Luteal phase support in assisted reproductive technology

Infertility affects one in six couples, with in vitro fertilization (IVF) offering many the chance of conception. Compared to the solitary oocyte produced during the natural menstrual cycle, the supraphysiological ovarian stimulation needed to produce multiple oocytes during IVF results in a dysfunctional luteal phase that can be insufficient to support implantation and maintain pregnancy. Consequently, hormonal supplementation with luteal phase support, principally exogenous progesterone, is used to optimize pregnancy rates; however, luteal phase support remains largely 'black-box' with insufficient clarity regarding the optimal timing, dosing, route and duration of treatment. Herein, we review the evidence on luteal phase support and highlight remaining uncertainties and future research directions. Specifically, we outline the physiological luteal phase, which is regulated by progesterone from the corpus luteum, and evaluate how it is altered by the supraphysiological ovarian stimulation used during IVF. Additionally, we describe the effects of the hormonal triggers used to mature oocytes on the degree of luteal phase support required. We explain the histological transformation of the endometrium during the luteal phase and evaluate markers of endometrial receptivity that attempt to identify the 'window of implantation'. We also cover progesterone receptor signalling, circulating progesterone levels associated with implantation, and the pharmacokinetics of available progesterone formulations to inform the design of luteal phase support regimens.

Beyond the Umbrella: A Systematic Review of the Interventions for the Prevention of and Reduction in the Incidence and Severity of Ovarian Hyperstimulation Syndrome in Patients Who Undergo In Vitro Fertilization Treatments

Ovarian hyperstimulation syndrome (OHSS) is the main severe complication of ovarian stimulation for in vitro fertilization (IVF) cycles. The aim of the current study was to identify the interventions for the prevention of and reduction in the incidence and severity of OHSS in patients who undergo IVF not included in systematic reviews with meta-analyses of randomized controlled trials (RCTs) and assess and grade their efficacy and evidence base. The best available evidence for each specific intervention was identified, analyzed in terms of safety/efficacy ratio and risk of bias, and graded using the Oxford Centre for Evidence-Based Medicine (CEBM) hierarchy of evidence. A total of 15 interventions to prevent OHSS were included in the final analysis. In the IVF population not at a high risk for OHSS, follitropin delta for ovarian stimulation may reduce the incidence of early OHSS and/or preventive interventions for early OHSS. In high-risk patients, inositol pretreatment, ovulation triggering with low doses of urinary hCG, and the luteal phase administration of a GnRH antagonist may reduce OHSS risk. In conclusion, even if not supported by systematic reviews with homogeneity of the RCTs, several treatments/strategies to reduce the incidence and severity of OHSS have been shown to be promising.

Luteal phase support for women trying to conceive by intrauterine insemination or sexual intercourse

BACKGROUND

Ovulation induction may impact endometrial receptivity due to insufficient progesterone secretion. Low progesterone is associated with poor pregnancy outcomes.

OBJECTIVES

To assess the effectiveness and safety of luteal phase support (LPS) in infertile women trying to conceive by intrauterine insemination or by sexual intercourse.

SEARCH METHODS

We searched the Cochrane Gynaecology and Fertility Group Specialised Register, CENTRAL, MEDLINE, Embase, PsycINFO, LILACS, trial registries for ongoing trials, and reference lists of articles (from inception to 25 August 2021).

