Embryo freezing for preventing ovarian hyperstimulation syndrome

Dopamine agonists for preventing ovarian hyperstimulation syndrome

BACKGROUND

Ovarian hyperstimulation syndrome (OHSS) is a potentially serious complication of ovarian stimulation in assisted reproduction technology (ART). It is characterised by enlarged ovaries and an acute fluid shift from the intravascular space to the third space, resulting in bloating, increased risk of venous thromboembolism, and decreased organ perfusion. Most cases are mild, but forms of moderate or severe OHSS appear in 3% to 8% of in vitro fertilisation (IVF) cycles. Dopamine agonists were introduced as a secondary prevention intervention for OHSS in women at high risk of OHSS undergoing ART treatment.  OBJECTIVES: To assess the effectiveness and safety of dopamine agonists in preventing OHSS in women at high risk of developing OHSS when undergoing ART treatment.

SEARCH METHODS

We searched the following databases from inception to 4 May 2020: Cochrane Gynaecology and Fertility Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL, and PsycINFO for randomised controlled trials (RCTs) assessing the effect of dopamine agonists on OHSS rates. We also handsearched reference lists and grey literature.

SELECTION CRITERIA

We considered RCTs for inclusion that compared dopamine agonists with placebo/no intervention or another intervention for preventing OHSS in ART. Primary outcome measures were incidence of moderate or severe OHSS and live birth rate. Secondary outcomes were rates of clinical pregnancy, multiple pregnancy, miscarriage, and adverse events.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles, abstracts, and full texts of publications; selected studies; extracted data; and assessed risk of bias. We resolved disagreements  by consensus. We reported pooled results as odds ratios (OR) and 95% confidence interval (CI) by the Mantel-Haenszel method. We applied GRADE criteria to judge overall quality of the evidence.

MAIN RESULTS

The search identified six new RCTs, resulting in 22 included RCTs involving 3171 women at high risk of OHSS for this updated review. The dopamine agonists were cabergoline, quinagolide, and bromocriptine. Dopamine agonists versus placebo or no intervention Dopamine agonists probably lowered the risk of moderate or severe OHSS compared to placebo/no intervention (OR 0.32, 95% CI 0.23 to 0.44; 10 studies, 1202 participants; moderate-quality evidence). This suggests that if the risk of moderate or severe OHSS following placebo/no intervention is assumed to be 27%, the risk following dopamine agonists would be between 8% and 14%. We are uncertain of the effect of dopamine agonists on rates of live birth (OR 0.96, 95% CI 0.60 to 1.55; 3 studies, 362 participants; low-quality evidence). We are also uncertain of the effect of dopamine agonists on clinical pregnancy, multiple pregnancy, miscarriage  or adverse events (very low to low-quality evidence). Dopamine agonists plus co-intervention versus co-intervention Dopamine agonist plus co-intervention (hydroxyethyl starch, human albumin, or withholding ovarian stimulation 'coasting') may decrease the risk of moderate or severe OHSS compared to co-intervention (OR 0.48, 95% CI 0.28 to 0.84; 4 studies, 748 participants; low-quality evidence). Dopamine agonists may improve rates of live birth (OR 1.21, 95% CI 0.81 to 1.80; 2 studies, 400 participants; low-quality evidence). Dopamine agonists may improve rates of clinical pregnancy and miscarriage, but we are uncertain if they improve rates of multiple pregnancy  or adverse events (very low to low-quality evidence). Dopamine agonists versus other active interventions We are uncertain if cabergoline improves the risk of moderate or severe OHSS compared to human albumin (OR 0.21, 95% CI 0.12 to 0.38; 3 studies, 296 participants; very low-quality evidence), prednisolone (OR 0.27, 95% CI 0.05 to 1.33; 1 study; 150 participants; very low-quality evidence), hydroxyethyl starch (OR 2.69, 95% CI 0.48 to 15.10; 1 study, 61 participants; very low-quality evidence), coasting (OR 0.42, 95% CI 0.18 to 0.95; 3 studies, 320 participants; very low-quality evidence), calcium infusion (OR 1.83, 95% CI 0.88 to 3.81; I² = 81%; 2 studies, 400 participants; very low-quality evidence), or diosmin (OR 2.85, 95% CI 1.35 to 6.00; 1 study, 200 participants; very low-quality evidence). We are uncertain of the effect of dopamine agonists on rates of live birth (OR 1.08, 95% CI 0.73 to 1.59; 2 studies, 430 participants; low-quality evidence). We are uncertain of the effect of dopamine agonists on clinical pregnancy, multiple pregnancy or miscarriage (low to moderate-quality evidence). There were no adverse events reported.

