Ovarian Hyperstimulation syndrome combined with hypothyroidism: a comprehensive review.

Ovarian Hyperstimulation Syndrome (OHSS) is a systemic condition marked by the enlargement of the ovaries and heightened vascular permeability. And hypothyroidism (HT) emerges as a potential risk factor for OHSS occurrence. This review presented a comprehensive summary of pertinent case reports involving patients diagnosed with both HT and OHSS. Detailed exploration was conducted into their clinical presentations, diagnostic methodologies, and treatment modalities. Additionally, the review delved into potential interaction mechanisms between HT and OHSS, encompassing various aspects including hormone levels. Moreover, management strategies for mitigating the risk of OHSS in HT patients were thoroughly reviewed and the importance of monitoring thyroid function in those experiencing OHSS was emphasized. This review indicated that the association between HT and OHSS, underscoring its multifaceted complexity. It could accentuate the ongoing necessity for rigorous research and clinical refinement to deepen our comprehension of this association and to bolster diagnostic and therapeutic methodologies for optimal patient care. In conclusion, this review offered valuable insights for future research directions and clinical practices for patients afflicted with OHSS and HT.

Age at menarche and risk of ovarian hyperstimulation syndrome in women undergoing IVF/ICSI cycles: a retrospective cohort study.

OBJECTIVES: We aimed to explore the association between age at menarche (AAM) and ovarian hyperstimulation syndrome (OHSS) in fresh in vitro fertilisation (IVF)/intracytoplasmic sperm injection (ICSI) cycles. DESIGN: A retrospective cohort study. SETTING: Data were collected from a large obstetrics and gynaecology hospital in Sichuan, China. PARTICIPANTS: This study included 17 419 eligible women aged ≤40 years who underwent the first IVF/ICSI cycles from January 2015 to December 2021. Women were divided into three groups according to their AAM: ≤12 years (n=5781), 13-14 years (n=9469) and ≥15 years (n=2169). RESULTS: The means of age at recruitment and AAM were 30.4 years and 13.1 years, respectively. Restricted cubic spline models suggested that early menarche age increased the risk of OHSS. The multivariable logistic analysis showed that women with menarche age ≤12 years were more likely to suffer from OHSS (OR 1.321, 95% CI 1.113 to 1.567) compared with those aged 13-14 years among the whole cohort. This significant relationship remained in women administered with different ovarian stimulation protocols and gonadotrophin doses. When stratified by female age, this correlation was presented only in patients aged ≤30 years (OR 1.362, 95% CI 1.094 to 1.694). And the mediation analysis showed that the relationship between AAM and OHSS was totally mediated by antral follicle counts (AFC). CONCLUSION: Menarche age earlier than 12 years may increase the OHSS risk in women aged ≤30 years through the mediation of AFC. More prospective studies are required to verify the results.

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.

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 ).

Serum erythropoietin level is increased during stimulation for IVF but not in OHSS.

BACKGROUND: Erythropoietin (Epo) is a potent vascular growth factor that induces angiogenesis and antiapoptotic signalling. We investigated whether the development of numerous follicles and corpora lutea during in vitro fertilization (IVF) cycle affects circulating Epo levels and further, if Epo could be used as a novel marker for ovarian hyperstimulation syndrome (OHSS). METHODS: 24 women were included in the uncomplicated IVF group and 35 women in the OHSS group. Repeated blood samples from both groups were analysed for Epo, progesterone, blood haemoglobin, and creatinine. Follicular fluid from the IVF group was analysed for Epo and progesterone. Repeated measure analysis was performed for the variables and circulating Epo levels were compared between the IVF group and early OHSS. Furthermore, related growth factors, vascular endothelial growth factor (VEGF) and hypoxia-inducible factor-1 (HIF-1) were analysed from subgroup of women to test for correlation with Epo. RESULTS: During IVF, circulating Epo increased from natural mid-luteal phase to stimulated mid-luteal phase (median 9.5; 95% CI 7.2-13.4 IU/L and 12.5; 10.3-13.4 IU/L; p = 0.003). In cycles resulting in pregnancy, Epo level decreased 14 days after oocyte pick-up (OPU) and remained low thereafter. In cycles not resulting in pregnancy, Epo level increased again 35 days after OPU. Follicle fluid Epo concentration was 1.5 times higher than the serum concentration (median 15.4; 95% CI 10.4-19.2 IU/L vs. 10.2; 8.8-12.7; p = 0.006). There was no difference in circulating Epo concentration between early OHSS and uncomplicated IVF. Circulating Epo did not correlate with VEGF or HIF-1. CONCLUSIONS: Circulating Epo levels fluctuate during IVF cycle. We hypothesise this may suggest Epo's involvement in ovarian physiology and angiogenesis. However, Epo was not a clinical marker for OHSS.