SELECTION CRITERIA

Randomised controlled trials (RCTs) of LPS using progestogen, human chorionic gonadotropin (hCG), or gonadotropin-releasing hormone (GnRH) agonist supplementation in IUI or natural cycle.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Our primary outcomes were live birth rate/ongoing pregnancy rate (LBR/OPR) and miscarriage.  MAIN RESULTS: We included 25 RCTs (5111 participants). Most studies were at unclear or high risk of bias. We graded the certainty of evidence as very low to low. The main limitations of the evidence were poor reporting and imprecision. 1. Progesterone supplement versus placebo or no treatment  We are uncertain if vaginal progesterone increases LBR/OPR (risk ratio (RR) 1.10, 95% confidence interval (CI) 0.81 to 1.48; 7 RCTs; 1792 participants; low-certainty evidence) or decreases miscarriage per pregnancy compared to placebo or no treatment (RR 0.70, 95% CI 0.40 to 1.25; 5 RCTs; 261 participants). There were no data on LBR or miscarriage with oral stimulation. We are uncertain if progesterone increases LBR/OPR in women with gonadotropin stimulation (RR 1.24, 95% CI 0.80 to 1.92; 4 RCTs; 1054 participants; low-certainty evidence) and oral stimulation (clomiphene citrate or letrozole) (RR 0.97, 95% CI 0.58 to 1.64; 2 RCTs; 485 participants; low-certainty evidence). One study reported on OPR in women with gonadotropin plus oral stimulation; the evidence from this study was uncertain (RR 0.73, 95% CI 0.37 to 1.42; 1 RCT; 253 participants; low-certainty evidence). Given the low certainty of the evidence, it is unclear if progesterone reduces miscarriage per clinical pregnancy in any stimulation protocol (RR 0.68, 95% CI 0.24 to 1.91; 2 RCTs; 102 participants, with gonadotropin; RR 0.67, 95% CI 0.30 to 1.50; 2 RCTs; 123 participants, with gonadotropin plus oral stimulation; and RR 0.53, 95% CI 0.25 to 1.14; 2 RCTs; 119 participants, with oral stimulation). Low-certainty evidence suggests that progesterone in all types of ovarian stimulation may increase clinical pregnancy compared to placebo (RR 1.38, 95% CI 1.10 to 1.74; 7 RCTs; 1437 participants, with gonadotropin; RR 1.40, 95% CI 1.03 to 1.90; 4 RCTs; 733 participants, with gonadotropin plus oral stimulation (clomiphene citrate or letrozole); and RR 1.44, 95% CI 1.04 to 1.98; 6 RCTs; 1073 participants, with oral stimulation). 2. Progesterone supplementation regimen  We are uncertain if there is any difference between 300 mg and 600 mg of vaginal progesterone for OPR and multiple pregnancy (RR 1.58, 95% CI 0.81 to 3.09; 1 RCT; 200 participants; very low-certainty evidence; and RR 0.50, 95% CI 0.05 to 5.43; 1 RCT; 200 participants, very low-certainty evidence, respectively). No other outcomes were reported for this comparison. There were three different comparisons between progesterone regimens. For OPR, the evidence is very uncertain for intramuscular (IM) versus vaginal progesterone (RR 0.59, 95% CI 0.34 to 1.02; 1 RCT; 225 participants; very low-certainty evidence); we are uncertain if there is any difference between oral and vaginal progesterone (RR 1.25, 95% CI 0.70 to 2.22; 1 RCT; 150 participants; very low-certainty evidence) or between subcutaneous and vaginal progesterone (RR 1.05, 95% CI 0.54 to 2.05; 1 RCT; 246 participants; very low-certainty evidence). We are uncertain if IM or oral progesterone reduces miscarriage per clinical pregnancy compared to vaginal progesterone (RR 0.75, 95% CI 0.43 to 1.32; 1 RCT; 81 participants and RR 0.58, 95% CI 0.11 to 3.09; 1 RCT; 41 participants, respectively). Clinical pregnancy and multiple pregnancy were reported for all comparisons; the evidence for these outcomes was very uncertain. Only one RCT reported adverse effects. We are uncertain if IM route increases the risk of adverse effects when compared with the vaginal route (RR 9.25, 95% CI 2.21 to 38.78; 1 RCT; 225 participants; very low-certainty evidence). 3. GnRH agonist versus placebo or no treatment  No trials reported live birth. The evidence is very uncertain about the effect of GnRH agonist in ongoing pregnancy (RR 1.10, 95% CI 0.70 to 1.74; 1 RCT; 291 participants, very low-certainty evidence), miscarriage per clinical pregnancy (RR 0.73, 95% CI 0.26 to 2.10; 2 RCTs; 79 participants, very low-certainty evidence) and clinical pregnancy (RR 1.00, 95% CI 0.68 to 1.47; 2 RCTs; 340 participants; very low-certainty evidence), and multiple pregnancy (RR 0.28, 95% CI 0.11 to 0.70; 2 RCTs; 126 participants). 4. GnRH agonist versus vaginal progesterone  The evidence for the effect of GnRH agonist injection on clinical pregnancy is very uncertain (RR 1.00, 95% CI 0.51 to 1.95; 1 RCT; 242 participants). 5. HCG injection versus no treatment  The evidence for the effect of hCG injection on clinical pregnancy (RR 0.93, 95% CI 0.40 to 2.13; 1 RCT; 130 participants) and multiple pregnancy rates (RR 1.03, 95% CI 0.22 to 4.92; 1 RCT; 130 participants) is very uncertain. 6. Luteal support in natural cycle No study evaluated the effect of LPS in natural cycle. We could not perform sensitivity analyses, as there were no studies at low risk of selection bias and not at high risk in other domains.

AUTHORS' CONCLUSIONS

We are uncertain if vaginal progesterone supplementation during luteal phase is associated with a higher live birth/ongoing pregnancy rate. Vaginal progesterone may increase clinical pregnancy rate; however, its effect on miscarriage rate and multiple pregnancy rate is uncertain. We are uncertain if IM progesterone improves ongoing pregnancy rates or decreases miscarriage rate when compared to vaginal progesterone. Regarding the other reported comparisons, neither oral progesterone nor any other medication appears to be associated with an improvement in pregnancy outcomes (very low-certainty evidence).

Individualized luteal phase support after fresh embryo transfer: unanswered questions, a review

Background

Luteal phase support (LPS) is an important part of assisted reproductive technology (ART), and adequate LPS is crucial for embryo implantation. At present, a great number of studies have put emphasis on an individualized approach to controlled ovarian stimulation (COS) and endometrium preparation of frozen- thawed embryo transfer (FET); However, not much attention has been devoted to the luteal phase and almost all ART cycles used similar LPS protocol bases on experience.

Main body

This review aims to concisely summarize individualized LPS protocols in fresh embryo transfer cycles with hCG trigger or GnRH-a trigger. The PubMed and Google Scholar databases were searched using the keywords: (luteal phase support or LPS) AND (assisted reproductive technology or ART or in vitro fertilization or IVF). We performed comprehensive literature searches in the English language describing the luteal phase support after ART, since 1978 and ending in May 2019. Recent studies have shown that many modified LPS programs were used in ART cycle. In the cycle using hCG for final oocyte maturation, the progesterone with or without low dose of hCG may be adequate to maintain pregnancy. In the cycle using GnRH-a for trigger, individualized low dose of hCG administration with or without progesterone was suggested. The optimal timing to start the LPS would be between 24 and 72 h after oocyte retrieval and should last at least until the pregnancy test is positive. Addition of E₂ and the routes of progesterone administration bring no beneficial effect on the outcomes after ART.

Conclusions

Individualized LPS should be applied, according to the treatment protocol, the patients’ specific characteristics, and desires.