AUTHORS' CONCLUSIONS

Dopamine agonists probably reduce the incidence of moderate or severe OHSS compared to placebo/no intervention, while we are uncertain of the effect on adverse events and pregnancy outcomes (live birth, clinical pregnancy, miscarriage). Dopamine agonists plus co-intervention may decrease moderate or severe OHSS rates compared to co-intervention only, but we are uncertain whether dopamine agonists affect pregnancy outcomes. When compared to other active interventions, we are uncertain of the effects of dopamine agonists on moderate or severe OHSS and pregnancy outcomes.

Ovarian hyperstimulation syndrome after assisted reproductive technologies: trends, predictors, and pregnancy outcomes

OBJECTIVES

To assess trends, predictors, and perinatal outcomes of ovarian hyperstimulation syndrome (OHSS) associated with in vitro fertilization (IVF) cycles in the United States.

DESIGN

Retrospective cohort study using National Assisted Reproductive Technology Surveillance System (NASS) data.

SETTING

Not applicable.

PATIENT(S)

Fresh autologous and embryo-banking cycles performed from 2000 to 2015.

INTERVENTIONS(S)

None.

MAIN OUTCOME MEASURE(S)

OHSS, first-trimester loss, second-trimester loss, stillbirth, low birth weight, and preterm delivery.

RESULT(S)

The proportion of IVF cycles complicated by OHSS increased from 10.0 to 14.3 cases per 1,000 from 2000 to 2006, and decreased to 5.3 per 1,000 from 2006 to 2015. The risk of OHSS was highest for cycles with more than 30 oocytes retrieved (adjusted risk ratio [aRR] 3.85). OHSS was associated with a diagnosis of ovulatory disorder (aRR 2.61), tubal factor (aRR 1.14), uterine factor (aRR 1.17) and cycles resulting in pregnancy (aRR 3.12). In singleton pregnancies, OHSS was associated with increased risk of low birth weight (aRR 1.29) and preterm delivery (aRR 1.32). In twin pregnancies, OHSS was associated with an increased risk of second-trimester loss (aRR 1.81), low birth weight (aRR 1.06), and preterm delivery (aRR 1.16).

CONCLUSION(S)

Modifiable predictive factors for OHSS include number of oocytes retrieved, pregnancy following fresh embryo transfer, and the type of medication used for pituitary suppression during controlled ovarian hyperstimulation. Patients affected by OHSS had a higher risk of preterm delivery and low birth weight. Clinicians should take measures to reduce the risk of OHSS whenever possible.

Assisted reproductive technology: an overview of Cochrane Reviews

BACKGROUND

As many as one in six couples will encounter problems with fertility, defined as failure to achieve a clinical pregnancy after regular intercourse for 12 months. Increasingly, couples are turning to assisted reproductive technology (ART) for help with conceiving and ultimately giving birth to a healthy live baby of their own. Fertility treatments are complex, and each ART cycle consists of several steps. If one of these steps is incorrectly applied, the stakes are high as conception may not occur. With this in mind, it is important that each step of the ART cycle is supported by good evidence from well-designed studies.

OBJECTIVES

To summarise the evidence from Cochrane systematic reviews on procedures and treatment options available to couples with subfertility undergoing assisted reproductive technology (ART) procedures.

METHODS

Published Cochrane systematic reviews of couples undergoing ART procedures (in vitro fertilisation or intracytoplasmic sperm injection) were eligible for inclusion in the overview. We also identified Cochrane reviews in preparation, for future inclusion.The primary outcome of the overview was live birth or the composite outcome live birth or ongoing pregnancy, as reported by the included reviews. Our secondary outcomes were clinical pregnancy, multiple pregnancy, miscarriage, and ovarian hyperstimulation syndrome. We excluded studies of intrauterine insemination and ovulation induction.We undertook selection of systematic reviews, data extraction, and quality assessment in duplicate. We assessed review quality by using the AMSTAR tool. We organised reviews by their relevance to specific stages in the ART cycle. We summarised their findings in the text and reported data for each outcome in 'Additional tables'.