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.

In vitro maturation (IVM) of human immature oocytes: is it still relevant?

In vitro maturation (IVM) of human immature oocytes has been shown to be a viable option for patients at risk of ovarian hyperstimulation syndrome (OHSS), those seeking urgent fertility preservation and in circumstances where controlled ovarian stimulation is not feasible. Moreover, IVM techniques can be combined with ovarian tissue cryobanking to increase the chances of conception in cancer survivors. The clinical applications of IVM in the field of reproductive medicine are rapidly expanding and the technique is now classified as non-experimental. In contrast to conventional IVF (in vitro fertilization), IVM offers several advantages, such as reduced gonadotropin stimulation, minimal risk of ovarian hyperstimulation syndrome (OHSS), reduced treatment times and lower costs. However, the technical expertise involved in performing IVM and its lower success rates compared to traditional IVF cycles, still pose significant challenges. Despite recent advances, such as innovative biphasic IVM systems, IVM is still an evolving technique and research is ongoing to refine protocols and identify techniques to improve its efficiency and effectiveness. A comprehensive understanding of the distinct mechanisms of oocyte maturation is crucial for obtaining more viable oocytes through in vitro methods, which will in turn lead to significantly improved success rates. In this review, the present state of human IVM programs and future research directions will be discussed, aiming to promote a better understanding of IVM and identify potential strategies to improve the overall efficiency and success rates of IVM programs, which will in turn lead to better clinical outcomes.

Analysis of controlled ovarian hyperstimulation protocols in women over 35 years old with poor ovarian response: a real-world study.

The objective of this study was to investigate the optimal controlled ovarian hyperstimulation (COH) protocol for patients aged 35 and above with poor ovarian response (POR), utilizing real-world data. This retrospective cohort study examined clinical information from a total of 4256 patients between January 2017 and November 2022. The patients were categorized into three groups: modified GnRH agonist protocol (2116 patients), GnRH antagonist protocol (1628 patients), and Mild stimulation protocol (512 patients). Comparative analysis was conducted on clinical variables and pregnancy outcomes across the three groups. The GnRH agonist protocol was associated with a higher number of oocyte number (4.02 ± 2.25 vs. 3.15 ± 1.52 vs. 2.40 ± 1.26, p < 0.001), higher number of transferable embryos (1.73 ± 1.02 vs. 1.35 ± 1.22 vs. 1.10 ± 0.86, p = 0.016), higher cumulative live birth rate 28.50(603/2116) vs. 24.94(406/1628) vs. 20.51(105/512), p < 0.001) than GnRH antagonist protocol and Mild stimulation protocol, the Mild stimulation protocol was associated with a higher miscarriage rates 16.27(62/381) vs. 16.61(48/289) vs. 32.22(29/90), p = 0.001) than the other two groups. Therefore, it can be concluded that all three protocols can be used in patients over 35 years old with poor ovarian response. However, if patients require more frozen-thawed embryo transfers to achieve better cumulative live birth rates, the modified GnRH agonist protocol may be the preferable option.

Normal and Abnormal Appearances of the Ovaries during Assisted Reproduction: Multimodality Imaging Review.

Infertility is a common diagnosis that prompts many couples and individuals to seek assisted reproductive technology (ART) for assistance with conception. These technologies have become increasingly used in the United States in the past several decades, with 326 468 ART cycles performed in 2020, resulting in 75 023 live births. This ubiquity of ART also increases the likelihood that radiologists will encounter both normal and abnormal imaging findings associated with these treatments. Thus, radiologists of all subspecialties should be familiar with the multimodality appearance of the ovaries and pelvis in patients undergoing ART treatments. Furthermore, it is imperative that radiologists understand the appearance expected during different stages of the ART process. During stimulated ovulatory cycles, it is normal and expected for the ovaries to appear enlarged and to contain numerous cystic follicles, often with a small to moderate volume of pelvic free fluid. After oocyte retrieval, hemorrhagic ovarian follicles and a small to moderate volume of blood products in the cul-de-sac can be expected to be seen. Multiple nonemergency and emergency complications are related to ART, many of which can be seen at imaging. The most encountered emergency complications of ART include ovarian hyperstimulation syndrome, ectopic pregnancy, heterotopic pregnancy, multiple gestations, ovarian torsion, and procedural complications related to oocyte retrieval. These complications have important clinical implications, thus necessitating accurate and timely detection by the radiologist and the clinical team. ©RSNA, 2023 Supplemental material is available for this article. Quiz questions for this article are available through the Online Learning Center.

