Individualized versus conventional ovarian stimulation for in vitro fertilization: a multicenter, randomized, controlled, assessor-blinded, phase 3 noninferiority trial

Living in a low socioeconomic status neighbourhood is associated with lower cumulative ongoing pregnancy rate after IVF treatment

RESEARCH QUESTION

Does an association exist between neighbourhood socioeconomic status (SES) and the cumulative rate of ongoing pregnancies after 2.5 years of IVF treatment?

DESIGN

A retrospective observational study involving 2669 couples who underwent IVF or IVF and intracytoplasmic sperm injection treatment between 2006 and 2020. Neighbourhood SES for each couple was determined based on their residential postal code. Subsequently, SES was categorized into low (p80). Multivariable binary logistic regression analyses were conducted, with the cumulative ongoing pregnancy within 2.5 years as the outcome variable. The SES category (reference category: high), female age (reference category: 32-36 years), body mass index (reference category: 23-25 kg/m2), smoking status (yes/no), number of oocytes after the first ovarian stimulation, embryos usable for transfer or cryopreservation after the first cycle, duration of subfertility before treatment and insemination type were used as covariates.

RESULTS

A variation in ongoing pregnancy rates was observed among SES groups after the first fresh embryo transfer. No difference was found in the median number of IVF treatment cycles carried out. The cumulative ongoing pregnancy rates differed significantly between SES groups (low: 44%; medium: 51%; high: 56%; P < 0.001). Low neighbourhood SES was associated with significantly lower odds for achieving an ongoing pregnancy within 2.5 years (OR 0.66, 95% CI 0.52 to 0.84, P < 0.001).

CONCLUSION

Low neighbourhood SES compared with high neighbourhood SES is associated with reducing odds of achieving an ongoing pregnancy within 2.5 years of IVF treatment.

The pregnancy outcomes among women receiving individualized algorithm dosing with follitropin delta: a systematic review of randomized controlled trials

PURPOSE

To investigate whether the ovarian stimulation with follitropin delta in an individualized algorithm-based manner is inferior to recombinant human-follicle stimulating's follitropin alfa or follitropin beta conventional dosing regarding a series of established primary endpoints.

METHODS

We conducted a registered systematic review (CRD42024512792) on PubMed-MEDLINE, Web of Science™, Cochrane Database of Systematic Reviews, and Scopus. Our search was designed to cover all relevant literature, particularly randomized controlled trials. We critically and comparatively analyzed the outcomes for each primary endpoint based on the intervention, reflected by the positive βhCG test, clinical pregnancy, vital pregnancy, ongoing pregnancy, live birth, live birth at 4 weeks, and multiple pregnancies.

RESULTS

Six randomized controlled trials were included in the quality assessment as priority manuscripts, revealing an 83.3% low risk of bias. Follitropin delta led to non-significant differences in each parameter of interest from positive βhCG test (691; 53.44% vs. 602; 46.55%), ongoing pregnancies (603; 53.79% vs. 518; 46.20%), clinical and vital pregnancies (1,073; 52.80% vs. 959; 47.19%), to live birth and at 4 weeks (595; 54.14% vs. 504; 45.85%) with only 2 losses, and even multiple pregnancies (8; 66.66% vs. 4; 33.33%). However, follitropin delta was well-tolerated among hypo- and hyper-responders without significant risk of ovarian hyperstimulation syndrome and/or preventive interventions in contrast with follitropin alfa or follitropin beta.

CONCLUSION

The personalized individualized-based algorithm dosing with follitropin delta is non-inferior to conventional follitropin alfa or follitropin beta. It is as effective in promoting a similar response in women without significant comparable adverse effects.

Comparison of stimulation protocols for dose determination of gonadotropins: A systematic review and Bayesian network meta-analysis based on randomized controlled trials

BACKGROUND

To date, evidence regarding the effectiveness and safety of individualized controlled ovarian stimulation (COS) compared with standard dose COS has been inadequate.

OBJECTIVES

To evaluate the updated evidence from published randomized controlled trials (RCTs) about the efficacy and safety of individualized COS with different ovarian reserve test biomarkers or clinical experience versus standard dose COS.

SEARCH STRATEGY

Terms and descriptors related to COS, individualized or standard, and RCT were combined to search, and only English language studies were included. Conference abstracts and comments were excluded.

SELECTION CRITERIA

RCTs with comparison between different individualized COS strategies and standard starting dose strategy were included.

DATA COLLECTION AND ANALYSIS

Two reviews independently assessed the eligibility of retrieved citations in a predefined standardized manner. Relative risk (RRs) and the weighted mean difference (WMD) with 95% confidence intervals (CIs) were pooled using a random-effects model on R software version 4.2.2.

MAIN RESULTS

Compared with the standard dose COS strategy in pairwise meta-analysis, the individualized COS strategy was associated with a notable lower risk of ovarian hyperstimulation syndrome (OHSS; 174/2384 [7.30%] vs 114/2412 [4.73%], RR 0.66, 95% CI: 0.47-0.93, I2 = 46%), a significantly lower risk of hyperresponse to stimulation (hyperresponse; 476/2402 [19.82%] vs 331/2437 [13.58%], RR 0.71, 95% CI: 0.57-0.90, I2 = 61%), and a slightly longer ovarian stimulation days (duration of stimulation; WMD 0.20, 95% CI: 0.01-0.40, I2 = 66%). Bayesian network meta-analysis also found that biomarker-tailored strategy had a significantly lower risk of OHSS than standard dose strategy (OHSS; RR 0.63, 95% CI: 0.41-0.97, I2 = 47.5%).

CONCLUSION

Compared with standard dose COS strategy, individualized COS strategy could significantly reduce the risks of OHSS and hyperresponse to stimulation, but the duration of stimulation was slightly longer.

TRIAL REGISTRATION

PROSPERO: CRD42023358439.

Individualized dosing of follitropin delta affects live birth and safety in in vitro fertilization treatment: an individual participant data meta-analysis of randomized controlled trials

OBJECTIVE

To undertake a one-stage meta-analysis of individual patient data from randomized trials comparing individualized dosing of follitropin delta vs. other forms of follitropin (alpha and beta) for live birth (LB) rates (LBR) and safety parameters in women undergoing ovarian stimulation for in vitro fertilization treatment.

DESIGN

Systematic review with individual patient data meta-analysis.

SETTING

Not applicable.

PATIENTS

Women undergoing ovarian stimulation for in vitro fertilization treatment.

INTERVENTIONS

We searched MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, and the Web of Science to identify eligible phase 3 trials between January 1, 2000, and February 1, 2023.

MAIN OUTCOME MEASURES

All analyses were based on individual participant data. We used a general linear mixed effects logistic regression model using fixed effects for treatment drugs interacting with log (AMH) level, age, and random effects for country and trial to compare the primary efficacy and safety outcomes of LB and early ovarian hyperstimulation syndrome (OHSS) and/or the need for OHSS preventative measures, with ovarian stimulation parameters and neonatal outcomes also assessed. PROSPERO registration: CRD42023399711.

RESULTS

Three trials met inclusion criteria and included 2,685 women undertaking 2,682 cycles between October 2013 and May 2020, with LB follow-up through to February 1, 2023. For women with an elevated AMH level (≥15 pmol/L), there was high-quality evidence that the use of individualized dosing of follitropin delta was associated with an increased LB rate (adjusted odds ratio [adj OR] 1.64, 95% confidence interval [CI] 1.14, 2.36). Safety outcomes were also improved with a reduced risk of both early OHSS and/or the need for preventative interventions (adj OR 0.27, 95% CI 0.15, 0.49) and early moderate or severe OHSS (adj OR 0.30, 95% CI 0.16, 0.58). These improvements in outcomes were obtained with a lower total dose of gonadotropin (-48.7 μg, 95% CI -53.7, -43.8) and no adjustments in the daily dose. In contrast, similar LB rates (adj OR 0.86, 95% CI 0.63, 1.17) and safety outcomes (adj OR 1.92, 95% CI 0.76, 4.87) were observed for women with an AMH level of <15 pmol/L. There were no clinically meaningful differences in neonatal outcomes.

CONCLUSION

Using follitropin delta in an AMH level and weight-based algorithm rather than conventional licensed dosing of follitropin alpha or beta for ovarian stimulation in women is associated with improved LB rates and safety outcomes for women with elevated AMH levels.

A prospective proof-of-concept trial on the effect of personalized dosages of follitropin delta in intrauterine insemination

RESEARCH QUESTION

What is the efficacy and safety of individualized follitropin delta dosing for ovarian stimulation in intrauterine insemination (IUI)?

DESIGN

This single-centre, prospective, open-label, single-cohort study involving 106 patients established an original dosing regimen based on body weight and anti-Müllerian hormone (AMH) concentrations, with adjustments based on the ovarian response from the previous IUI cycle. Each participant was enrolled in a maximum of three IUI cycles.