MAIN RESULTS

We included 68 systematic reviews published in the Cochrane Library up to May 2018. All were of high quality. These reviews identified 38 interventions that were effective (n = 23) or promising (n = 15), and they identified 19 interventions that were ineffective (n = 2) or possibly ineffective (n = 17). For 15 interventions, review authors were unable to draw conclusions owing to lack of evidence.We identified an additional 11 protocols and four titles for future inclusion in this overview.

AUTHORS' CONCLUSIONS

This overview provides the most up-to-date evidence on ART cycles from systematic reviews of randomised controlled trials. Fertility treatments are costly, and the stakes are high. Using the best available evidence to optimise outcomes is best practice. Evidence from this overview could be used to develop clinical practice guidelines and protocols that can be applied in daily clinical practice to improve live birth rates and reduce rates of multiple pregnancy, cycle cancellation, and ovarian hyperstimulation syndrome.

Ovarian Hyperstimulation Syndrome: A Narrative Review of Its Pathophysiology, Risk Factors, Prevention, Classification, and Management

Ovarian hyperstimulation syndrome (OHSS) is a serious complication of ovulation induction that usually occurs after gonadotropin stimulation, followed by human chorionic gonadotropin administration, for infertility treatment. The existing knowledge about the pathophysiology, risk factors, and primary and secondary methods for the prevention of OHSS is reviewed in this manuscript. The clinical manifestations and characteristics of mild, moderate, severe, and critical forms of the syndrome are defined. The methods of handling affected cases as outpatient or in-hospital management methods as well as indications for hospitalization are summarized in this review. The clinical and biochemical routes of assessing and monitoring hospitalized patients with OHSS, various drugs and medical treatment strategies including indications for aspiration of the ascitic fluid and pleural effusion, and also rare indications for surgery are briefly explained in this article. Severe OHSS, which two decades ago was considered an iatrogenic life-threatening condition, can now be effectively prevented or managed during the early stages. An OHSS-free clinic can be established nowadays by carefully considering the endocrinology of ovulation and using appropriate and dose-adjusted pharmaceutical agents, which are summarized and discussed in this review.

[Birth weight and frozen embryo transfer: State of the art]

The aim of this study was to update our acknowledgment if there is a link between assisted embryo cryopreservation and epigenetics in human? Animal studies have demonstrated epigenetics consequence and especially imprinting disorders due to in vitro culture. In human, it is important to note that after frozen embryo transfer birth weight is significantly increased by 81 to 250g. But these studies cannot identify the reasons of such difference. This review strongly suggests that embryo cryopreservation is responsible for birth weight variations but mechanisms not yet elucidated. Epigenetics is probably one of these but to date, none study is able to prove it. We have to be attentive on a possible link between assisted reproductive technology (ART) and epigenetics reprogrammation.

A novel oocyte maturation trigger using 1500 IU of human chorionic gonadotropin plus 450 IU of follicle-stimulating hormone may decrease ovarian hyperstimulation syndrome across all in vitro fertilization stimulation protocols

PURPOSE

Modification of the trigger used to induce final oocyte maturation in in vitro fertilization (IVF) is a major strategy used to reduce the risk of ovarian hyperstimulation syndrome (OHSS). A novel trigger composed of 1500 IU of human chorionic gonadotropin (hCG) plus 450 IU of follicle-stimulating hormone (FSH) has been developed to reduce OHSS risk. This study compares outcomes of the novel trigger to conventional triggers used in high-risk OHSS patients undergoing IVF.

METHODS

In this retrospective cohort study, IVF cycles at high risk for OHSS based on a serum estradiol > 5000 pg/ml on trigger day conducted between January 2008 and February 2016 were evaluated. Oocyte maturation was induced with the novel trigger (1500 IU hCG plus 450 IU FSH) or a conventional trigger [3300 IU hCG, gonadotropin-releasing hormone agonist (GnRHa) alone, or GnRHa plus 1500 IU hCG]. IVF cycle outcomes were compared. Trigger strategies were examined for associations with OHSS development using logistic regression.

RESULTS

Among 298 eligible IVF cycles identified, there were no differences in oocyte maturation, fertilization, embryo quality, or pregnancy outcomes among all triggers. After adjusting for serum estradiol level and number of follicles, the novel trigger was associated with lower odds of OHSS symptom development compared to the 3300 IU hCG and GnRHa plus hCG 1500 IU triggers (p = 0.007 and 0.04, respectively).

