH, estradiol, and progesterone levels were measured on day one of stimulation, trigger-day and 12 h post-trigger. Oocyte retrieval and maturity rates were analyzed using univariate and multivariate analyses, and the correlation between post-trigger LH levels and outcomes was assessed by Pearson's correlation test. A significance level of p < 0.05 was used. RESULTS: Mean age was 26 ± 4.3 years, mean body mass index (BMI, kg/m2) was 22.6 ± 3.2 and mean antral follicle count (AFC) was 21.7 ± 8.2. Post-trigger LH levels averaged 51.3 IU/L (SD 34.8), and oocyte retrieval rate and maturity rates were 112,7% (+/-48,1%) and 77,8% (+/- 17,2%), respectively. No significant differences were found in these outcomes for donors with post-trigger LH values below and above 15 IU/L (Mann Whitney's p > 0.05). However, exploratory analyses revealed that post-trigger LH values < 22 IU/L and basal LH levels < 4 IU/L were associated with significantly lower oocyte retrieval rate (90 % vs 110 %, p = 0.019 and 100 % vs 110 %, p = 0.019, respectively). CONCLUSIONS: This study, a first in exclusively focusing on oocyte donors, did not support the previously reported LH value of 15 IU/L as predictive of suboptimal ovarian response. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Identifier: NCT05109403.

Chronic estradiol exposure suppresses luteinizing hormone surge without affecting kisspeptin neurons and estrogen receptor alpha in anteroventral periventricular nucleus†.

Mammalian ovulation is induced by a luteinizing hormone surge, which is triggered by elevated plasma estrogen levels; however, chronic exposure to high levels of estradiol is known to inhibit luteinizing hormone secretion. In the present study, we hypothesized that the inhibition of the luteinizing hormone surge by chronic estradiol exposure is due to the downregulation of the estrogen receptor alpha in kisspeptin neurons at hypothalamic anteroventral periventricular nucleus, which is known as the gonadotropin-releasing hormone/luteinizing hormone surge generator. Animals exposed to estradiol for 2 days showed an luteinizing hormone surge, whereas those exposed for 14 days showed a significant suppression of luteinizing hormone. Chronic estradiol exposure did not affect the number of kisspeptin neurons and the percentage of kisspeptin neurons with estrogen receptor alpha or c-Fos in anteroventral periventricular nucleus, but it did affect the number of kisspeptin neurons in arcuate nucleus. Furthermore, chronic estradiol exposure did not affect gonadotropin-releasing hormone neurons. In the pituitary, 14-day estradiol exposure significantly reduced the expression of Lhb mRNA and LHß-immunoreactive areas. Gonadotropin-releasing hormone-induced luteinizing hormone release was also reduced significantly by 14-day estradiol exposure. We revealed that the suppression of an luteinizing hormone surge by chronic estradiol exposure was induced in association with the significant reduction in kisspeptin neurons in arcuate nucleus, luteinizing hormone expression in the pituitary, and pituitary responsiveness to gonadotropin-releasing hormone, and this was not caused by changes in the estrogen receptor alpha-expressing kisspeptin neurons in anteroventral periventricular nucleus and gonadotropin-releasing hormone neurons, which are responsible for estradiol positive feedback.

Ovarian Stimulation with FSH Alone versus FSH plus a GnRH Antagonist for Elective Freezing in an Oocyte Donor/Recipient Programme: A Protocol for a Pilot Multicenter Observational Study.