Clinical characteristics of functioning gonadotroph adenoma in women presenting with ovarian hyperstimulation: Audit of UK pituitary centres.

OBJECTIVE: Functioning gonadotroph adenomas (FGAs) are rare pituitary tumours stimulating ovarian function with potential life-threatening consequences in women. However, a lack of aggregated clinical experience of FGAs impairs management in affected women. The aim of this study is to present the clinical course of FGA-induced ovarian hyperstimulation syndrome (OHSS) cases as identified by some of the largest UK pituitary endocrine tertiary centres with a view to increasing awareness and improving diagnosis and management of women with FGA. DESIGN: A retrospective observational study; audit of eight UK regional pituitary centres for cases of FGAs. SETTING: Specialist neuroendocrine centres in the United Kingdom. PATIENTS AND MEASUREMENTS: Women diagnosed with FGA-induced OHSS. Description of their clinical course. RESULTS: Seven cases of FGA were identified in women, all causing OHSS. Mean age was 33.4 years at diagnosis. Abdominal pain, irregular periods, headache, and visual disturbances were reported at presentation by 100%, 71%, 57% and 43% of women, respectively. Three of seven women underwent ovarian surgery before FGA diagnosis. Six women underwent transsphenoidal surgery (TSS) with incomplete tumour resection in five of those, but all showed improvement or resolution in symptoms and biochemistry postoperatively. CONCLUSION: FGA is a rare cause of spontaneous OHSS. TSS improves clinical and biochemical features of ovarian hyperstimulation in FGAs. Improved awareness of FGA will prevent inappropriate emergency ovarian surgery.

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.

The ovarian hyperstimulation that truly matters: Admissions, severity and prevention strategies.

INTRODUCTION: Ovarian hyperstimulation syndrome (OHSS) is a common but serious complication of in vitro fertilisation. Despite available strategies to reduce OHSS incidence, a small proportion of patients will develop the clinically significant disease with substantial morbidity. Efforts toward better understanding and the prevention of severe disease are required to improve patient outcomes. AIMS: The aims are to: (1) formulate clinically relevant OHSS classification for inpatient settings and data collection/reporting; (2) estimate OHSS prevalence requiring hospital admission in Victoria; and (3) determine the extent of OHSS preventability with clinical strategies. MATERIALS AND METHODS: This retrospective cohort study included all OHSS admissions in a tertiary referral centre, January 2016-December 2021, which included approximately 40% of all cases of hospitalisation for OHSS in the State of Victoria. Patient characteristics, treatment regimes, fertility treatment outcomes, timing classification, and clinical markers of disease severity were studied. Patients were classified as having mild, moderate, or severe OHSS with a novel inpatient classification system. RESULTS: Of 199 OHSS cases presenting to the tertiary institution, 107 were classified as moderate/severe, with no significant difference between age, body mass index, length of stimulation and follicle number between mild/moderate and severe groups. There were more cases of early hyperstimulation (137) compared to late (62) presentation, of which 53% were severe. The average length of stay overall was 3.1 days, and 5.2 days for severe presentations. In 15% of severe cases, an agonist trigger was used. CONCLUSIONS: The overall prevalence of OHSS requiring hospital admission appears to be low (approximately 0.6% of all stimulated cycles). Established risk factors may not accurately predict clinically relevant OHSS risk. Further monitoring, clinician and patient education are required to minimise the risk of significant OHSS that results in hospital admissions.

Managing ovarian hyperstimulation syndrome: A qualitative interview study with women and healthcare professionals.