RESULTS

Mean age was 34.5 ± 4.5 years, mean weight 69.2 ± 11.2 kg, mean AMH 15.7 ± 8.6 pmol/l, mean FSH 6.3 ± 2.6 IU/l and mean antral follicle count 16.4 ± 8.2. The percentage of patients who produced more than three mature follicles was 1.9%, 0% and 1.5%, respectively, for the three IUI cycles. The percentage of patients with two or three mature follicles was 34.0%, 36.9% and 47.1% for the three IUI cycles. The clinical pregnancy rate per IUI cycle was 17.9%, 14.3% and 17.6% for the three cycles, with a cumulative clinical pregnancy rate of 40.6%. Out of 258 cycles, 43 (16.7%) resulted in clinical pregnancy, with six of those resulting in multiple pregnancies (14.0%). Two resulted in spontaneous reduction within the first trimester and four resulted in live twin births, representing only 1.6% of the total cycles.

CONCLUSIONS

This study is the first to utilize follitropin delta for stimulation in IUI. It demonstrates that individualized dosing is both effective and safe, resulting in satisfactory cumulative pregnancy rates and an acceptable multiple pregnancy rate, thus achieving the primary objectives of the research.

Efficacy and safety of follitropin delta for ovarian stimulation in vitro fertilization/ intracytoplasmic sperm injection cycles: a systematic review with meta-analysis

BACKGROUND

Follitropin delta is a novel recombinant follicle stimulating hormone preparation uniquely expressed in a human fetal retinal cell line by recombinant DNA technology. To date, no systematic review was available about the safety and the efficacy of the follitropin delta. The objective of this study was systematically reviewing the available literature and to provide updated evidence regarding the efficacy-safety profile of follitropin delta when compared to other gonadotropin formulations for ovarian stimulation in in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) cycles.

METHODS

An extensive search was performed to identify phase 1, phase 2 and phase 3 RCTs in humans focused on follitropin delta use for ovarian stimulation in IVF/ICSI cycles. The risk of bias and the overall quality of the evidence was analyzed. All data were extracted and analyzed using the intention-to-treat principle and expressed per woman randomized.

RESULTS

A total of 7 RCTs (1 phase 1 RCT, 2 phase 2 RCTs and 4 phase 3 RCTs) were included in the qualitative analysis, whereas data of three phase 3 RCTs were meta-analyzed. All trials compared personalized recombinant follitropin delta treatment versus conventional recombinant follitropin alfa/beta administration in potentially normo-responder patients who receive ovarian stimulation in GnRH antagonist IVF/ICSI cycles. No difference between two regimens was detected for clinical pregnancy rate [odds ratio (OR) 1.06; 95% confidence intervals (CI): 0.90, 1.24; P = 0.49; I2 = 26%], ongoing pregnancy rate (OR 1.15; 95%CI: 0.90, 1.46; P = 0.27; I2 = 40%), and live birth rate (OR 1.18; 95%CI: 0.89, 1.55; P = 0.25; I2 = 55%). No data were available regarding cumulative success rates. The rate of adoption of strategies to prevent ovarian hyperstimulation syndrome (OHSS) development (OR 0.45; 95%CI: 0.30, 0.66; P < 0.0001; I2 = 0%), and the rate of both early OHSS (OR 0.62; 95%CI: 0.43, 0.88; P = 0.008; I2 = 0%) and all forms of OHSS (OR 0.61; 95%CI: 0.44, 0.84; P = 0.003; I2 = 0%) were significantly lower in the group of patients treated with personalized follitropin delta treatment compared to those treated with conventional follitropin alfa/beta administration.

CONCLUSION

Personalized follitropin delta treatment is associated with a lower risk of OHSS compared to conventional follitropin alfa/beta administration in potentially normo-responder patients who receive ovarian stimulation in GnRH antagonist IVF/ICSI cycles. The absence of cumulative data does not allow definitive conclusions to be drawn regarding the comparison of the effectiveness of the two treatments.

PROTOCOL STUDY REGISTRATION

CRD42023470352 (available at http://www.crd.york.ac.uk/PROSPERO ).

Anti-Mullerian Hormone Assessment in Assisted Reproductive Technique Outcome and Natural Conception

In recent years, the prevalence of infertility has increased, and appears to affect approximately one in six couples. Some of them must perform assisted reproductive techniques (ART) in order to achieve pregnancy. As a result, growing interest has arisen about predictive factors of pregnancy and live birth with and without ART. Anti-Mullerian hormone (AMH) is a glycoprotein discovered in the 1950s in male embryonic sexual differentiation. Later, in 1984, its role in folliculogenesis was reported: secreted by granulosa cells, this hormone is involved in the regulation of the recruitment of primordial follicles and in follicular growth. AMH assays were developed for women in 1990s, and the serum AMH level has rapidly become a crucial element in managing women's fertility. Based mainly on its ability to be a quantitative but indirect marker of ovarian reserve, the serum AMH assay is widely used in reproductive medicine and ART. This review summarizes current knowledge of the AMH assessment in the field of reproductive medicine. We focus on the role of AMH level to predict spontaneous pregnancy occurrence, ART outcomes, and fertility preservation outcomes.

The prospect of artificial intelligence to personalize assisted reproductive technology

Infertility affects 1-in-6 couples, with repeated intensive cycles of assisted reproductive technology (ART) required by many to achieve a desired live birth. In ART, typically, clinicians and laboratory staff consider patient characteristics, previous treatment responses, and ongoing monitoring to determine treatment decisions. However, the reproducibility, weighting, and interpretation of these characteristics are contentious, and highly operator-dependent, resulting in considerable reliance on clinical experience. Artificial intelligence (AI) is ideally suited to handle, process, and analyze large, dynamic, temporal datasets with multiple intermediary outcomes that are generated during an ART cycle. Here, we review how AI has demonstrated potential for optimization and personalization of key steps in a reproducible manner, including: drug selection and dosing, cycle monitoring, induction of oocyte maturation, and selection of the most competent gametes and embryos, to improve the overall efficacy and safety of ART.

Prospective multicenter observational real-world study to assess the use, efficacy and safety profile of follitropin delta during IVF/ICSI procedures (DELTA Study)

OBJECTIVE

To describe the use, efficacy and safety profile of follitropin delta in women undergoing IVF/ICSI in routine clinical practice after one treatment cycle.

STUDY DESIGN

This was a French multicenter, prospective, observational study conducted in 14 fertility centers between June 2020 and June 2021. During this period, 248 women undergoing IVF or ICSI were treated with follitropin delta for the first time. Women were followed up to 10-11 weeks after the first fresh or frozen embryo transfer. The main outcomes were use of dosing algorithm, follitropin delta dosing patterns, ovarian response, pregnancy, and adverse drug reactions in routine clinical practice.

RESULTS

The analyzable population consisted of 223 patients with mean ± SD age of 33.0 ± 4.4 years, body weight of 65.7 ± 11.8 kg, and the median (IQR) AMH level was 2.6 (1.5-4.0) ng/mL. For 193 patients (86.5 %) it was the first IVF/ICSI cycle and for 30 (13.5 %) the second. The algorithm was used for the calculation of the starting dose for 88.3 % of the patients. The mean daily starting dose of follitropin delta was 11.4 ± 4.1mcg for the whole analyzable population and 14.4 ± 5.2 mcg for the sub-group of 26 patients dosed without the algorithm. The mean duration of stimulation with follitropin delta was 10.8 ± 5.2 days. The mean total dose of follitropin delta administered was 122.2 ± 80.0 mcg. An antagonist protocol was used in 90.3 % of patients. The mean ± SD number of oocytes retrieved among patients that started stimulation was 11.3 ± 6.8 and 46.1 % of patients achieved the targeted response of the algorithm of 8-14 oocytes retrieved. A fresh transfer was performed for 77.6 % of patients; the mean ± SD number of embryos transferred was 1.3 ± 0.5. The implantation rate was 36.0 %. Per started cycle, clinical pregnancy was reported in 35.0 % of the patients and ongoing pregnancy in 29.6 %. In total, 5 patients (2.2 %) reported an event of OHSS.

CONCLUSION

Clinical results as collected in routine clinical practice are promising, showing a favorable effectiveness-safety profile of follitropin delta for a very varied patient population (including anovulatory PCOS, very poor responders, or non-IVF naïve patients). These real-world data complement results from clinical trials and provide useful information for usual clinical practice within a heterogeneous population group.

Prevention of moderate and severe ovarian hyperstimulation syndrome: a guideline

Ovarian hyperstimulation syndrome is a serious complication associated with assisted reproductive technology. This systematic review aims to identify who is at high risk for developing ovarian hyperstimulation syndrome, along with evidence-based strategies to prevent it and replaces the document of the same name last published in 2016.

Personalizing the first dose of FSH for IVF/ICSI patients through machine learning: a non-inferiority study protocol for a multi-center randomized controlled trial

BACKGROUND

Adequately selecting the initial follicle-stimulating hormone (FSH) dose during controlled ovarian stimulation (COS) is key for success in assisted reproduction. The objective of COS is to obtain an optimal number of oocytes to increase the chances of achieving a pregnancy, while avoiding complications for the patient. Current clinical protocols do achieve good results for the majority of patients, but further refinements in individualized FSH dosing may reduce the risk of poor ovarian response while also limiting the risk of ovarian hyperstimulation syndrome (OHSS) risk. Models to select the first FSH dose in COS have been presented in literature with promising results. However, most have only been developed and tested in normo-ovulatory women under the age of 40 years.