Preliminary data have shown that it is possible to attempt in vitro fertilization (IVF) treatment in fresh cycles without the use of a gonadotropin-releasing hormone (GnRH) antagonist or any other medication to prevent the luteinizing hormone (LH) surge during ovarian stimulation. To date, there is no information on this topic in the context of a prospective controlled trial. However, as prevention of the LH surge is an established procedure in fresh cycles, the question is whether such a study can be performed in frozen cycles. We aim to perform a pilot study in order to compare the efficacy of a protocol using FSH alone with that of a protocol using follicle-stimulating hormone (FSH) plus a GnRH antagonist for controlled ovarian hyperstimulation (COH) in cycles of elective freezing in the context of a donor/recipient program. This is a seven-center, two-arm prospective pilot cohort study conducted at the respective Assisted Reproductive Units in Greece. The hypothesis to be tested is that an ovarian stimulation protocol that includes FSH alone without any LH surge prevention regimens is not inferior to a protocol including FSH plus a GnRH antagonist in terms of the clinical outcome in a donor/recipient model. The results of the present study are expected to show whether the addition of the GnRH antagonist is necessary in terms of the frequency of LH secretory peaks and progesterone elevations >1 ng/mL during the administration of the GnRH antagonist according to the adopted frequency of blood sampling in all Units.

Hindbrain Adenosine 5-Triphosphate (ATP)-Purinergic Signaling Triggers LH Surge and Ovulation via Activation of AVPV Kisspeptin Neurons in Rats.

Ovulation disorders are a serious problem for humans and livestock. In female rodents, kisspeptin neurons in the anteroventral periventricular nucleus (AVPV) are responsible for generating a luteinizing hormone (LH) surge and consequent ovulation. Here, we report that adenosine 5-triphosphate (ATP), a purinergic receptor ligand, is a possible neurotransmitter that stimulates AVPV kisspeptin neurons to induce an LH surge and consequent ovulation in rodents. Administration of an ATP receptor antagonist (PPADS) into the AVPV blocked the LH surge in ovariectomized (OVX) rats treated with a proestrous level of estrogen (OVX + high E2) and significantly reduced the ovulation rate in proestrous ovary-intact rats. AVPV ATP administration induced a surge-like LH increase in OVX + high E2 rats in the morning. Importantly, AVPV ATP administration could not induce the LH increase in Kiss1 KO rats. Furthermore, ATP significantly increased intracellular Ca2+ levels in immortalized kisspeptin neuronal cell line, and coadministration of PPADS blocked the ATP-induced Ca2+ increase. Histologic analysis revealed that the proestrous level of estrogen significantly increased the number of P2X2 receptor (an ATP receptor)-immunopositive AVPV kisspeptin neurons visualized by tdTomato in Kiss1-tdTomato rats. The proestrous level of estrogen significantly increased varicosity-like vesicular nucleotide transporter (a purinergic marker)-immunopositive fibers projecting to the vicinity of AVPV kisspeptin neurons. Furthermore, we found that some hindbrain vesicular nucleotide transporter-positive neurons projected to the AVPV and expressed estrogen receptor α, and the neurons were activated by the high E2 treatment. These results suggest that hindbrain ATP-purinergic signaling triggers ovulation via activation of AVPV kisspeptin neurons.SIGNIFICANCE STATEMENT Ovulation disorders, which cause infertility and low pregnancy rates, are a serious problem for humans and livestock. The present study provides evidence that adenosine 5-triphosphate, acting as a neurotransmitter in the brain, stimulates kisspeptin neurons in the anteroventral periventricular nucleus, known as the gonadotropin-releasing hormone surge generator, via purinergic receptors to induce the gonadotropin-releasing hormone/luteinizing hormone surge and ovulation in rats. In addition, histologic analyses indicate that adenosine 5-triphosphate is likely to be originated from the purinergic neurons in the A1 and A2 of the hindbrain. These findings may contribute to new therapeutic controls for hypothalamic ovulation disorders in humans and livestock.

Medroxyprogesterone Acetate versus Gonadotropin-Releasing Hormone Antagonist for the Prevention of Premature Luteinizing Hormone Surge in hyper-responder women undergoing controlled ovarian stimulation for IVF/ICSI Cycles.