Luteal phase support (LPS) is an important part of assisted reproductive technology (ART). In the cycle using hCG for final oocyte maturation, the progesterone with or without low dose of hCG may be adequate to maintain pregnancy. In the cycle using GnRH-a for trigger, individualized low dose of hCG administration with or without progesterone was suggested. The optimal timing to start the LPS would be between 24 and 72 h after oocyte retrieval and should last at least until the pregnancy test is positive. Addition of E₂ and the routes of progesterone administration bring no beneficial effect on the outcomes after ART. Individualized LPS should be applied, according to the treatment protocol, the patients’ specific characteristics, and desires.

Luteal-phase support in assisted reproductive technology: An ongoing challenge

It has been shown that in controlled ovarian hyper stimulation cycles, defective luteal phase is common. There are many protocols for improving pregnancy outcomes in women undergoing fresh and frozen in vitro fertilization cycles. These approaches include progesterone supplements, human chorionic gonadotropin, estradiol, gonadotropin-releasing hormone agonist, and recombinant luteinizing hormone. The main challenge is luteal-phase support (LPS) in cycles with gonadotropin-releasing hormone agonist triggering. There is still controversy about the optimal component and time for starting LPS in assisted reproductive technology cycles. This review aims to summarize the various protocols suggested for LPS in in vitro fertilization cycles.

Time, time, time: see what governs the luteal phase endocrinology

Two modes of ovulation trigger are used in IVF: hCG, acting on ovarian LH receptors, and GnRH agonist, eliciting pituitary LH and FSH surges. These two modes are evaluated herein, focusing on how they serve specific time-sensitive events crucial for achieving embryo implantation and pregnancy. hCG trigger is associated with significant timing deviation from physiology. Peak progesterone is not synchronized with implantation window; progesterone level does not rise continuously to a mid-luteal peak, but rather drops from a too early peak. The luteal phase endocrinology post GnRH agonist trigger is characterized by a quick and irreversible luteolysis. Therefore, freeze all strategy is advised, if there is a risk of ovarian hyperstimulation syndrome. If fresh transfer is desired, numerous approaches for luteal phase support have been suggested. However, a thorough understanding of time-sensitive events suggests that a single 1,500 IU hCG dose, administered 48 h post oocyte retrieval, is all that is needed to fully support the luteal phase and secure best chances of achieving pregnancy.

A Randomized Controlled Trial on the Efficacy and Safety of Low-Dose hCG in a Short Protocol with GnRH Agonist and Ovarian Stimulation with Recombinant FSH (rFSH) During the Follicular Phase in Infertile Women Undergoing ART

Τhis study aims to investigate whether the addition of low-dose hCG throughout stimulation in infertile women undergoing IVF improves IVF outcome parameters. This is a prospective, multicenter, randomized, double-blind, placebo-controlled, Phase IIIb clinical study, conducted in three university IVF units. We studied whether the addition of 100 IU hCG/day to a short GnRH agonist IVF protocol from the onset of the follicular phase (group 1, n=40) or placebo (group 2, n=41) had any impact on the number of high-quality transferred embryos at day 2 and clinical pregnancy rates. The comparison encompassed descriptive statistics, and univariate and multivariate analyses. Concerning the primary outcomes, we found no differences in both the number of high-quality embryos (≥2) at day 3 [21/40 (52.5%) vs. 14/41 (34.2%), p=0.095] and clinical pregnancy rates [10/40 (25%) vs. 10/41 (24.4%), p=0.949], respectively. Similarly, there were no differences concerning the secondary outcomes preset for this trial. According to the results of the multivariate logistic regression analysis, no significant associations were noted for primary outcomes (clinical pregnancy: adjusted OR=0.89, 95% CI: 0.29–2.75; (≥2 excellent quality embryos at day 3: adjusted OR=0.54, 95% CI: 0.21–1.42, with group 1 set as reference category); similarly, no differences were noted with respect to secondary outcomes, except from the increased odds of ≥2 poor-quality embryos at day 3 occurring in group 2 (adjusted OR= 11.69, 95%CI: 1.29–106.19). The addition of low-dose hCG to a short GnRH agonist protocol for IVF does not improve the number of top-quality embryos and clinical pregnancy rates.

IVF and the exogenous progesterone-free luteal phase

PURPOSE OF REVIEW

In a conventional IVF cycle, final oocyte maturation and ovulation is triggered with a bolus of hCG, followed by progesterone-based luteal support that spans several weeks if pregnancy is achieved. This article summarizes several approaches of the exogenous progesterone-free luteal support in IVF.

RECENT FINDINGS

Triggering ovulation with GnRH agonist may serve as an alternative to hCG, with well established advantages. In addition, the luteal phase can be individualized in order to achieve a more physiologic hormonal milieu, and a more patient friendly treatment, alleviating the burden of a lengthy exogenous progesterone therapy.

SUMMARY

GnRH agonist trigger followed by a 'freeze all' policy is undoubtedly the best approach towards the 'OHSS-free clinic'. If fresh embryo transfer is considered well tolerated after GnRH agonist trigger, rescue of the corpora lutea by LH activity supplementation is mandatory. Herein we discuss the different approaches of corpus luteum rescue.

The exogenous progesterone-free luteal phase: two pilot randomized controlled trials in IVF patients

RESEARCH QUESTION

Is the reproductive outcome similar after gonadotrophin-releasing hormone agonist (GnRHa) trigger followed by luteal human chorionic gonadotrophin (HCG) boluses compared with HCG trigger and a standard luteal phase support (LPS)?