METHODS

This is a randomized, controlled, multicenter, single blinded, clinical trial. This study will be performed in 236 first cycle in vitro fertilization (IVF) and/or ICSI (intracytoplasmic sperm injection) patients, randomized 1:1 in two arms. In the intervention arm, the dose of FSH will be assigned by a machine learning (ML) model called IDoser, while in the control arm, the dose will be determined by the clinician following standard practice. Stratified block randomization will be carried out depending on the patient being classified as expected low responder, high responder, or normo-responder. Patients will complete their participation in the trial once the first embryo transfer result is known. The primary outcome of the study is the number of metaphase II (MII) oocytes retrieved at ovarian pick up (OPU) and the hypothesis of non-inferiority of the intervention arm compared to the control. Secondary outcomes include the number of cycle cancelations (due to low response or no retrieval of mature oocytes), risk of ovarian hyperstimulation syndrome (OHSS), and clinical pregnancy and live birth rates per first transfer.

DISCUSSION

To our knowledge, this is the first randomized trial to test clinical performance of an all-patient inclusive model to select the first dose of FSH for COS. Prospective trials for machine learning (ML) models in healthcare are scarce but necessary for clinical application.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT05948293 . Registered on 14 July 2023.

Individualised gonadotropin dose selection using markers of ovarian reserve for women undergoing in vitro fertilisation plus intracytoplasmic sperm injection (IVF/ICSI)

BACKGROUND

During a stimulated cycle of in vitro fertilisation or intracytoplasmic sperm injection (IVF/ICSI), women receive daily doses of gonadotropin follicle-stimulating hormone (FSH) to induce multifollicular development in the ovaries. A normal response to stimulation (e.g. retrieval of 5 to 15 oocytes) is considered desirable. Generally, the number of eggs retrieved is associated with the dose of FSH. Both hyper-response and poor response are associated with an increased chance of cycle cancellation. In hyper-response, this is due to increased risk of ovarian hyperstimulation syndrome (OHSS), while poor response cycles are cancelled because the quantity and quality of oocytes is expected to be low. Clinicians often individualise the FSH dose using patient characteristics predictive of ovarian response. Traditionally, this meant women's age, but increasingly, clinicians use various ovarian reserve tests (ORTs). These include basal FSH (bFSH), antral follicle count (AFC), and anti-Müllerian hormone (AMH). It is unclear whether individualising FSH dose improves clinical outcomes. This review updates the 2018 version.

OBJECTIVES

To assess the effects of individualised gonadotropin dose selection using markers of ovarian reserve in women undergoing IVF/ICSI.

SEARCH METHODS

We searched the Cochrane Gynaecology and Fertility Group Specialised Register of controlled trials, CENTRAL, MEDLINE, Embase, and two trial registers in February 2023.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared (a) different doses of FSH in women with a defined ORT profile (i.e. predicted low, normal, or high responders based on AMH, AFC, and/or bFSH) or (b) an individualised dosing strategy (based on at least one ORT measure) versus uniform dosing or a different individualised dosing algorithm.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. Primary outcomes were live birth/ongoing pregnancy and severe OHSS.

MAIN RESULTS

We included 26 studies, involving 8520 women (6 new studies added to 20 studies included in the previous version). We treated RCTs with multiple comparisons as separate trials for the purpose of this review. Meta-analysis was limited due to clinical heterogeneity. Evidence certainty ranged from very low to low, with the main limitations being imprecision and risk of bias associated with lack of blinding. Direct dose comparisons according to predicted response in women Due to differences in dose comparisons, caution is required when interpreting the RCTs in predicted low responders. All evidence was low or very low certainty. Effect estimates were very imprecise, and increased FSH dosing may or may not have an impact on rates of live birth/ongoing pregnancy, OHSS, and clinical pregnancy. Similarly, in predicted normal responders (10 studies, 4 comparisons), higher doses may or may not impact the probability of live birth/ongoing pregnancy (e.g. 200 versus 100 international units (IU): odds ratio (OR) 0.88, 95% confidence interval (CI) 0.57 to 1.36; I2 = 0%; 2 studies, 522 women) or clinical pregnancy. Results were imprecise, and a small benefit or harm remains possible. There were too few events for the OHSS outcome to enable inferences. In predicted high responders, lower doses may or may not affect live birth/ongoing pregnancy (OR 0.98, 95% CI 0.66 to 1.46; 1 study, 521 women), severe OHSS, and clinical pregnancy. It is also unclear whether lower doses reduce moderate or severe OHSS (Peto OR 2.31, 95% CI 0.80 to 6.67; 1 study, 521 participants). ORT-algorithm studies Eight trials compared an ORT-based algorithm to a non-ORT control group. It is unclear whether live birth/ongoing pregnancy and clinical pregnancy are increased using an ORT-based algorithm (live birth/ongoing pregnancy: OR 1.12, 95% CI 0.98 to 1.29; I2 = 30%; 7 studies, 4400 women; clinical pregnancy: OR 1.04, 95% CI 0.91 to 1.18; I2 = 18%; 7 studies, 4400 women; low-certainty evidence). However, ORT algorithms may reduce moderate or severe OHSS (Peto OR 0.60, 95% CI 0.42 to 0.84; I2 = 0%; 7 studies, 4400 women; low-certainty evidence). There was insufficient evidence to determine whether the groups differed in rates of severe OHSS (Peto OR 0.74, 95% CI 0.42 to 1.28; I2 = 0%; 5 studies, 2724 women; low-certainty evidence). Our findings suggest that if the chance of live birth with a standard starting dose is 25%, the chance with ORT-based dosing would be between 25% and 31%. If the chance of moderate or severe OHSS with a standard starting dose is 5%, the chance with ORT-based dosing would be between 2% and 5%. These results should be treated cautiously due to heterogeneity in the algorithms: some algorithms appear to be more effective than others.

AUTHORS' CONCLUSIONS

We did not find that tailoring the FSH dose in any particular ORT population (low, normal, high ORT) affected live birth/ongoing pregnancy rates, but we could not rule out differences, due to sample size limitations. Low-certainty evidence suggests that it is unclear if ORT-based individualisation leads to an increase in live birth/ongoing pregnancy rates compared to a policy of giving all women 150 IU. The confidence interval is consistent with an increase of up to around six percentage points with ORT-based dosing (e.g. from 25% to 31%) or a very small decrease (< 1%). A difference of this magnitude could be important to many women. It is unclear if this is driven by improved outcomes in a particular subgroup. Further, ORT algorithms reduced the incidence of OHSS compared to standard dosing of 150 IU. However, the size of the effect is also unclear. The included studies were heterogeneous in design, which limited the interpretation of pooled estimates. It is likely that different ORT algorithms differ in their effectiveness. Current evidence does not provide a clear justification for adjusting the dose of 150 IU in poor or normal responders, especially as increased dose is associated with greater total FSH dose and cost. It is unclear whether a decreased dose in predicted high responders reduces OHSS, although this would appear to be the most likely explanation for the results.

Follitropin delta combined with menotropin in patients at risk for poor ovarian response during in vitro fertilization cycles: a prospective controlled clinical study

BACKGROUND

The maximum daily dose of follitropin delta for ovarian stimulation in the first in vitro fertilization cycle is 12 μg (180 IU), according to the algorithm developed by the manufacturer, and based on patient's ovarian reserve and weight. This study aimed to assess whether 150 IU of menotropin combined with follitropin delta improves the response to stimulation in women with serum antimullerian hormone levels less than 2.1 ng/mL.

METHODS

This study involved a prospective intervention group of 44 women who received 12 μg of follitropin delta combined with 150 IU of menotropin from the beginning of stimulation and a retrospective control group of 297 women who received 12 μg of follitropin delta alone during the phase 3 study of this drug. The inclusion and exclusion criteria and other treatment and follow-up protocols in the two groups were similar. The pituitary suppression was achieved by administering a gonadotropin-releasing hormone (GnRH) antagonist. Ovulation triggering with human chorionic gonadotropin or GnRH agonist and the option of transferring fresh embryos or using freeze-all strategy were made according to the risk of developing ovarian hyperstimulation syndrome.

RESULTS

Women who received follitropin delta combined with menotropin had higher estradiol levels on trigger day (2150 pg/mL vs. 1373 pg/mL, p < 0.001), more blastocysts (3.1 vs. 2.4, p = 0.003) and more top-quality blastocysts (1.8 vs. 1.3, p = 0.017). No difference was observed in pregnancy, implantation, miscarriage, and live birth rates after the first embryo transfer. The incidence of ovarian hyperstimulation syndrome did not differ between the groups. However, preventive measures for the syndrome were more frequent in the group using both drugs than in the control group (13.6% vs. 0.6%, p < 0.001).

CONCLUSIONS

In women with serum antimullerian hormone levels less than 2.1 ng/mL, the administration of 150 IU of menotropin combined with 12 μg of follitropin delta improved the ovarian response, making it a valid therapeutic option in situations where ovulation triggering with a GnRH agonist and freeze-all embryos strategy can be used routinely.

TRIAL REGISTRATION

U1111-1247-3260 (Brazilian Register of Clinical Trials, available at https://ensaiosclinicos.gov.br/rg/RBR-2kmyfm ).

Anti-Müllerian hormone for screening, diagnosis, evaluation, and prediction: A systematic review and expert opinions

AIM

To present evidence-based recommendations for anti-Müllerian hormone (AMH) measurement as an ovarian reserve test.