OBJECTIVE: To compare the effect of Medroxyprogesterone acetate versus Gonadotropin releasing hormone antagonist for the prevention of premature luteinizing hormone (LH) surge in infertile hyper-responder women undergoing controlled ovarian stimulation for in vitro fertilization (IVF) /intracytoplasmic sperm injection (ICSI) cycles. METHODS: One hundred infertile hyper-responder women who were candidate for IVF/ICSI were randomly assigned into two groups. Group 1 was given 20 mg Medroxyprogesterone acetate from day 1 of the menstrual cycle till trigger day. Group 2 was given GnRH antagonist (injection Cetrorelix 0.25 mg s/c) from the day when the leading follicle reached 14 mm until the day of trigger for the prevention of premature LH surge (flexible protocol). We measured LH serum levels on day 1, day 7 of cycle and on trigger day. The primary outcome measured was the incidence of premature LH surge. Other outcome measures were total number of mature follicles on trigger day, total number of mature oocytes retrieved and number of good quality day-3 embryos. RESULTS: There was no premature luteinizing hormone surge in both groups of our study. The mean number of follicles on trigger day, mean number of M2 oocytes retrieved and mean number of good quality day-3 embryos were comparable in both the groups, with no statistically significant difference. CONCLUSIONS: The results of this study stated that MPA can be an effective alternative to GnRH antagonist for the prevention of premature LH surge in hyper-responder women undergoing COS for IVF. It is easy to use, widely available and cost-effective. It may establish a new regimen of ovarian stimulation using MPA as an oral alternative to GnRH antagonist treatment in hyper-responders.

Successful pregnancy outcome after fresh embryo transfer in a dual stimulation cycle - a case report.

Controlled ovarian stimulation by antagonist protocol sometimes presents unpleasant surprises in the form of unexpected premature rupture of follicles despite well-timed daily administration of the antagonist. In such cases ovum pick up cannot be done, dual stimulation of the next crop of follicles may be pursued to salvage the cycle. A 'freeze all' strategy is usually implemented in all cases of dual stimulation because of embryo-endometrial asynchrony. Here we present a case where dual stimulation was followed by fresh embryo transfer with a successful pregnancy outcome.

Progestin-primed ovarian stimulation versus GnRH antagonist protocol in poor responders: Risk of premature LH surge and outcome of oocyte retrieval.

PURPOSE: For poor ovarian responders (PORs), gonadotropin-releasing hormone (GnRH) antagonist was commonly used for prevention of premature LH surge during controlled ovarian stimulation (COS) over the past two decades. The application of progestin-primed ovarian stimulation (PPOS) recently increased, but the role of PPOS for PORs was uncertain. We aimed to analyze the incidence of premature luteinizing hormone (LH) surge and the outcome of oocyte retrieval among PPOS and GnRH antagonist protocol for PORs. METHODS: This was a single-center retrospective study, which enrolled the PORs (defined by the Bologna criteria) undergoing COS with PPOS or flexible GnRH antagonist protocol during January 2018 to December 2021. We compared the incidence of premature LH surge (LH > 10 mIU/mL) and the outcome of oocyte retrieval between the PPOS group and the GnRH antagonist group. RESULTS: A total of 314 women were recruited, with 54 in the PPOS group and 260 in the GnRH antagonist group. The PPOS group had lower incidence of premature LH surges compared with the GnRH antagonist protocol group (5.6% vs 16.9%, P value 0.035). There was no significant difference between the two groups regarding the number of oocytes retrieved (3.4 vs 3.8, P value 0.066) and oocyte retrieval rates (88.9% vs 88.0%, P value 0.711). CONCLUSION: Compared with PPOS, GnRH antagonist protocol had higher risk of premature LH surges for PORs but may not affect pregnancy rates. PPOS is suitable for oocyte or embryo cryopreservation, but should not totally replace GnRH antagonist protocol for patients undergoing in vitro fertilization (IVF).

Preventing Growth Stagnation and Premature LH Surge Are the Keys to Obtaining a Viable Embryo in Monofollicular IVF Cycles: A Retrospective Cohort Study.