DESIGN

Two open-label pilot randomized controlled trials (RCT) with 250 patients from 2014 to 2019, with a primary outcome of ongoing pregnancy per embryo transfer. Patients with ≤13 follicles on the trigger day were randomized (RCT 1) to: Group A (n = 65): GnRHa trigger followed by a bolus of 1500 IU HCG s.c. on the oocyte retrieval day (ORD) and 1000 IU HCG s.c. 4 days later, and no vaginal LPS; or Group B (n = 65): 6500 IU HCG trigger, followed by a standard vaginal progesterone LPS. Patients with 14-25 follicles on the trigger day were randomized (RCT 2) to Group C (n = 60): GnRHa trigger followed by 1000 IU HCG s.c. on ORD and 500 IU HCG s.c. 4 days later, and no vaginal LPS; or Group D (n = 60): 6500 IU HCG trigger and a standard vaginal LPS.

RESULTS

In RCT 1, the ongoing pregnancy rate was 44% (22/50) in the GnRHa group versus 46% (25/54) in the HCG trigger group (RR 0.95, 95% CI 0.62-1.45). No ovarian hyperstimulation syndrome (OHSS) was seen in Groups A or B. In RCT 2, the ongoing pregnancy rate was 51% (25/49) in the GnRHa group versus 60% (31/52) in the HCG trigger group (RR 0.86, 95% CI 0.60-1.22). The OHSS rates were 3.3% and 6.7%, respectively.

CONCLUSIONS

Although a larger-scale study is needed before standard clinical implementation, the present study supports that the exogenous progesterone-free LPS is efficacious, simple and patient-friendly.

Luteal Support with very Low Daily Dose of Human Chorionic Gonadotropin after Fresh Embryo Transfer as an Alternative to Cycle Segmentation for High Responders Patients Undergoing Gonadotropin-Releasing Hormone Agonist-Triggered IVF

The segmentation of the in vitro fertilization (IVF) cycle, consisting of the freezing of all embryos and the postponement of embryo transfer (ET), has become popular in recent years, with the main purpose of preventing ovarian hyperstimulation syndrome (OHSS) in patients with high response to controlled ovarian stimulation (COS). Indeed cycle segmentation (CS), especially when coupled to a GnRH-agonist trigger, was shown to reduce the incidence of OHSS in high-risk patients. However, CS increases the economic costs and the work amount for IVF laboratories. An alternative strategy is to perform a fresh ET in association with intensive luteal phase pharmacological support, able to overcome the negative effects of the GnRH-agonist trigger on the luteal phase and on endometrial receptivity. In order to compare these two strategies, we performed a retrospective, real-life cohort study including 240 non-polycystic ovarian syndrome (PCO) women with expected high responsiveness to COS (AMH >2.5 ng/mL), who received either fresh ET plus 100 IU daily human chorionic gonadotropin (hCG) as luteal support (FRESH group, n = 133), or cycle segmentation with freezing of all embryos and postponed ET (CS group, n = 107). The primary outcomes were: implantation rate (IR), live birth rate (LBR) after the first ET, and incidence of OHSS. Overall, significantly higher IR and LBR were observed in the CS group than in the FRESH group (42.9% vs. 27.8%, p < 0.05 and 32.7% vs. 19.5%, p < 0.05, respectively); the superiority of CS strategy was particularly evident when 16-19 oocytes were retrieved (LBR 42.2% vs. 9.5%, p = 0.01). Mild OHSS appeared with the same incidence in the two groups, whereas moderate and severe OHSS forms were observed only in the FRESH group (1.5% and 0.8%, respectively). In conclusion, in non-PCO women, high responders submitted to COS with the GnRH-antagonist protocol and GnRH-agonist trigger, CS strategy was associated with higher IR and LBR than the strategy including fresh ET followed by luteal phase support with a low daily hCG dose. CS appears to be advisable, especially when >15 oocytes are retrieved.

Angiogenic cytokine and interleukin 8 levels in early luteal phase after triggering ovulation with gonadotropin-releasing hormone agonist in high-responder patients

PROBLEM

Interleukin 8 (IL-8), vascular endothelial growth factor A (VEGFA), its receptors 1 (VEGFR1) and 2 (VEGFR2) are associated with ovarian hyperstimulation syndrome (OHSS) pathophysiological mechanisms. The aim of this study was to evaluate the concentrations of these cytokines depending on the way of ovulation triggering.

METHOD OF STUDY

A total of 51 high-responder patients underwent IVF program and received gonadotropin-releasing hormone agonists (GnRHa) trigger + 1500 IU human chorionic gonadotropin (hCG) support on the oocyte pick-up (OPU) day (group I), dual trigger (GnRHa + 1500 IU hCG; group II), or hCG trigger 10,000 IU (group III) for the final oocyte maturation. The concentrations of cytokines were evaluated in serum by the enzyme-linked immunosorbent assay kit.

RESULT(S)

VEGFR2 levels were significantly lower in groups I and II than in group III in serum on the OPU (I vs. III, p = .0456; II vs. III, p = .0122) and OPU + 5 day (I vs. III, p = .0004; II vs. III, p = .0082). VEGFA levels were lower in group I than in group III (p = .0298) on the OPU day, however, were similar in all groups on the OPU + 5 day.

CONCLUSION(S)

A small dose of hCG elicits similar concentrations of VEGFA to a full dose of hCG; however, GnRHa triggering reduces the concentrations of VEGFR2, which could lead to the OHSS prevention.