METHODS

A systematic literature search for the clinical utility of AMH was conducted in PubMed from its inception to August 2022 to identify studies, including meta-analyses, reviews, randomized controlled trials, and clinical trials, followed by an additional systematic search using keywords. Based on this evidence, an expert panel developed clinical questions (CQs).

RESULTS

A total of 1895 studies were identified and 95 articles were included to establish expert opinions subdivided into general population, infertility treatment, primary ovarian insufficiency, polycystic ovary syndrome, surgery, and oncofertility. We developed 13 CQs and 1 future research question with levels of evidence and recommendations.

CONCLUSION

The findings of the current systematic review covered the clinical utility of AMH including its screening, diagnosis, evaluation, and prediction. Although some clinical implications of AMH remain debatable, these expert opinions may help promote a better understanding of AMH and establish its clinical significance.

Efficacy and safety of follitropin delta versus follitropin alpha/beta in infertility treatment: A systematic review and meta-analysis

Background

Follitropin δ may be an alternative to conventional follitropin α/β for controlled ovarian stimulation (COS) within assisted reproductive treatment (ART), but its efficacy and safety remain unknown. We performed a random-effects meta-analysis to compare the efficacy and safety of follitropin δ and follitropin α/β.

Methods

We searched randomized controlled trials comparing follitropin δ and follitropin α/β using MEDLINE, Embase, CENTRAL, ClinicalTrials.gov, and WHO-ITCRP on December 14, 2022. The primary outcomes were the live birth rate and the incidence of moderate or severe ovarian hyperstimulation syndrome (OHSS). The certainty of the evidence was assessed using the grading of recommendations assessment, development, and evaluation approach. The protocol was registered on the Open Science Framework.

Results

Three studies involving 2682 participants were included in our meta-analysis. The results indicated that follitropin δ may result in little to no difference in live birth rates (risk ratio [RR], 1.12; 95% confidence interval [CI], 0.91-1.38; low certainty) and the incidence of moderate or severe OHSS (RR, 0.78; 95% CI, 0.48-1.26; low certainty) compared with follitropin α/β.

Conclusion

Follitropin δ may result in little to no difference in COS compared with follitropin α/β, especially in terms of live births and safety.

FSH administration at 12-hour intervals for the first 2 days, combined with mandatory GnRH-agonist trigger and blastocyst vitrification in women (<80Kg) with high AMH levels, results in higher cumulative live birth rates and is safer

We aimed to determine if a programme change to 12 hourly injections of FSH (150 IU per injection) for the first 2 days of stimulation in women with high ovarian reserve (AMH ≥ 30 pmol/L), followed by 24 hourly injections, would elicit increased earlier follicular recruitment, higher egg yields and blastocyst embryos for cryopreservation, leading to potential higher cumulative pregnancy rates, than conventional daily injections throughout. For safety reasons, the approach required mandatory cryopreservation of all blastocysts (mFET group; n = 74), after ovulation trigger with GnRH-agonist, in GnRH-antagonist controlled cycles. The 'Comparator group' (n = 91) comprised women with the same high AMH levels treated with the same base dose of FSH, with the aim of fresh blastocyst transfer and cryopreservation of supernumerary embryos, treated over the preceding 2 years. There was no difference in age, AMH, weight or BMI between the groups. The mFET group achieved higher egg (17.7 versus 11.7; p < 0.001) and embryo (10.9 versus 7.2; p < 0.001) yields and fewer cases with sub-optimal embryo yields (7% versus 22%; p = 0.018). The cumulative live birth rate was superior in the mFET group (73% versus 43%), as was the safety profile, and negligible rate of treatment plan modification.

Incidence and severity of ovarian hyperstimulation syndrome (OHSS) in high responders after gonadotropin-releasing hormone (GnRH) agonist trigger in "freeze-all" approach

OBJECTIVE

To determine the incidence and severity of ovarian hyperstimulation syndrome (OHSS) in high responders (25-35 follicles with a diameter of ≥12 mm on day of triggering) who received a gonadotropin-releasing hormone (GnRH) agonist to trigger final follicular maturation.

METHODS

We used individual data from women who participated in four different clinical trials and were high responders to ovarian stimulation in a GnRH antagonist protocol in this retrospective combined analysis. All women were evaluated for signs and symptoms of OHSS using identical criteria based on Golan's system (1989).

RESULTS

High responders (n = 77) were of different ethnicities. There were no differences in baseline characteristics between women with or without signs and symptoms of OHSS. Mean ± standard deviation baseline data were: age, 32.3 ± 3.5 years; anti-Müllerian hormone, 42.4 ± 20.7 pmol/L; antral follicle count, 21.5 ± 9.2. Before triggering, duration of stimulation was 9.5 ± 1.6 days and the mean number of follicles with a diameter of ≥12 mm and ≥17 mm was 26.5 ± 4.4 and 8.8 ± 4.7, respectively. Mean serum estradiol (17,159 pmol/l) and progesterone (5.1 nmol/l) levels were high at 36 h after triggering. Overall, 17/77 high responders (22%) developed signs and symptoms of mild OHSS which lasted 6-21 days. The most frequently prescribed medication was cabergoline to prevent worsening of OHSS. No severe OHSS occurred and no OHSS cases were reported as serious adverse events.

CONCLUSIONS

High responders receiving GnRH agonist for triggering should be informed that they may experience signs and symptoms of mild OHSS.

Pre-Vitrification and Post-Warming Variables of Vitrified-Warmed Blastocysts That Are Predictable for Implantation

Human IVF embryos that are not used for fresh transfer are cryopreserved by vitrification for later embryo transfers. This study evaluates pre-vitrification and post-warming embryo characteristics that are suitable to predict the chance of clinical pregnancy in single vitrified blastocyst transfer (SVBT) cycles. In a multicenter observational trial (IMBOS trial), embryos were cultured in a time-lapse system before and after vitrification. Associations between clinical pregnancy, morphokinetic parameters, blastocyst collapse, KIDScore D5, pre-vitrification and post-warming Gardner scores, post-warming blastocyst size and re-expansion rates before SVBT were analyzed in 182 SVBTs which resulted in 89 clinical pregnancies. No association was found between clinical pregnancy after SVBT and the number of collapses or the maximal collapse size before vitrification. The multifactorial analysis of pre-vitrification Gardner scores showed a significant association with clinical pregnancy for trophectoderm grading but not for expansion/hatching status and inner cell mass grading. A significant association with clinical pregnancy was found for the time to reach a blastocyst after pronuclear fading (tB-tPNf), KIDScore D5 and post-warming size but not the rate of expansion or maximal expansion size. The selection of blastocysts for SVBT could benefit from using pre-vitrification parameters like tB-tPNf, trophectoderm grading and post-warming blastocyst size.

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.

Using serum anti-Müllerian hormone levels to predict the chance of live birth after spontaneous or assisted conception: a systematic review and meta-analysis

STUDY QUESTION

Is serum anti-Müllerian hormone (AMH) level predictive of cumulative live birth (CLB) rate after ART or in women trying to conceive naturally?

SUMMARY ANSWER

Serum AMH level is linked to CLB after IVF/ICSI but data are lacking after IUI or in women trying to conceive without ART.

WHAT IS KNOWN ALREADY

Serum AMH level is a marker of ovarian reserve and a good predictor of ovarian response after controlled ovarian stimulation. It is unclear whether AMH measurement can predict CLB in spontaneous or assisted conception.

STUDY DESIGN, SIZE, DURATION

A systematic review and meta-analysis was undertaken to assess whether serum AMH level may predict chances of CLB in infertile women undergoing IVF/ICSI or IUI and/or chances of live birth in women having conceived naturally.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A systematic review and meta-analysis was performed using the following keywords: 'AMH', 'anti-mullerian hormone', 'live-birth', 'cumulative live birth'. Searches were conducted from January 2004 to April 2021 on PubMed and Embase. Two independent reviewers carried out study selection, quality, and risk of bias assessment as well as data extraction. Odds ratios were estimated using a random-effect model. Pre-specified sensitivity analyses and subgroup analyses were performed. The primary outcome was CLB.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 32 studies were included in the meta-analysis. Overall, 27 articles were included in the meta-analysis of the relation between AMH and CLB or AMH and LB after IVF/ICSI. A non-linear positive relation was found in both cases. A polynomial fraction was the best model to describe it but no discriminant AMH threshold was shown, especially no serum AMH level threshold below which live birth could not be achieved after IVF/ICSI. After IVF-ICSI, only four studies reported CLB rate according to AMH level. No statistically significant differences in mean serum AMH levels were shown between patients with and without CLB, but with a high heterogeneity. After exclusion of two studies with high risks of bias, there was no more heterogeneity [I2 = 0%] and the mean AMH level was statistically significantly higher in women with CLB. There were not enough articles/data to assess the ability of AMH to predict CLB rate or find an AMH threshold after IUI or in women without history of infertility trying to conceive without ART.

LIMITATIONS, REASONS FOR CAUTION

The systematic review and meta-analysis had some limitations owing to the limits and bias of the studies included. In the present meta-analysis, heterogeneity may have been caused by different baseline characteristics in study participants, different stimulating protocols for ART, different serum AMH level thresholds used and the use of various assays for serum AMH. This could explain, in part, the absence of a discriminating AMH threshold found in this analysis.