AIM: To explore the experiences of women who have had ovarian hyperstimulation syndrome, and healthcare professionals who care for them. BACKGROUND: Ovarian hyperstimulation syndrome is a side effect of fertility treatment. Little research exists internationally that explores the experiences of women who have had this condition, or the healthcare professionals who manage it. DESIGN: Qualitative study using semi-structured interviews. METHODS: Eighteen interviews with women who had experienced ovarian hyperstimulation syndrome (n = 10) and healthcare professionals (n = 8) in six UK fertility centres. Framework analysis was used. This paper is reported following COREQ guidelines. RESULTS: Women described a range of symptoms and severity, sometimes experiencing worrying physical health problems such as abdominal swelling and shortness of breath. The combination of the symptoms, and their management, on delaying future fertility treatment could cause emotional distress. Healthcare professionals at different centres described variation in practice, which generally involved 'active monitoring' until symptoms became severe, when women would be hospitalised. Women expressed feeling 'left in limbo' while waiting for symptoms to improve or worsen, and described a lack of control during this waiting period. Healthcare professionals felt they provided adequate information about ovarian hyperstimulation syndrome and its management. This, however, did not align with women's perceptions that information, including potential delays to their fertility treatment, was missing. There was similar mismatch between women's and healthcare professionals' views of decision-making about fertility treatment following ovarian hyperstimulation syndrome, including women's concerns about having to make rushed, unplanned decisions about their fertility treatment when they did not feel adequately informed to do so. CONCLUSION: Ovarian hyperstimulation syndrome and its management can have a significant physical and emotional impact on women, and influence their fertility treatment. Improvements could be made to the information women receive about this condition, its management and its implications for wider fertility treatment. IMPLICATIONS FOR THE PROFESSION AND/OR PATIENT CARE: Nurses have the skills and knowledge to support women through the physical and emotional stresses of fertility treatment. Therefore, they are well placed to provide specialist information and support for OHSS and ensure women are fully informed about all aspects of the condition, including how its management might delay fertility treatment.

Prothrombotic biomarkers during controlled ovarian stimulation for assisted reproductive technology.

OBJECTIVE: To assess the impact of 3 different ovarian stimulation protocols on surrogate biomarkers of coagulation. DESIGN: Observational multicenter cohort study. SETTING: The study was conducted in assisted reproductive technology (ART) units. PATIENTS: Infertile women undergoing ART in 2017-2019 were included. INTERVENTIONS: None. MAIN OUTCOME MEASURE(S): Our primary outcome was the endogenous thrombin potential (ETP) assessed by the calibrated automated thrombogram. The ETP was measured at baseline (T1), on the day of ovulation triggering (T2), and 7 days after triggering (T3). Three protocols were prescribed according to the standards used and without hormonal before treatment: agonist protocol with human chorionic gonadotropin (hCG) trigger (ag-hCG), antagonist protocol with hCG trigger (atg-hCG), or GnRH agonist trigger. The evolution of ETP was compared among groups using a mixed-effects linear regression model. RESULT(S): Sixty-four women with a mean age of 37.8 years participated in the study: of which 24, 16, 24 received ag-hCG, atg-hCG, and GnRH agonist triggers, respectively. As expected, the mean serum estradiol levels in GnRH agonist trigger were statistically higher at T2 and lower at T3 than that for both ag-hCG and atg-hCG. Overall, the ETP evolution over time was statistically different between the groups. Values were similar between groups at T1 and increased at T2 in each group. The greatest difference occurred between T2 and T3 in each group. The ETP continued to increase at T3 in ag-hCG (+110 nM/L × min) and atg-hCG (+171 nM/L × min), but it remained stable in GnRH agonist trigger (-2 nM/L × min). Sex hormone-binding globulin showed persistent increase at T3 despite the fall in estradiol levels, particularly in the GnRH agonist trigger group. CONCLUSION(S): The ag-hCG and atg-hCG groups were associated with a higher hypercoagulable state at T3 than the GnRH agonist trigger group. However, our results show the persistence of a hypercoagulable state after the GnRH agonist triggering despite a sharp drop in estradiol levels. These findings may support the use of GnRH agonist trigger protocol in patients with high thrombotic risk and gives new insight into the fact that coagulation parameters could be disturbed for long time periods. CLINICAL TRIAL REGISTRATION NUMBER: NCT04188444.

Cryopreservation as a strategy for prevention of ovarian hyperstimulation syndrome in a public assisted reproduction service in São Paulo - Brazil.