Dual trigger in normally-responding assisted reproductive technology patients increases the number of top-quality embryos

Objective

The feasibility of a gonadotropin-releasing hormone agonist (GnRHa) trigger in normal responders is still a matter of debate. The aim of this study was to compare the number of mature oocytes, the number of good-quality embryos, and the live birth rate in normal responders triggered by GnRHa alone, GnRHa and human chorionic gonadotropin (hCG; a dual trigger), and hCG alone.

Methods

A retrospective cohort study was conducted at the infertility clinic of a university hospital. Data from 200 normal responders who underwent controlled ovarian hyperstimulation and intracytoplasmic sperm injection with a GnRH antagonist protocol between January 2016 and January 2017 were reviewed. The first study group consisted of patients with cycles triggered by GnRHa alone. The second study group consisted of patients with cycles triggered by both GnRHa and low-dose hCG (a dual trigger). The control group consisted of patients with cycles triggered by hCG alone.

Results

The groups were comparable in terms of demographics and cycle characteristics. The numbers of total oocytes retrieved and metaphase II oocytes were similar between the groups. The total numbers of top-quality embryos were 3.2±2.9 in the GnRHa group, 4.4±3.2 in the dual-trigger group, and 2.9±2.1 in the hCG group (p=0.014). The live birth rates were 21.4%, 30.5%, and 28.2% in those groups, respectively (p=0.126).

Conclusion

In normal responders, a dual-trigger approach appears superior to an hCG trigger alone with regard to the number of top-quality embryos produced. However, no clinical benefit was apparent in terms of live birth rates.

GnRH agonist triggering followed by 1500 IU of HCG 48 h after oocyte retrieval for luteal phase support

RESEARCH QUESTION

Gonadotrophin releasing hormone (GnRH) agonist trigger after GnRH antagonist-based ovarian stimulation protocol for IVF is gaining popularity, because it prevents ovarian hyperstimulation syndrome and allows for near physiological LH and FSH surges. A small dose of HCG (1500 IU) on the day of oocyte retrieval, followed by daily progesterone administration, is currently the preferred way to secure adequate luteal support after GnRH agonist trigger. In the present study, the possibility that a bolus of 1500 IU HCG, given 2 days after oocyte retrieval, may be sufficient to sustain adequate luteal support without additional progesterone treatment was questioned.

DESIGN

A non-interventional retrospective cohort study between conducted between April 2017 and August 2018. A total of 154 consecutive patients treated with GnRH agonist trigger followed by day-2 HCG (1500 IU) support only (study group) were included. Data were compared with 155 consecutive patients who were treated with HCG (6500 IU) trigger followed by conventional progesterone luteal support (control group).

RESULTS

Pregnancy, miscarriage and live birth rates were comparable between the study and control groups. In patients who became pregnant, mean oestradiol level 14 days after oocyte retrieval was 4719 pmol/l and 2672 pmol/l in the study and control group, respectively (P < 0.001), reflecting robust luteal activity in the study group.

CONCLUSIONS

A bolus of 1500 IU HCG, administered 2 days after retrieval, can provide excellent luteal support, without the need for further progesterone supplementation.

Shortcomings of an unphysiological triggering of oocyte maturation using human chorionic gonadotropin

Final maturation of follicles has, in connection with ovarian stimulation and infertility treatment, traditionally been achieved by the administration of a human chorionic gonadotropin (hCG) bolus trigger of 5,000 to 10,000 IU. This trigger serves two purposes: induce oocyte maturation; and serve as luteal phase support owing to its long half-life. It now appears that the hCG bolus trigger is unable to support both these two purposes optimally. In particular, after an hCG trigger, the early luteal phase is hormonally abnormal and different from conditions observed in the natural menstrual cycle: the timing of the initiation of hCG and progesterone rise is much faster after an hCG trigger than in a natural menstrual cycle; the maximal concentrations of hCG and progesterone considerably exceed those naturally observed; and the timing of the peak progesterone concentration after an hCG trigger is advanced several days compared with the natural cycle. Furthermore, the hCG trigger without any follicle-stimulating hormone activity may induce oocyte maturation less efficiently than the combined luteinizing hormone and follicle-stimulating hormone surge normally seen. Collectively, the endometrium is likely to be advanced after an hCG trigger, and the implantation potential is probably not optimal. The precise effect on pregnancy rates after the different progressions of hCG and progesterone concentrations during the early luteal phase has not yet been determined, but more individualized methods using more physiological approaches are likely to improve reproductive outcomes.

Gonadotropin-releasing hormone agonist for ovulation trigger - OHSS prevention and use of modified luteal phase support for fresh embryo transfer

The introduction of gonadotrophin-releasing hormone agonist (GnRHa) trigger greatly impacted modern IVF treatment. Patients at low risk of ovarian hyperstimulation syndrome (OHSS) development, undergoing fresh embryo transfer and GnRHa trigger can be offered a virtually OHSS-free treatment with non-inferior reproductive outcomes by using a modified luteal phase support in terms of small boluses of human chorionic gonadotrophin (hCG), daily recombinant luteinizing hormone LH (rLH) or GnRHa. In the OHSS risk patient, GnRHa trigger can safely be performed, followed by a 'freeze-all' policy with a minimal risk of OHSS development and high live birth rates in the subsequent frozen embryo transfer cycle. Importantly, GnRHa trigger opened the 'black box' of the luteal phase, promoting research in the most optimal steroid levels during the luteal phase. GnRHa trigger allows high-dose gonadotropin stimulation to achieve the optimal number of oocytes and embryos needed to ensure the highest chance of live birth. This review thoroughly discusses how the GnRHa trigger concept adds safety and efficacy to modern IVF in terms of OHSS prevention. Furthermore, the optimal luteal phase management after GnRHa trigger in fresh embryo transfer cycles is discussed.