WIDER IMPLICATIONS OF THE FINDINGS

Serum AMH level is linked to CLB rate after IVF/ICSI but no discriminating threshold can be established, therefore low serum AMH level should not be used as the sole criterion for rejecting IVF treatment, especially in young patients. Data are lacking concerning its predictive value after IUI or in women trying to conceive without ART. Our findings may be helpful to counsel candidate couples to IVF-ICSI.

STUDY FUNDING/COMPETING INTERESTS

No external funding was obtained for this study. There are no conflicts of interest.

REGISTRATION NUMBER

PROSPERO CRD42021269332.

Fine-tuning the dose of recombinant human follicle-stimulating hormone alfa to individualize treatment in ovulation induction and ovarian stimulation cycles: a real-world database analysis

Introduction

Fine-tuning of injectable gonadotropin doses during ovulation induction (OI) or ovarian stimulation (OS) treatment cycles with the aim of using doses low enough to minimize the risk of excessive ovarian response while maintaining optimal efficacy may be facilitated by using an adjustable-dose pen injector. We examined the incidence and magnitude of individualized gonadotropin dose adjustments made during cycles of OI or OS, followed by either timed intercourse or intrauterine insemination, with or without oral medications, and assessed the relationship between patient characteristics and dosing changes using real-world evidence.

Methods

This was an observational, retrospective cohort study using electronic medical records from a large US database of fertility centers. Data from patients who had undergone a first recombinant human follicle stimulating hormone alfa (r-hFSH-alfa/follitropin alfa) treated OI/OS cycle followed by timed intercourse or intrauterine insemination between 2015 and 2016 were included. Percentages of OI/OS cycles involving r-hFSH-alfa dose adjustments (in increments of ±12.5 IU or greater) with or without oral medications (clomiphene citrate or letrozole) were analyzed.

Results

Of 2,832 OI/OS cycles involving r-hFSH-alfa administration, 74.6% included combination treatment with orals; 25.4% involved r-hFSH-alfa alone. As expected, the starting dose of r-hFSH-alfa was lower for cycles that used r-hFSH-alfa with orals than r-hFSH-alfa only cycles (mean [SD]: 74.2 [39.31] vs 139.3 [115.10] IU). Dose changes occurred in 13.7% of r-hFSH-alfa with orals versus 43.9% of r-hFSH-alfa only cycles. Dose adjustment magnitudes ranged from ±12.5 IU to ±450 IU. The smallest adjustment magnitudes (±12.5 IU and ±25 IU) were used frequently and more often for dose increases than for dose decreases. For r-hFSH-alfa with orals and r-hFSH-alfa only cycles, the smallest adjustments were used in 53.5% and 64.5% of cycles with dose increases and in 35.7% and 46.8% of cycles with dose decreases, respectively.

Discussion

In OI/OS cycles followed by timed intercourse or intrauterine insemination, r-hFSH-alfa dose adjustments were frequent. In cycles that included orals, r-hFSH-alfa starting doses were lower and dose changes were fewer than with r-hFSH-alfa alone. Smaller dose adjustments facilitate individualized treatment with the goal of reducing the risks of multiple gestation, cycle cancellation, and ovarian hyperstimulation syndrome.

Inadvertent Administration of 72 µg of Follitropin-Δ for Three Consecutive Days Does Not Appear to Be Dangerous for Poor Responders: A Case Series

Follitropin delta (Δ) is a recombinant human follicle-stimulating hormone (rFSH), like natural human FSH, that can stimulate the development and growth of multiple follicles. Treatment with Follitropin-Δ may cause mild to severe adverse reactions, such as the risk of developing ovarian hyperstimulation syndrome, resulting in nausea, vomiting and diarrhea, weight loss, respiratory difficulty, stomach swelling and discomfort of the pelvic area, headaches, and fatigue. To date, the effects of a Follitropin-Δ overdosage are unknown, and no data are reported in the scientific literature or in the drug data sheet. Therefore, this study aimed to describe the effects of Follitropin-Δ overdosages in poorly responding women who underwent IVF cycles. This is a descriptive case series of four nulligravid, poorly responding patients, two of whom made requests for fertility preservation. Four poorly responding patients who were prescribed 20.0 µg/day of Follitropin-Δ for three consecutive days wrongly injected the total cartridge of 72 µg Follitropin-Δ every day. After the incorrect injection of Follitropin-Δ, the patients continued their controlled ovarian stimulation and underwent vaginal ovarian pick up. The analyzed patients had no side effects or adverse reactions. The evaluations reported in this case series showed that the accidental use of 72 µg/day of Follitropin-Δ for three days did not cause side effects or adverse reactions in poor responders.

Interventions to prevent or reduce the incidence and severity of ovarian hyperstimulation syndrome: a systematic umbrella review of the best clinical evidence

Ovarian hyperstimulation syndrome (OHSS) is a potentially life-threating iatrogenic complication of the early luteal phase and/or early pregnancy after in vitro fertilization (IVF) treatment. The aim of the current study was to identify the most effective methods for preventing of and reducing the incidence and severity of OHSS in IVF patients. A systematic review of systematic reviews of randomized controlled trials (RCTs) with meta-analysis was used to assess each potential intervention (PROSPERO website, CRD 268626) and only studies with the highest quality were included in the qualitative analysis. Primary outcomes included prevention and reduction of OHSS incidence and severity. Secondary outcomes were maternal death, incidence of hospital admission, days of hospitalization, and reproductive outcomes, such as incidence of live-births, clinical pregnancies, pregnancy rate, ongoing pregnancy, miscarriages, and oocytes retrieved. A total of specific interventions related to OHSS were analyzed in 28 systematic reviews of RCTs with meta-analyses. The quality assessment of the included studies was high, moderate, and low for 23, 2, and 3 studies, respectively. The certainty of evidence (CoE) for interventions was reported for 37 specific situations/populations and resulted high, moderate, and low-to-very low for one, 5, and 26 cases, respectively, while it was not reported in 5 cases. Considering the effective interventions without deleterious reproductive effects, GnRH-ant co-treatment (36 RCTs; OR 0.61, 95% C 0.51 to 0.72, n = 7,944; I² = 31%) and GnRH agonist triggering (8 RCTs; OR 0.15, 95% CI 0.05 to 0.47, n = 989; I² = 42%) emerged as the most effective interventions for preventing OHSS with a moderate CoE, even though elective embryo cryopreservation exhibited a low CoE. Furthermore, the use of mild ovarian stimulation (9 RCTs; RR 0.26, CI 0.14 to 0.49, n = 1,925; I² = 0%), and dopaminergic agonists (10 RCTs; OR 0.32, 95% CI 0.23 to 0.44, n = 1,202; I² = 13%) coadministration proved effective and safe with a moderate CoE. In conclusion, the current study demonstrates that only a few interventions currently can be considered effective to reduce the incidence of OHSS and its severity with high/moderate CoE despite the numerous published studies on the topic. Further well-designed RCTs are needed, particularly for GnRH-a down-regulated IVF cycles.

Follicle-Stimulating Hormone Biological Products: Does Potency Predict Clinical Efficacy?

Follicle-stimulating hormone (FSH), together with luteinizing hormone (LH) and human chorionic gonadotropin (hCG), plays a fundamental role in human reproduction. The discovery of FSH and other gonadotropins was a defining moment in our understanding of reproduction and led to the development of many treatments for infertility. In this regard, exogenous FSH has been used to treat infertility in women for decades. Today, several recombinant and highly purified urinary forms of FSH are used in medically assisted reproduction (MAR). However, differences in the macro- and micro-heterogeneity of FSH result in a variety of FSH glycoforms, with glycoform composition determining the bioactivity (or potency), pharmacokinetic/pharmacodynamic (PK/PD) profiles, and clinical efficacy of the different forms of FSH. This review illustrates how the structural heterogeneity of FSH glycoforms affects the biological activity of human FSH products, and why potency does not predict effects in humans in terms of PK, PD, and clinical response.

Live birth rates following individualized dosing algorithm of follitropin delta in a long GnRH agonist protocol

PURPOSE

To explore the efficacy and safety of individualized follitropin delta dosing, based on serum anti-Müllerian hormone (AMH) concentration and bodyweight, in a long gonadotropin-releasing hormone (GnRH) agonist protocol.

METHODS

Clinical outcomes after one treatment cycle are reported in women with AMH: 5-35 pmol/L. Oocytes were inseminated by intracytoplasmic sperm injection, blastocyst transfer was on Day 5 and remaining blastocysts were cryopreserved. Data collection included live births and neonatal health follow-up for all fresh/frozen transfers performed within one year after treatment allocation.

RESULTS

In total, 104 women started stimulation, of whom 101 had oocyte recovery and 92 had blastocyst transfer. The average daily dose of follitropin delta was 11.0 ± 1.6 µg and the duration of stimulation was 10.3 ± 1.6 days. The mean number of oocytes was 12.5 ± 6.4, the mean number of blastocysts was 5.1 ± 3.4, and 85% had at least one good-quality blastocyst. Following mostly single blastocyst transfer (95%), the ongoing pregnancy rate was 43%, the live-birth rate was 43%, and the cumulative live-birth rate was 58% per started stimulation. There were 6 cases of early OHSS (5.8%) graded as mild (n = 3) and moderate (n = 3) and 6 cases of late OHSS (5.8%) graded as moderate (n = 3) and severe (n = 3).