CONCLUSIONS

This study suggests that 1500 IU hCG plus 450 IU FSH may be associated with decreased OHSS symptoms compared to conventional triggers, while producing similar IVF and pregnancy outcomes. More important, this novel trigger may provide a superior alternative in down-regulated cycles and in patients with hypothalamic dysfunction where GnRHa triggers cannot be utilized.

Management of ovarian stimulation for IVF: narrative review of evidence provided for World Health Organization guidance

In this paper, a review of evidence provided to the World Health Organization (WHO) guideline development, who prepare global guidance on the management of ovarian stimulation for women undergoing IVF, is presented. The purpose of ovarian stimulation is to facilitate retrieval of multiple oocytes during a single IVF cycle. Availability of multiple oocytes compensates for inefficiencies in subsequent stages of the cycle, which include oocyte maturation, IVF, embryo culture, embryo transfer, and implantation. Multiple embryos can be transferred in most women, and spare embryos can be frozen to allow for future chances of pregnancy without the need for repeated ovarian stimulation and oocyte retrieval. Our evidence synthesis team addressed 10 clinical questions on management of ovarian stimulation for IVF, prepared a narrative review of the evidence and drafted recommendations to be considered through WHO guideline development processes. Our main outcome measures were live birth, clinical pregnancy, and ovarian hyperstimulation syndrome.

The high responder: a review of pathophysiology and outcomes during IVF treatment

This review attempts to summarize the known literature on high responders to ovarian stimulation during assisted reproductive techniques (ART). Response to gonadotrophins is subject to significant interindividual and intercycle variation, thus carrying a risk of high response or poor response to ovarian stimulation regimens. The main risk for high responders is the development of ovarian hyperstimulation syndrome (OHSS) which is associated with significant morbidity. Hence, the definition of high responders in the literature has primarily focussed on risk factors for OHSS. Strategies to reduce OHSS including tailoring of the ovarian stimulation regimens and adjusting gonadotrophin doses according to patient characteristics and findings during the cycle of stimulation. In addition, modifying the type of ovulation trigger used and adjuvant therapies, such as metformin, intravenous colloids and vascular endothelial growth factor blockers, have also been studied as options to reduce OHSS. Apart from the risk of OHSS, high response also appears to have an adverse impact on the oocyte and endometrium, though there is a paucity of data regarding the extent and mechanisms behind this impact.

Interventions for the prevention of OHSS in ART cycles: an overview of Cochrane reviews

BACKGROUND

Ovarian hyperstimulation syndrome (OHSS) in assisted reproductive technology (ART) cycles is a treatment-induced disease that has an estimated prevalence of 20% to 33% in its mild form and 3% to 8% in its moderate or severe form. These numbers might even be higher for high-risk women such as those with polycystic ovaries or a high oocyte yield from ovum pickup.

OBJECTIVES

The objective of this overview is to identify and summarise all evidence from Cochrane systematic reviews on interventions for prevention or treatment of moderate, severe and overall OHSS in couples with subfertility who are undergoing ART cycles.

METHODS

Published Cochrane systematic reviews reporting on moderate, severe or overall OHSS as an outcome in ART cycles were eligible for inclusion in this overview. We also identified Cochrane submitted protocols and title registrations for future inclusion in the overview. The evidence is current to 12 December 2016. We identified reviews, protocols and titles by searching the Cochrane Gynaecology and Fertility Group Database of Systematic Reviews and Archie (the Cochrane information management system) in July 2016 on the effectiveness of interventions for outcomes of moderate, severe and overall OHSS. We undertook in duplicate selection of systematic reviews, data extraction and quality assessment. We used the AMSTAR (Assessing the Methodological Quality of Systematic Reviews) tool to assess the quality of included reviews, and we used GRADE methods to assess the quality of the evidence for each outcome. We summarised the characteristics of included reviews in the text and in additional tables.