The impact of adding hp-hMG in r-FSH started GnRH antagonist cycles on ART outcome

While luteinizing hormone (LH) activity is believed to play a role in follicle maturation, human chorionic gonadotropin (hCG) might play an important role in implantation process. We aimed to investigate whether addition of human menopausal gonadotropin (hMG) in recombinant-follicle-stimulating hormone (r-FSH) started GnRH antagonist controlled ovarian hyperstimulation (COH) cycles might enhance implantation rate and improve in vitro fertilization (IVF) success. A total of 246 patients undergoing GnRH antagonist IVF cycles were analyzed. One hundred and twenty-three cycles (%50) were treated with only r-FSH and 123 cycles were treated with r-FSH plus hp-hMG combination. Total gonadotropin doses, total number of oocytes retrieved, metaphase 2 (MII) oocytes, top quality embryos, fertilization and implantation rates, clinical pregnancy rates (CPRs) and ovarian hyperstimulation syndrome (OHSS) rates were compared between the groups. Both groups were comparable in terms of demographic details and baseline characteristics. Peak estradiol and progesterone levels in hCG trigger day, number of retrieved oocytes and top quality embryo counts, fertilization rates were similar between the groups. In r-FSH + hp-hMG group, significantly higher implantation rates (35.3% vs 24.3%, p=.017), CPRs (51.2% vs 35.8%, p=.015) and lower OHSS rates (1.6% vs 7.4%, p = .03) were observed respectively compared to r-FSH only treated patients. In conclusion, addition of hp-hMG on the day of antagonist initiation might increase CPRs. A better endometrial receptivity associated with higher implantation rates might be achieved due to hCG component in hp-hMG.

Luteal phase support with GnRH agonist does not eliminate the risk for ovarian hyperstimulation syndrome

This study aims to report a case of early, severe ovarian hyperstimulation syndrome (OHSS) following GnRH agonist trigger for final oocyte maturation despite luteal support with a GnRH agonist. Contrary to the claim that luteal support using a GnRH agonist eliminates the risk for OHSS in high-risk patients, this report alerts practitioners to the risk of severe OHSS development despite GnRH agonist luteal support in patients receiving GnRH antagonist protocol with GnRH agonist triggering and cautions the practitioners to consider other measures of OHSS prevention.

The impact of HCG in IVF Treatment: Does it depend on age or on protocol?

OBJECTIVE

to evaluate the effect of the addition of low dose human chorionic gonadotropin (hCG) to human menopausal gonadotropin (HMG) throughout the early follicular phase in controlled ovarian stimulation (COS) conducted with two difference regimens. Gonadotropin-releasing hormone (GnRH) antagonist and short GnRH-agonist protocol were applied in two in vitro fertilization (IVF) clinics.

METHODS

Clinical study conducted during the period 2014-2016 in two IVF clinics in a cohort of 240 women. In the first group 1 (124 women), a GnRH antagonist protocol with HMG and addition of low dose (100IU/day) h CG was applied. The other group 2 consisted of 116 women who underwent a short GnRH- agonist protocol with HMG and addition of low dose (100IU/day) h CG.

RESULTS

Multiple logistic regression analysis was performed. The group 2 found to be associated with greater number of follicles and oocytes. The pregnancy rates were 12.1% and 26.7% in group 1 and group 2, respectively (p=0.004). For patients over 40 years, the number of follicles and oocytes retrieved were significant higher in group 2.The pregnancy rate in group 2 was higher than in group 1 (21, 6% vs 5%, p=0.017).

CONCLUSIONS

Advanced age women are likely to achievepregnancy using the GnRH Short than GnRH antagonist, when HMG/hCG is used, while HMG-hCG gonadotropins have the same potentialas Recombinant follicle stimulating hormone (rFSH)-hCG used in GnRH short protocol.

Novel Concepts for Inducing Final Oocyte Maturation in In Vitro Fertilization Treatment

Infertility affects one in six of the population and increasingly couples require treatment with assisted reproductive techniques. In vitro fertilization (IVF) treatment is most commonly conducted using exogenous FSH to induce follicular growth and human chorionic gonadotropin (hCG) to induce final oocyte maturation. However, hCG may cause the potentially life-threatening iatrogenic complication "ovarian hyperstimulation syndrome" (OHSS), which can cause considerable morbidity and, rarely, even mortality in otherwise healthy women. The use of GnRH agonists (GnRHas) has been pioneered during the last two decades to provide a safer option to induce final oocyte maturation. More recently, the neuropeptide kisspeptin, a hypothalamic regulator of GnRH release, has been investigated as a novel inductor of oocyte maturation. The hormonal stimulus used to induce oocyte maturation has a major impact on the success (retrieval of oocytes and chance of implantation) and safety (risk of OHSS) of IVF treatment. This review aims to appraise experimental and clinical data of hormonal approaches used to induce final oocyte maturation by hCG, GnRHa, both GnRHa and hCG administered in combination, recombinant LH, or kisspeptin. We also examine evidence for the timing of administration of the inductor of final oocyte maturation in relationship to parameters of follicular growth and the subsequent interval to oocyte retrieval. In summary, we review data on the efficacy and safety of the major hormonal approaches used to induce final oocyte maturation in clinical practice, as well as some novel approaches that may offer fresh alternatives in future.