CONCLUSION

In this first evaluation of the individualized follitropin delta dosing in a long GnRH agonist protocol, the cumulative live-birth rate was high. A randomized trial comparing follitropin delta in a long GnRH agonist protocol versus in a GnRH antagonist protocol should provide further insight into the efficacy and safety of this treatment option.

TRIAL REGISTRATION NUMBER

NCT03564509; June 21, 2018.

Treatment algorithms for high responders: What we can learn from randomized controlled trials, real-world data and models

A high ovarian response to conventional ovarian stimulation (OS) is characterized by an increased number of follicles and/or oocytes compared with a normal response (10-15 oocytes retrieved). According to current definitions, a high response can be diagnosed before oocyte pick-up when >18-20 follicles ≥11-12 mm are observed on the day of ovulation triggering; high response can be diagnosed after oocyte pick-up when >18-20 oocytes have been retrieved. Women with a high response are also at high risk of early ovarian hyper-stimulation syndrome (OHSS)/or late OHSS after fresh embryo transfers. Women at risk of high response can be diagnosed before stimulation based on several indices, including ovarian reserve markers (anti-Müllerian hormone [AMH] and antral follicle count [AFC], with cutoff values indicative of a high response in patients with PCOS of >3.4 ng/mL for AMH and >24 for AFC). Owing to the high proportion of high responders who are at the risk of developing OHSS (up to 30%), this educational article provides a framework for the identification and management of patients who fall into this category. The risk of high response can be greatly reduced through appropriate management, such as individualized choice of the gonadotropin starting dose, dose adjustment based on hormonal and ultrasound monitoring during OS, the choice of down-regulation protocol and ovulation trigger, and the choice between fresh or elective frozen embryo transfer. Appropriate management strategies still need to be defined for women who are predicted to have a high response and those who have an unexpected high response after starting treatment.

How to dose follitropin delta for the first insemination cycle according to the ESHRE and ASRM guidelines; a retrospective cohort study

BACKGROUND

Follitropin Delta (FD) is indicated exclusively for in-vitro fertilization however, being a gonadotropin it could be used for other purposes. A dosing algorithm exists for FD and IVF but is needed for intrauterine insemination (IUI) cycles. The objective of this study is to determine dosing for FD for the first controlled ovarian hyperstimulation (COH) cycle according to current stimulation guidelines.

RESULTS

A retrospective study of 157 subjects from a single university fertility center from January 2017 to March 2020, was performed. All patients stimulated with FD for IUI were included. The number of failed, normal, or overstimulation cycles was determined based on stimulating not more than 2 mature follicles. We then stratified the group based on the AFC, AMH, and body weight. Of 157 subjects, 49% stimulated correctly, 5.6% failed and 45.4% overstimulated. An analysis of the COH IUI cycles based on stratification and over or lack of stimulation per published guidelines found that women with a bodyweight < 80 kg or AMH ≥ 1.5 ng/ml or AFC ≥ 10 initially stimulate with FD 2.0 to 3.0mcg daily. For women with an AFC of 6-9 stimulate with Follitropin Delta 3.0mcg daily. For women with an AFC < 6 or serum AMH < 1.5 ng/ml stimulate with FD 3.0-4.0mcg daily. For women with body weight > 80 kg stimulate initially with daily with 4.0-6.0mcg FD.

CONCLUSIONS

Follitropin Delta can be used safely for controlled ovarian stimulation and insemination at doses easily dispensed by the current methods of delivery, within the current published guidelines for follicle development.

A Narrative Review Discussing the Efficiency of Personalized Dosing Algorithm of Follitropin Delta for Ovarian Stimulation and the Reproductive and Clinical Outcomes

Background: Follitropin delta is the third recombinant human follicle-stimulating hormone (r-hFSH) expressed in a host cell line of human fetal retinal origin that currently emphasizes that the actual tendency of administration is a personalized dosing algorithm based on the anti-Müllerian hormone (AMH) and body mass index (BMI) for ovarian stimulation. Methods: In this context, we aimed, in the present manuscript, to gather all available data published between 2018-2022 regarding the co-administration and administration of follitropin delta and the clinical outcomes reported following an in vitro fertilization (IVF). Results: Follitropin delta is non-inferior in contrast to its previously launched agents for ovarian stimulation, enhancing a similar-to-superior response reflected by both the reproductive and pregnancy outcomes in parallel with a low risk of ovarian hyperstimulation syndrome (OHSS), being well tolerated. The body weight and AMH level are factors that may influence the outcome in a patient. Despite controversy and results that refute these arguments on several occasions, follitropin delta exceeds the benefits of conventional dosing with either follitropin alfa or follitropin beta. Thus, all post hoc, derived analyses and subsets of patients that participated in subsequent studies support this statement. Conclusions: Despite the relatively limited spectrum of data in the current literature, most authors brought potent proof, supporting the subsequent use of this drug depending on the patient's profile and overcoming ethnic-related limitations. Although others contradict these observations, this topic and drug possess substantial potential, which is why additional studies are mandatory to fill the existing gaps in our knowledge and expand these experiences at a larger scale supported by the obtained reproductive and clinical outcomes that clearly indicate an overcoming of all limitations.

A real-world study of ART in France (REOLA) comparing a biosimilar rFSH against the originator according to rFSH starting dose

BACKGROUND

Since the first launch of a biosimilar recombinant follicle stimulating hormone (rFSH), Bemfola®, in Europe in 2014, it has been possible to study in routine clinical care throughout France the effectiveness of a biosimilar rFSH including according to different rFSH starting doses.

METHODS

REOLA was a non-interventional, retrospective, real world study using anonymized data from 17 Assisted Reproductive Technology (ART) centres' data management systems across France including 2,319 ART ovarian stimulation cycles with Bemfola® and 4,287 ART ovarian stimulation cycles with Gonal-f®. For both products, four populations were studied according to starting dose of rFSH: < 150 IU, 150 - 224 IU, 225 - 299 IU and ≥ 300 IU. The primary endpoint was the cumulative live birth rate (cLBR) per commenced ART ovarian stimulation cycle including all subsequent fresh and frozen-thawed embryo transfers starting during a follow up period of at least 1 year following oocyte retrieval.

RESULTS

A direct relationship of increasing rFSH starting dose with increasing age, increasing basal FSH, decreasing AMH and increasing body mass index was noted. No clinically relevant differences were seen in all outcomes reported, including the cLBR, between Bemfola® and Gonal-f®, but for both drugs, an association was seen with increasing rFSH starting dose and decreasing cLBR.

CONCLUSIONS

The REOLA study demonstrates that the cLBR with Bemfola® is very similar to Gonal-f® across all patient subpopulations. The cLBR is inversely related to the rFSH starting dose irrespective of the drug used, and the REOLA study provides reassurance of the clinical effectiveness of a biosimilar rFSH used in a real world setting.

Comparing pregnancy rates following ovarian stimulation with follitropin-Δ to follitropin -α in routine IVF: A retrospective analysis

STUDY OBJECTIVES

Follitropin-Δ, a new recombinant follicle stimulation hormone, uses a fixed daily dose producing a predictable ovarian response while using less gonadotropins compared to follitropin-α. We report clinical outcomes comparing each in the routine IVF setting and further compare qualified to disqualified subjects based on previous randomized controlled trial (RCT) inclusion criteria.

STUDY DESIGN

Retrospective analysis of all cycles performed by a single provider between January 2020 to January 2021. All IVF cycles without patient inclusion-exclusion criteria were considered for the analysis. Clinical outcomes in two groups (follitropin-Δ vs follitropin-α ± 75 IU human menopausal gonadotropin (hMG) in expected poor responders) were compared. In addition, comparisons were made between qualified versus disqualified subgroups.

RESULTS

No differences in baseline demographics, number of MII oocytes, fertilization/MII oocyte, percent of good quality embryos were noted. Compared to those using follitropin-α, follitropin-Δ resulted in lower daily (170 vs 211 IU/d, p = 0.002) and total Gn used (1739 vs 2194 IU, p = 0.003). Optimal range response (8-14 oocytes) (22/44 [50 %] vs 78/203 [38.6 %]; p = 0.10) and fresh (fCP) and cumulative clinical pregnancy (cCP) rates per transfer (29.5 % vs 24.1 % and 35 % vs 25.1 %, p = 0.08) were similar between groups. Based on previous RCTs, those who would have qualified compared to those who would have disqualified, patients using follitropin-Δ were just as likely to have an optimal oocyte response (qualified: 48 % vs disqualified: 57.1 %) and resulted in similar cCP (41.4 % vs 25 %, p-0.23).

CONCLUSIONS

While follitropin-Δ requires less daily and total dosing compared to follitropin-α, optimal range of retrieved oocytes and clinical outcomes appear to be comparable. Using RCT inclusion criteria, similar findings were noted in those who would have qualified compared to disqualified patients.

Pharmacokinetics and Safety of Follitropin Delta in Gonadotropin Down-Regulated Healthy Chinese Women

BACKGROUND

Follitropin delta, a novel recombinant follicle-stimulating hormone (rFSH) preparation derived from a human cell line, has different pharmacokinetic and pharmacodynamic properties compared with existing rFSH preparations expressed by Chinese hamster ovary cells (CHO).