How LH levels influenced the outcomes of monofollicular IVF cycles using different stimulation protocols was controversial. In this single-center, retrospective study, we analyzed 815 monofollicular IVF cycles between 2016−2022 using natural cycle (NC), medroxyprogesterone acetate (MPA) or clomiphene citrate (CC) in addition to human menopausal gonadotropin (hMG), with or without GnRH antagonist. A viable embryo was obtained in 35.7% of all cycles. Growth stagnation and premature LH surge are two markedly negative factors for obtaining viable embryos (odds ratios of 0.12 [0.08−0.65], p < 0.0001 and 0.33 [0.26,0.42], p < 0.0001, respectively). NC/hMG cycles are prone to premature LH surge (40.4%), yielding a significantly lower opportunity of obtaining embryos (24.7%, p = 0.029). The administration of GnRH antagonist on the background of MPA resulted in a significant decrease in LH levels (from 2.26 IU/L to −0.89 IU/L relative to baseline, p = 0.000214), leading to a higher risk of growth stagnation (18.6%, p = 0.007). We hypothesized that the abrupt decline of LH might increase the risk of apoptosis in granulosa cells. We proposed a "marginal effect" framework to emphasize that the change of LH was the key to its bioactivity, rather than the traditional "window" concept with fixed cutoff values of a threshold and a ceiling.

Frozen-thawed embryo transfer in modified natural cycles: a retrospective analysis of pregnancy outcomes in ovulatory women with vs. without spontaneous luteinizing hormone surge.

BACKGROUND: Timing of frozen embryo transfer (FET) in natural endometrial preparation cycles is often based on luteinizing hormone (LH) surge. However, some patients do not show spontaneous LH surge despite follicular maturation. The objective of this study was to evaluate the impact of spontaneous LH surge on pregnancy outcomes in modified natural cycles (mNC). METHODS: This retrospective analysis included 1897 FET cycles with modified natural endometrial preparation in normo-ovulatory women between January 1, 2015, to December 31, 2019, at our center: 920 cycles with spontaneous LH surge (≥ 20 IU/L) and 977 without. For cleavage embryos, FET was conducted 4 and 5 days after hCG injection in women with and without LH surge, respectively. For blastocysts, FET was conducted 6 and 7 days after hCG injection in women with and without LH surge, respectively. Multivariate regression was conducted to examine the factors associated with live birth. RESULTS: Live birth rate was 43.7% in patients with spontaneous LH surge vs. 43.8% in women without LH surge (P = 0.961). The two groups also had similar implantation rate (36.2% vs. 36.7%, P = 0.772), biochemical pregnancy rate (54.8% vs. 55.4%, P = 0.796) and clinical pregnancy rate (50.9% vs. 51.7%, P = 0.721). In multivariate regression, live birth was not associated with LH surge (aOR, 0.947, 95% CI, 0.769, 1.166). CONCLUSION: Pregnancy outcomes were similar in mNC-FET in cycles with vs. without spontaneous LH surge if FET timing is adjusted.

Mistimed restricted feeding disrupts circadian rhythms of male mating behavior and female preovulatory LH surges in mice.

In rodents, eating at atypical circadian times, such as during the biological rest phase when feeding is normally minimal, reduces fertility. Prior findings suggest this fertility impairment is due, at least in part, to reduced mating success. However, the physiological and behavioral mechanisms underlying this reproductive suppression are not known. In the present study, we tested the hypothesis that mistimed feeding-induced infertility is due to a disruption in the normal circadian timing of mating behavior and/or the generation of pre-ovulatory luteinizing hormone (LH) surges (estrogen positive feedback). In the first experiment, male+female mouse pairs, acclimated to be food restricted to either the light (mistimed feeding) or dark (control feeding) phase, were scored for mounting frequency and ejaculations over 96 h. Male mounting behavior and ejaculations were distributed much more widely across the day in light-fed mice than in dark-fed controls and fewer light-fed males ejaculated. In the second experiment, the timing of the LH surge, a well characterized circadian event driven by estradiol (E2) and the SCN, was analyzed from serial blood samples taken from ovariectomized and E2-primed female mice that were light-, dark-, or ad-lib-fed. LH concentrations peaked 2 h after lights-off in both dark-fed and ad-lib control females, as expected, but not in light-fed females. Instead, the normally clustered LH surges were distributed widely with high inter-mouse variability in the light-fed group. These data indicate that mistimed feeding disrupts the temporal control of the neural processes underlying both ovulation and mating behavior, contributing to infertility.