Day two post retrieval 1500 IUI hCG bolus, progesterone-free luteal support post GnRH agonist trigger - a proof of concept study

Small dose of hCG (1500 IU) on the day of oocyte retrieval, followed by daily progesterone administration, is currently the preferred way to secure adequate luteal support following GnRH agonist trigger. In the current proof-of-concept study, we explored the possibility that a bolus of 1500 IU hCG, given two days after oocyte retrieval, may be sufficient to sustain adequate luteal support without additional progesterone treatment. From February 2015 to August 2016, we obtained 44 pregnancies following GnRHa trigger followed by day 2 hCG (1500 IU) support only (study group). Data from these 44 cycles were compared with the latest 44 pregnancies obtained following hCG (6500 IU) trigger followed by conventional progesterone luteal documented (control group). Mean progesterone levels (14 days postoocyte retrieval) in the study and control groups were 197 nmol/l and 173 nmol/l, respectively (NS). Mean E₂ levels (14 days post oocyte retrieval) in the study group was 6937 pmol/l, significantly higher (p < .001) than in the control group (3.276 pmol/l). We conclude that bolus of 1500 IU hCG, administered 2 days after retrieval, can provide excellent support, without the need to further supplement with progesterone.

Luteal Coasting and Individualization of Human Chorionic Gonadotropin Dose after Gonadotropin-Releasing Hormone Agonist Triggering for Final Oocyte Maturation-A Retrospective Proof-of-Concept Study

Ovarian stimulation in a gonadotropin-releasing hormone (GnRH) antagonist protocol with the use of GnRH agonist for final oocyte maturation is the state-of-the-art treatment in patients with an expected or known high response to avoid or at least reduce significantly the risk for development of ovarian hyperstimulation syndrome (OHSS). Due to a shortened LH surge after administration of GnRH agonist in most patients, the luteal phase will be characterized by luteolysis and luteal phase insufficiency. Maintaining a sufficient luteal phase is crucial for achievement of a pregnancy; however, the optimal approach is still under debate. Administration of human chorionic gonadotropin (hCG) within 72 h rescues the corpora lutea function; however, the so far often used 1,500 IU still bear the risk for development of OHSS. The recently introduced concept of "luteal coasting" individualizes the luteal phase support by monitoring the progesterone concentrations and administering a rescue dosage of hCG when progesterone concentrations drop significantly. This retrospective proof-of-concept study explored the correlation between hCG dosages ranging from 375 up to 1,500 IU and the progesterone levels in the early and mid-luteal phases as well as the likelihood of pregnancy, both early and ongoing. The chance of pregnancy is highest with progesterone level ≥13 ng/ml at 48 h postoocyte retrieval. Among the small sample size of 52 women studied, it appears that appropriate progesterone levels can be achieved with hCG dosages as low as 375 IU. This may well optimize the chance of pregnancy while reducing the risk of OHSS associated with higher doses of hCG supplementation in the luteal phase.

Functional Characterization of MicroRNA-27a-3p Expression in Human Polycystic Ovary Syndrome

The goal of this study was to characterize the function of microRNA-27a-3p (miR-27a-3p) in polycystic ovary syndrome (PCOS). miR-27a-3p expression was analyzed in excised granulosa cells (GCs) from 21 patients with PCOS and 12 normal patients undergoing in vitro fertilization cycle treatments and in 17 nontreated cuneiform ovarian resection PCOS samples and 13 control ovarian samples from patients without PCOS. We found that the expression of miR-27a-3p was significantly increased in both excised GCs and the ovaries of patients with PCOS compared with the controls. Insulin treatment of the human granulosa-like tumor cell line (KGN) resulted in decreased downregulated expression of miR-27a-3p, and this effect appeared to be mediated by signal transducer and activator of transcription STAT1 and STAT3. The overexpression of miR-27a-3p in KGN cells inhibited SMAD5, which in turn decreased cell proliferation and promoted cell apoptosis. After KGN cells were stimulated with insulin for 48 hours, there was increased expression of SMAD5 protein and decreased apoptosis. Additionally, knockdown/overexpression of SMAD5 in KGN cells reduced/increased cell number and promoted/inhibited cell apoptosis. Insulin-stimulated primary GCs isolated from patients with PCOS, in contrast to normal GCs or KGN cells, did not exhibit decreased miR-27a-3p expression. The differences in the expression levels in KGN cells and human PCOS GCs are likely explained by increased miR-27a-3p expression in the GCs caused by insulin resistance in PCOS. Taken together, our data provided evidence for a functional role of miR-27a-3p in the GCs' dysfunction that occurs in patients with PCOS.

Individual luteolysis pattern after GnRH-agonist trigger for final oocyte maturation

Final oocyte maturation using GnRH-agonist trigger in a GnRH-antagonist protocol is increasingly common, as ovarian hyperstimulation syndrome is almost completely avoided. However, this approach might lead to reduced pregnancy rates due to severe luteolysis. This proof of concept study evaluated the extend of luteolysis by measuring progesterone levels 48 hours after oocyte retrieval in 51 patients, who received GnRH-agonist trigger for final oocyte maturation in a GnRH-antagonist protocol due to the risk of ovarian hyperstimulation syndrome. It was shown, that luteolysis after GnRHa-trigger differs greatly among patients, with progesterone levels ranging from 13.0 ng/ml to ≥ 60.0 ng/ml, 48 hours after oocyte retrieval. Significant positive correlations could be demonstrated between progesterone levels and the number of ovarian stimulation and suppression days (p = 0.006 and p = 0.002 respectively), the total amount of medication used for ovarian suppression (p = 0.015), the level of progesterone on the day of final oocyte maturation (p = 0.008) and the number of retrieved oocytes (p = 0.019). Therefore it was concluded, that luteolysis after GnRH-agonist trigger is patient-specific and also luteal phase support requires individualization. Longer stimulation duration as well as a higher level of progesterone on the day of final oocyte maturation and more retrieved oocytes will result in higher levels of progesterone 48 hours after oocyte retrieval.