OBJECTIVES

The objective of this study was to assess the pharmacokinetic characteristics, dose proportionality, and safety of follitropin delta in healthy Chinese women.

METHODS

This was a phase I, randomized, open-label study. Twenty-four healthy Chinese women were randomized (1:1:1) to receive a single subcutaneous administration of follitropin delta 12, 18, or 24 μg. The pharmacokinetic parameters (maximum observed serum concentration [C_max], time to reach C_max [t_max], area under the serum concentration-time curve from dosing to infinity [AUC_∞], and elimination phase half-life [t_½]) of follitropin delta were derived using noncompartmental analysis.

RESULTS

Following a single subcutaneous administration of follitropin delta 12, 18, or 24 μg, mean C_max (0.388, 0.677, and 0.825 ng/mL, respectively) and AUC_∞ (41.3, 62.9, and 83.1 h·ng/mL, respectively) increased in a dose-proportional manner. The median t_max was 24 h, and the mean t_½ was in the range of 50.5-60.9 h. All treatment-related adverse events were categorized as mild, except for one case of urticaria from the follitropin delta 18-μg dose group which was considered moderate. Only one woman presented with elevation of alanine transaminase and aspartate aminotransferase at the follow-up visit, which was reported as a treatment-emergent adverse event. There were no injection-site reactions and none of the participants showed any confirmed presence of treatment-induced anti-FSH antibodies.

CONCLUSIONS

The administration of single doses of follitropin delta to healthy Chinese women demonstrated dose-proportional pharmacokinetics over the dose range of 12-24 μg, and these doses were well tolerated.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov registration no. NCT04150861.

Evaluation of correlation between antral follicle diameters with Follicular Output Rate (FORT) in women under controlled ovarian hyperstimulation for assisted reproductive techniques

Background

This study aimed to determine the association of diametrical antral follicles with the ovarian response by Follicular Output Rate (FORT) ratio in 100 females undergoing in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI). This study selected 100 women undergoing controlled ovarian hyperstimulation (COH). The number of antral follicles (diameter of 3–10 mm) was calculated with two-dimensional vaginal sonography on days 1–3 of the cycle. Then, on a triggering day with human chorionic gonadotropin (HCG), the number of follicles (with a diameter of 16–22 mm) and the ratio of FORT were determined. The correlation among FORT with age, antral follicle count (AFC), AFC ≤ 5, AFC > 5, number of preovulatory follicles (16–20 mm), number of metaphase II (MII) oocytes, body mass index (BMI), infertility period, and anti-Mullerian hormone (AMH) was assessed.

Results

There was a significant correlation between FORT and total AFC, AFC > 5, number of preovulatory follicles (16–20 mm), and number of MII oocytes retrieved. There is no significant relationship between FORT and examined two variables (AMH and AFC ≤ 5). Multiple linear regression analysis showed no significant relationship between FORT and examined two variables (AMH and AFC > 5). There was a significant correlation between MII oocytes retrieved and age, total AFC, AFC ≤ 5, AFC > 5, number of preovulatory follicles (16–20 mm), and AMH. A significant positive relationship existed between MII oocytes retrieved and examined two variables (AFC ≤ 5 and AFC > 5).

Conclusion

There was not much difference in the correlation between the AFC ≤ 5 and AFC > 5, and both positively correlated with the number of MII oocytes retrieved.

Clinical Utilities of Anti-Müllerian Hormone

The anti-Müllerian hormone (AMH) plays an essential role in sex determination in early embryonic development. Through a series of sequential steps that follows inheriting an XY chromosome, Sertoli cell differentiation upregulates the expression of AMH-suppressing Müllerian duct development and maintains the AMH at a high level until puberty. In females, the AMH is produced by granulosa cells of follicles beginning in the second half of fetal life and continues through adulthood, with a steady decline through the reproductive years and severe decline at menopause, until levels eventually become undetectable. The AMH is essential for the regulation of follicular maturation via the recruitment of primordial follicles throughout folliculogenesis. AMH serum concentration in women strongly correlates with ovarian reserve quantity and reflects ovulation potential. Because the AMH is expressed almost exclusively by growing follicles before FSH-dependent selection, it commonly serves as a marker for ovarian function in various clinical situations, including in the diagnosis and pathogenesis of polycystic ovarian syndrome, artificial reproductive technology, and predictions of menopause or premature ovarian failure.

Comparative clinical outcome following individualized follitropin delta dosing in Chinese women undergoing ovarian stimulation for in vitro fertilization /intracytoplasmic sperm injection

BACKGROUND

To compare the efficacy and safety of follitropin delta in its individualized fixed-dose regimen with follitropin alfa in a conventional adjustable dosing regimen in Chinese women.  METHODS: This was a subgroup analysis of the randomized, multi-center, assessor-blind, non-inferiority trial (GRAPE) including 759 Chinese women (aged 20-40 years) recruited in 16 reproductive medicine clinics in China. Women were randomized in a 1:1 ratio to be treated with either follitropin delta dose based on anti-Müllerian hormone (AMH) and body weight or conventional dosing with follitropin alfa following a gonadotropin-releasing hormone (GnRH) antagonist protocol. The primary outcome was ongoing pregnancy rate assessed 10-11 weeks after embryo transfer in the fresh cycle (non-inferiority margin -10.0%).

RESULTS

378 in the follitropin delta group and 381 in the follitropin alfa group were randomized and exposed. Non-inferiority was confirmed with respect to ongoing pregnancy with rates of 31.0% vs. 25.7% for follitropin delta compared to follitropin alfa, estimated mean difference of 5.1% (95% confidence interval (CI) -1.3% to 11.5%). The clinical pregnancy rate (35.4% vs. 31.5%, P = 0.239) and live birth rate (31.0% vs. 25.5%, P = 0.101) were comparable between the follitropin delta group and the follitropin alfa group. Overall, the individualized follitropin delta treatment resulted in fewer oocytes retrieved compared to follitropin alfa treatment (10.3 ± 6.2 vs. 12.5 ± 7.5, P < 0.001), which was mainly due to fewer oocytes (10.5 ± 6.4 vs. 13.9 ± 7.8) in women with AMH ≥ 15 pmol/L. Accordingly there was a lower incidence of early ovarian hyper-stimulation syndrome (OHSS) and/or preventive interventions (6.1% vs. 11.0%, P = 0.013). A daily follitropin delta dose of 10.2 µg (95% CI: 9.3-11.2 µg) was estimated to provide the same number of oocytes retrieved as a starting dose of 150 IU/d of follitropin alfa.

CONCLUSION

Follitropin delta in its individualized fixed-dose regimen showed similar efficacy and improved safety compared with follitropin alfa in a conventional adjustable dosing regimen in Chinese women.

CLINICAL TRIAL REGISTRATION NUMBER

NCT03296527.

COVID-19 - compliant - IVF: reorganized clinical practice taking into account the pandemic

PURPOSE

The need for protective measures during the COVID-19 pandemic forced assisted reproduction centers to adopt new protocols in order to reduce the risk of infection for patients and staff. A COVID-19 Compliant IVF (in vitro fertilization) program based on the use of follitropin delta to induce ovarian stimulation and fixed protocol with GnRH (Gonadotropin-Releasing Hormone) antagonists was applied to demonstrate the efficacy of this program in reducing the necessity of patients to be present within the clinic while maintaining the expected success rate.

METHODS

The program was applied to 100 patients (women aged between 20 and 40 years, at their first IVF cycle): pretreatment assessment was carried out via video conference and clinical documentations were sent by email. Ovarian stimulation was based on doses of Follitropin delta selected on the basis of body weight and serum AMH (Anti-Müllerian Hormone). The study population was then compared with historical controls to assess the percentage of patients receiving fresh embryo transfer. Finally, a questionnaire was proposed to assess patient satisfaction.

RESULTS

The ovarian stimulation protocol with a fixed dose of follitropin delta led to an optimal ovarian response (8-14 oocytes) in 54% of the women included in the study. The rate of hyper response was 15% and was significantly lower that what reported in the control group (26.8%, p < .05). The good control of ovarian response to stimulation is the reason for the large percentage of cycles associated with fresh embryo transfer (84%, n 84/100). The rate of fresh embryo transfer was significantly higher that what reported for the control population (68.5%, p < .05). In 40 out of 84 patients, blastocysts were available for the fresh embryo transfer procedure. Eighty-five percent (89/100) of survey responders reported being extremely satisfied with the simplified approach to the IVF cycle because of reduced number of visits, easy management of working hours and reduction in travel costs.

CONCLUSIONS

The use of follitropin delta and fixed protocol with GnRH antagonist in COVID-19 - Compliant IVF program is associated to a low percentage of patients developing excessive ovarian response compared to conventional strategy and a very good level of patient satisfaction. Beyond the pandemic, the new approach to ovarian stimulation, modern technologies and telemedicine could play a key role in bridging the gap between different geographic areas and could offer advantages such as increased accessibility, cost saving and patient satisfaction.