OBJECTIVE: This study aimed to evaluate the prevalence of ovarian hyperstimulation syndrome (OHSS) and associated risk factors in patients undergoing fertilization cycles at risk of OHSS (≥15 antral follicles or ≥15 oocytes aspirated) and submitted to cryopreservation of all embryos in the Human Reproduction Service of the Pérola Byington Hospital (Referral Center for Women's Health) in São Paulo, SP, Brazil. METHODS: This cross-sectional, institutional, descriptive study of secondary data from patients' charts enrolled in the Assisted Reproduction Service of the Pérola Byington Hospital at risk of OHSS after controlled ovarian stimulation and submitted to cryopreservation of all embryos was conducted between January 2015 and September 2017. RESULTS: OHSS occurred in 47.5% of cycles, all with mild severity, and there were no moderate or severe cases of OHSS. CONCLUSION: The cryopreservation of all embryos is associated with a reduction in moderate and severe forms of OHSS. Risk factors for OHSS should be evaluated prior to initiation of treatment, with less intense stimulation protocols accordingly.

Venous Thromboembolism Associated with Assisted Reproductive Technology: A Systematic Review and Meta-analysis.

BACKGROUND: Hormonal exposure leads to an increased risk of venous thromboembolism (VTE) but the risk of VTE associated with assisted reproductive technology (ART) is not clearly determined. METHODS: We searched in PubMed, EMBASE, Web of Science, and the Cochrane Library databases and identified all relevant articles published up to February 1, 2021. The primary objective was to determine the frequency of VTE associated with ART. Secondary objectives were to determine (1) the risk of VTE associated with ART as compared to pregnancy without ART; (2) the risk of VTE associated with ovarian hyperstimulation syndrome (OHSS); and (3) to determine potential risk factors of VTE related to ART. RESULTS: Fourteen studies were included. The overall frequency of VTE associated with ART was 0.23% (95% confidence interval [CI]: 0.07-0.46). Women undergoing ART had a two- to threefold increased risk of VTE as compared to spontaneous pregnancy (relative risk [RR]: 2.66; 95% CI: 1.60-4.43). The overall frequency of VTE specifically related to OHSS was <0.001%. The risk of VTE after ART complicated by OHSS, as compared to ART without OHSS, was higher but not statistically significant (RR: 14.83; 95% CI: 0.86-255.62). Risk factors of VTE associated with ART were in vitro fertilization procedure (RR, odds ratio [OR], and hazard ratio varying from 1.77, 95% CI: 1.41-2.23 to 4.99, 95% CI: 1.24-20.05), hyperhomocysteinemia (OR: 15.2; 95% CI: 2.0-115.0), polycystic ovarian syndrome (PCOS) (RR: 4.8; 95% CI: 1.7-13.4), successful ART leading to pregnancy (OR: 13.94; 95% CI: 1.41-137.45). CONCLUSION: Further large prospective studies on risk factors of VTE in women undergoing ART are needed in order to optimize thromboprophylaxis in this context.

IVF/ICSI Outcomes After a Freeze-All Strategy: an Observational Cohort Study.

In order to inform patients undergoing ART regarding their chances for motherhood, it seems useful to describe "freeze all" outcomes according to the different potential indications. The goal of this study was to examine the impact of a "freeze-all approach" on the cumulative live birth rate (cLBR) according to the indication. It is a cohort study including women who had undergone ovarian stimulation (OS) using an antagonist protocol with GnRH agonist triggering between 09.2016 and 09.2018 followed by a freeze-all cycle of blastocyst embryos. The ART outcomes were compared between the two main indications of the freeze-all strategy which were in our cohort: risk of ovarian hyperstimulation syndrome (OHSS) and endometriosis. The ART outcomes were also described for the others indications (inadequate endometrium and/or premature progesterone elevation at trigger day, two or more previous ART failures, and autoimmune disease and/or a high risk of thromboembolic disease (AI and/or TE risk)). In total, 658 women were included. The cLBR in the total population was 37.7% (248/658). The cLBR was significantly higher in the "OHSS risk" group (133/281, 47.3%) than in the "endometriosis" group (69/190, 36.3%) (p = 0.017). No significant differences were noted regarding perinatal outcomes, except a significantly higher risk of placenta praevia (PP) observed in the "endometriosis" group (10.1%) (p = 0.002). The "freeze-all approach" yielded good results in terms of the cLBR and especially in case of OHSS risk. These data should be taken into account when informing patients about the ART strategy and their chances of motherhood.