Individual luteolysis post GnRH-agonist-trigger in GnRH-antagonist protocols

Over the past few years, the use of Gonadotropin-releasing-hormone (GnRH)-agonist for final oocyte maturation in GnRH-antagonist-protocols in stimulated IVF/ICSI cycles has gained worldwide acceptance, as this approach reduces significantly the risk for development of ovarian hyperstimulation syndrome (OHSS). Final oocyte maturation with GnRH-agonist leads to sever luteolysis, which cannot be counterbalanced using standard luteal phase support with purely progesterone (P4) application and therefore administration of hCG or high doses of P4 is considered to be essential to prevent/counteract luteolysis. However, lately publications indicate, that luteolysis is not always complete after GnRH-agonist for trigger. This case-series evaluates the degree of luteolysis in high-responder-patients, who received GnRH-agonist for final oocyte maturation. Assessment of estradiol (E2)- and P4-levels 48 h after oocyte-pick-up (OPU) procedure demonstrate clearly, that luteolysis after GnRH-agonist trigger is individual-specific, even in high-responder patients with the same number of oocytes. Hence, individualization of luteal phase support with the focus on avoiding unnecessary administration of hCG, bearing the risk for development of OHSS, a new concept of luteal coasting needs to be developed, based on severity of luteolysis following luteal coasting.

GnRH Agonist Trigger and LH Activity Luteal Phase Support versus hCG Trigger and Conventional Luteal Phase Support in Fresh Embryo Transfer IVF/ICSI Cycles-A Systematic PRISMA Review and Meta-analysis

INTRODUCTION

The use of GnRH agonist (GnRHa) for final oocyte maturation trigger in oocyte donation and elective frozen embryo transfer cycles is well established due to lower ovarian hyperstimulation syndrome (OHSS) rates as compared to hCG trigger. A recent Cochrane meta-analysis concluded that GnRHa trigger was associated with reduced live birth rates (LBRs) in fresh autologous IVF cycles compared to hCG trigger. However, the evidence is not unequivocal, and recent trials have found encouraging reproductive outcomes among couples undergoing GnRHa trigger and individualized luteal LH activity support. Thus, the aim was to compare GnRHa trigger followed by luteal LH activity support with hCG trigger in IVF patients undergoing fresh embryo transfer.

MATERIAL AND METHODS

We conducted a systematic review and meta-analysis of randomized trials published until December 14, 2016. The population was infertile patients submitted to IVF/ICSI cycles with GnRH antagonist cotreatment who underwent fresh embryo transfer. The intervention was GnRHa trigger followed by LH activity luteal phase support (LPS). The comparator was hCG trigger followed by a standard LPS. The critical outcome measures were LBR and OHSS rate. The secondary outcome measures were number of oocytes retrieved, clinical and ongoing pregnancy rates, and miscarriage rates.

RESULTS

A total of five studies met the selection criteria comprising a total of 859 patients. The LBR was not significantly different between the GnRHa and hCG trigger groups (OR 0.84, 95% CI 0.62, 1.14). OHSS was reported in a total of 4/413 cases in the GnRHa group compared to 7/413 in the hCG group (OR 0.48, 95% CI 0.15, 1.60). We observed a slight, but non-significant increase in miscarriage rate in the GnRHa triggered group compared to the hCG group (OR 1.85; 95% CI 0.97, 3.54).

CONCLUSION

GnRHa trigger with LH activity LPS resulted in comparable LBRs compared to hCG trigger. The most recent trials reported LBRs close to unity indicating that individualization of the LH activity LPS improved the luteal phase deficiency reported in the first GnRHa trigger studies. However, LPS optimization is needed to further limit OHSS in the subgroup of normoresponder patients (<14 follicles ≥ 11 mm).

PROSPERO REGISTRATION NUMBER

CRD42016051091.

Micro-dose hCG as luteal phase support without exogenous progesterone administration: mathematical modelling of the hCG concentration in circulation and initial clinical experience

For the last two decades, exogenous progesterone administration has been used as luteal phase support (LPS) in connection with controlled ovarian stimulation combined with use of the human chorionic gonadotropin (hCG) trigger for the final maturation of follicles. The introduction of the GnRHa trigger to induce ovulation showed that exogenous progesterone administration without hCG supplementation was insufficient to obtain satisfactory pregnancy rates. This has prompted development of alternative strategies for LPS. Augmenting the local endogenous production of progesterone by the multiple corpora lutea has been one focus with emphasis on one hand to avoid development of ovarian hyper-stimulation syndrome and, on the other hand, to provide adequate levels of progesterone to sustain implantation. The present study evaluates the use of micro-dose hCG for LPS support and examines the potential advances and disadvantages. Based on the pharmacokinetic characteristics of hCG, the mathematical modelling of the concentration profiles of hCG during the luteal phase has been evaluated in connection with several different approaches for hCG administration as LPS. It is suggested that the currently employed LPS provided in connection with the GnRHa trigger (i.e. 1.500 IU) is too strong, and that daily micro-dose hCG administration is likely to provide an optimised LPS with the current available drugs. Initial clinical results with the micro-dose hCG approach are presented.