Serum anti-Müllerian hormone as a predictor of polycystic ovarian syndrome among women of reproductive age

BACKGROUND

Polycystic ovarian syndrome (PCOS) affects up to one-fifth of women of reproductive age and causes anovulatory subfertility. Some studies have recommended that an anti-Müllerian hormone (AMH) level greater than 3.8-5 ng/mL can be used for diagnosing PCOS. This study aims to analyse serum AMH levels among PCOS women of reproductive age to use AMH as a biomarker predictor along with other Rotterdam criteria.

METHODS

In this cross-sectional study, a total of 98 women visiting the fertility center of a private hospital in Lahore, Pakistan, were screened. Data were obtained from 51 PCOS newly diagnosed women aged 28.24 years (SD ± 4.84 years) meeting at least two of the Rotterdam criteria and specific inclusion criteria. Baseline variables, menstrual cycle length, ovarian morphology on ultrasound, hirsutism, sex hormones, gonadotropin, and serum AMH levels were analysed during the follicular phase (1-5 days) of the menstrual cycle. Serum AMH was measured by an enzyme-linked immunosorbent assay.

RESULTS

A high serum AMH level (7.23 ± 4.67 ng/ml) was recorded with normal sex hormone levels. Women with oligo-/amenorrhea had a significant mean difference for luteinizing hormone (p = 0.02) and AMH levels (p = 0.03) when compared with women of normal menstrual cycle length. PCOS women with high AMH levels (≥ 3.9 ng/ml) showed a significant difference in ovarian morphology (p < 0.05) when compared with the normal AMH group.

CONCLUSIONS

An elevated serum AMH level can be used as a strong predictor to reflect the certainty of PCOS diagnosis among women of reproductive age when study concurrently with the other Rotterdam criteria.

Algorithm-based individualization methodology of the starting gonadotropin dose in IVF/ICSI and the freeze-all strategy prevent OHSS equally in normal responders: a systematic review and network meta-analysis of the evidence

PURPOSE

Ovarian hyperstimulation syndrome (OHSS) represents a rare but dangerous condition associated with controlled ovarian stimulation (COS) in IVF/ICSI. Over the last decades, many strategies have been introduced into clinical practice with the objective of preventing this potentially life-threatening condition. Among these, the freeze-all policy has gained great popularity, thanks to improvements in vitrification. Nevertheless, not all clinics have adequate skills in vitrification procedures and patients may be dissatisfied with a longer time to pregnancy.

METHODS

This study is a systematic review and network meta-analysis of randomized controlled trials comparing different strategies of ovarian stimulation in IVF/ICSI cycles (freeze-all policy, algorithm-based individualization of the starting dose, experience-based individualization of the starting dose, standard dose) in terms of reduction of OHSS, in normal responders.

RESULTS

The results indicate that only the algorithm-based individualization of the starting gonadotropin dose reduces OHSS similarly to the freeze-all strategy.

CONCLUSION

Albeit in the era of the freeze-all policy, the personalization of the starting gonadotropin dose obtained by the use of algorithms should be pursued as a valid and safe option for IVF.

Extended Injection Intervals of Gonadotropins by Intradermal Administration in IVF Treatment

CONTEXT

Gonadotropins can be administered every 5 days under intradermal injection in in vitro fertilization (IVF) treatment.

OBJECTIVE

To explore the effectiveness of intradermal injection of recombinant human FSH (rhFSH) for women undergoing IVF.

METHODS

Women who received their first IVF treatment enrolled in this prospective intervention in 2018. All women received a bolus of 900 IU rhFSH intradermally at day 2 of the treatment cycle followed by additional dosage of rhFSH at day 7 and/or day 10. The main outcome measures included the total dose of rhFSH and number of injections required, sequential serum FSH level detected, and number of mature oocytes retrieved.

RESULTS

Seventy women completed the study. On average, 2.31 ± 0.73 injections and 1662 ± 397 IU of rhFSH were administered. While the baseline FSH level was 5.6 ± 2.2 IU/L, the serum concentrations of FSH after rhFSH administration were 35.3 ± 7.0 on the first day (24 hours) and 10.7 ± 3.7 IU/L on the fifth day (120 hours). A total of 10.5 ± 6.6 mature oocytes were retrieved, resulting in 7.3 ± 5.1 pronuclear embryos; 1.8 ± 0.6 embryos were transferred to the uterus. Our findings resulted in 72% fertilization, 91% cleavage, 31% implantation, and 36% live birth rates. Although fewer larger follicles were found, noninferiority results were noted in the mature oocytes retrieved, good embryos available, and clinical pregnancy rate compared with those received conventional daily subcutaneous rhFSH administration.

CONCLUSION

Intradermal administration of rhFSH, with a smaller dose of rhFSH and fewer injections, may achieve the goal of a cost-effective and more patient-friendly regimen.

Association Between the Ratio of Ovarian Stimulation Duration to Original Follicular Phase Length and In Vitro Fertilization Outcomes: A Novel Index to Optimise Clinical Trigger Time

The duration of ovarian stimulation which is largely dependent on the ovarian response to hormonal stimulation may influence in vitro fertilization (IVF) outcomes. Menstrual cycle length is potentially a good indicator of ovarian reserve and can predict ovarian response. Ovarian stimulation and the follicular phase of the menstrual cycle are both processes of follicular development. There is no published research to predict the duration of ovarian stimulation based on the length of the menstrual cycle. Our retrospective cohort study included 6110 women with regular menstrual cycles who underwent their first IVF treatment between January 2015 and October 2020. Cycles were classified according to quartiles of the ratio of ovarian stimulation duration to original follicular phase length (OS/FP). Multivariate generalized linear models were applied to assess the association between OS/FP and IVF outcomes. The odds ratio (OR) or relative risk (RR) was estimated for each quartile with the lowest quartile as the comparison group. OS/FP of 0.67 to 0.77 had more retrieved and mature oocytes (adjusted RR 1.11, 95% confidence interval [CI] 1.07-1.15, p for trend = 0.001; adjusted RR 1.14, 95% CI 1.09-1.19, p for trend = 0.001). OS/FP of 0.67 to 0.77 showed the highest rate of fertilization (adjusted OR 1.11, 95% CI 1.05-1.17, p for trend = 0.001). OS/FP > 0.77 had the lowest rate of high-quality blastocyst formation (adjusted OR 0.81, 95% CI 0.71-0.93, p for trend = 0.01). No apparent association was noted between OS/FP and clinical pregnancy, live birth, or early miscarriage rate. In conclusion, OS/FP has a significant effect on the number of oocytes, fertilization rate, and high-quality blastocyst formation rate. MCL could be used to predict the duration of ovarian stimulation with an OS/FP of 0.67 to 0.77, which provides a new indicator for the individualized clinical optimization of the trigger time.

OUP accepted manuscript

STUDY QUESTION

SUMMARY ANSWER

WHAT IS KNOWN ALREADY

STUDY DESIGN, SIZE, DURATION

PARTICIPANTS/MATERIALS, SETTING, METHODS

MAIN RESULTS AND THE ROLE OF CHANCE

LIMITATIONS, REASONS FOR CAUTION

WIDER IMPLICATIONS OF THE FINDINGS

STUDY FUNDING/COMPETING INTEREST(S)

TRIAL REGISTRATION NUMBER

TRIAL REGISTRATION DATE

DATE OF FIRST PATIENT’S ENROLMENT

Prospective multicenter non-interventional real-world study to assess the patterns of use, effectiveness and safety of follitropin delta in routine clinical practice (the PROFILE study)

OBJECTIVE

To observe the real-world utilization patterns, effectiveness and safety profile of follitropin delta in women ≥18 years naïve to ovarian stimulation undergoing in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI).

DESIGN

Prospective, multinational, multicenter, observational study. All IVF/ICSI treatment protocols were conducted according to routine clinical practice, including undertaking fresh/frozen transfers. Outcomes included use of dosing algorithm, follitropin delta dosing patterns, ovarian response, pregnancy rates and adverse drug reactions (ADRs).

RESULTS

The first ovarian stimulation cycle using follitropin delta was initiated in 944 women. Mean baseline demographics were: age, 33.5 ± 4.7 years; bodyweight, 67.1 ± 13.6 kg; anti-Müllerian hormone, 20.3 ± 16.1 pmol/L (2.84 ± 2.25 ng/mL). The dosing algorithm was used to calculate the follitropin delta daily starting dose in 893/944 women (94.5%). The mean difference between the calculated and prescribed daily dose was small (0.2 ± 1.40 µg). The mean daily starting follitropin delta dose was 10.4 ± 2.72 µg and the mean total dose administered was 104 µg. Follitropin delta dose adjustments were reported for 57/944 (6.0%) women. The mean number of retrieved oocytes was 10.1 ± 7.03. Ongoing pregnancy at 10-11 weeks was reported for 255 women (27.0% per initiated cycle and 43.1% per fresh transfer [n=592]). Cumulative ongoing pregnancy rate after fresh and/or frozen transfer was 36.4% (344/944). Four women discontinued follitropin delta due to ADRs. Ovarian hyperstimulation syndrome (OHSS) was the most frequently reported ADR (n=37 [3.9%]); most cases of OHSS were of mild or moderate intensity (n=30 [3.2%]).

CONCLUSIONS

This large real-world study of follitropin delta utilization patterns confirms its good pregnancy rates while minimizing OHSS risk during first ovarian stimulation cycle.