Prenatal androgen treatment impairs the suprachiasmatic nucleus arginine-vasopressin to kisspeptin neuron circuit in female mice.

Polycystic ovary syndrome (PCOS) is associated with elevated androgen and luteinizing hormone (LH) secretion and with oligo/anovulation. Evidence indicates that elevated androgens impair sex steroid hormone feedback regulation of pulsatile LH secretion. Hyperandrogenemia in PCOS may also disrupt the preovulatory LH surge. The mechanisms through which this might occur, however, are not fully understood. Kisspeptin (KISS1) neurons of the rostral periventricular area of the third ventricle (RP3V) convey hormonal cues to gonadotropin-releasing hormone (GnRH) neurons. In rodents, the preovulatory surge is triggered by these hormonal cues and coincident timing signals from the central circadian clock in the suprachiasmatic nucleus (SCN). Timing signals are relayed to GnRH neurons, in part, via projections from SCN arginine-vasopressin (AVP) neurons to RP3VKISS1 neurons. Because rodent SCN cells express androgen receptors (AR), we hypothesized that these circuits are impaired by elevated androgens in a mouse model of PCOS. In prenatally androgen-treated (PNA) female mice, SCN Ar expression was significantly increased compared to that found in prenatally vehicle-treated mice. A similar trend was seen in the number of Avp-positive SCN cells expressing Ar. In the RP3V, the number of kisspeptin neurons was preserved. Anterograde tract-tracing, however, revealed reduced SCNAVP neuron projections to the RP3V and a significantly lower proportion of RP3VKISS1 neurons with close appositions from SCNAVP fibers. Functional assessments showed, on the other hand, that RP3VKISS1 neuron responses to AVP were maintained in PNA mice. These findings indicate that PNA changes some of the neural circuits that regulate the preovulatory surge. These impairments might contribute to ovulatory dysfunction in PNA mice modeling PCOS.

Outcomes of a GnRH Agonist Trigger Following a GnRH Antagonist or Flexible Progestin-Primed Ovarian Stimulation Cycle.

A suggested explanation for the pituitary-suppressive effects of progestin-primed ovarian stimulation cycles (PPOS) is pituitary luteinizing hormone (LH) depletion with progestin exposure during the follicular phase. The GnRH agonist (GnRHa) trigger releases endogenous LH from the pituitary, and if the LH depletion theory is correct, the response to the agonist trigger would be dampened in PPOS cycles. In this study, we compared the performance of the GnRHa trigger after PPOS and GnRH antagonist ovarian stimulation cycles. All women who underwent ovarian stimulation with the GnRH antagonist or flexible PPOS (fPPOS) and received a GnRH agonist trigger were eligible for inclusion. Outcomes included number of metaphase-II (MII) oocytes retrieved per cycle, rates of empty follicle syndrome, maturation, fertilization, blastulation, and cumulative clinical pregnancy per stimulation cycle. During the screening period, there were 166 antagonists and 58 fPPOS cycles triggered with a GnRH agonist. Groups were matched for potential confounders using propensity score matching. Progestin-downregulated cycles had 19% high mature oocyte yield (median: 14 vs. 19 MII oocytes, P = 0.03). Cumulative ongoing pregnancy or live birth rates were estimated after matching for transferred embryo count, and rates were similar between GnRH antagonist and fPPOS group (57.0% vs. 62.1%, P = 0.68). However, the number of remaining blastocysts was higher in the fPPOS group (median: 5.0 vs. 6.0, P < 0.001). LH levels were higher in fPPOS cycles compared to GnRH antagonist cycles up to the trigger day (P < 0.001). After the GnRHa trigger, fPPOS cycles were associated with a steeper LH surge compared with antagonist cycles (P = 0.02). Higher endogenous gonadotropin levels through the stimulation period and an LH surge of higher magnitude following a GnRHa trigger suggest a milder pituitary suppression by fPPOS, which needs to be confirmed in larger samples. It appears that progestins do not deplete pituitary LH reserves and a GnRHa trigger is usable after PPOS in women with high ovarian reserve.