MAIN RESULTS

We included a total of 27 reviews in this overview. The reviews were generally of high quality according to AMSTAR ratings, and included studies provided evidence that ranged from very low to high in quality. Ten reviews had not been updated in the past three years. Seven reviews described interventions that provided a beneficial effect in reducing OHSS rates, and we categorised one additional review as 'promising'. Of the effective interventions, all except one had no detrimental effect on pregnancy outcomes. Evidence of at least moderate quality indicates that clinicians should consider the following interventions in ART cycles to reduce OHSS rates.• Metformin treatment before and during an ART cycle for women with PCOS (moderate-quality evidence).• Gonadotrophin-releasing hormone (GnRH) antagonist protocol in ART cycles (moderate-quality evidence).• GnRH agonist (GnRHa) trigger in donor oocyte or 'freeze-all' programmes (moderate-quality evidence). Evidence of low or very low quality suggests that clinicians should consider the following interventions in ART cycles to reduce OHSS rates.• Clomiphene citrate for controlled ovarian stimulation in ART cycles (low-quality evidence).• Cabergoline around the time of human chorionic gonadotrophin (hCG) administration or oocyte pickup in ART cycles (low-quality evidence).• Intravenous fluids (plasma expanders) around the time of hCG administration or oocyte pickup in ART cycles (very low-quality evidence).• Progesterone for luteal phase support in ART cycles (low-quality evidence).• Coasting (withholding gonadotrophins) - a promising intervention that needs to be researched further for reduction of OHSS.On the basis of this overview, we must conclude that evidence is currently insufficient to support the widespread practice of embryo cryopreservation.

AUTHORS' CONCLUSIONS

Currently, 27 reviews in the Cochrane Library were conducted to report on or to try to report on OHSS in ART cycles. We identified four review protocols but no new registered titles that can potentially be included in this overview in the future. This overview provides the most up-to-date evidence on prevention of OHSS in ART cycles from all currently published Cochrane reviews on ART. Clinicians can use the evidence summarised in this overview to choose the best treatment regimen for individual patients - a regimen that not only reduces the chance of developing OHSS but does not compromise other outcomes such as pregnancy or live birth rate. Review results, however, are limited by the lack of recent primary studies or updated reviews. Furthermore, this overview can be used by policymakers in developing local and regional protocols or guidelines and can reveal knowledge gaps for future research.

Dopamine agonists for preventing ovarian hyperstimulation syndrome

BACKGROUND

Ovarian hyperstimulation syndrome (OHSS) is a potentially serious complication of ovarian stimulation in assisted reproduction technology (ART). It is characterised by enlarged ovaries and an acute fluid shift from the intravascular space to the third space, resulting in bloating, increased risk of venous thromboembolism and decreased organ perfusion. Most cases are mild, but forms of moderate or severe OHSS appear in 3% to 8% of in vitro fertilisation (IVF) cycles. The dopamine agonist cabergoline was introduced as a secondary prevention intervention for OHSS in women at high risk of OHSS undergoing ART treatment. As cabergoline seemed to be effective in preventing OHSS, other types of dopamine agonists, such as quinagolide and bromocriptine, have since been studied in ART to prevent OHSS.

OBJECTIVES

To assess the effectiveness and safety of dopamine agonists in preventing OHSS in high-risk women undergoing ART treatment.

SEARCH METHODS

We searched several databases from inception to August 2016 (Cochrane Gynaecology and Fertility Specialised Register of trials, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, CINAHL, PsycINFO, Clinicaltrials.gov and the World Health Organization International Trials Registry Platform (ICTRP)) for randomised controlled trials (RCTs) assessing the effect of dopamine agonist in preventing OHSS. We handsearched the reference lists of relevant studies.

SELECTION CRITERIA

We considered RCTs which compared dopamine agonists with placebo/no intervention or another intervention for preventing OHSS in high-risk women for inclusion. Primary outcome measures were incidence of moderate or severe OHSS and live birth rate. Secondary endpoints were clinical pregnancy rate, multiple pregnancy rate, miscarriage rate and any other adverse effects of the treatment.

DATA COLLECTION AND ANALYSIS

Two authors independently screened titles, abstracts and full texts of publications, selected studies, extracted data and assessed risk of bias. We resolved any disagreements by consensus. We reported pooled results as odds ratios (OR) and 95% confidence interval (95% CI) by the Mantel-Haenszel method. In addition, we graded the overall quality of the evidence using GRADE criteria.

MAIN RESULTS

The search identified 14 new RCTs since the last published version of this review, resulting in 16 included RCTs involving 2091 high-risk women for this updated review. They evaluated three types of dopamine agonists: cabergoline, quinagolide and bromocriptine.When compared with placebo or no intervention, dopamine agonists seemed effective in the prevention of moderate or severe OHSS (OR 0.27, 95% CI 0.19 to 0.39; 1022 participants; 8 studies; I² = 0%; moderate quality evidence). This suggests that if 29% of women undergoing ART experience moderate or severe OHSS, the use of dopamine agonists will lower this to 7% to 14% of women. There was no evidence of a difference in live birth rate, clinical pregnancy rate, multiple pregnancy rate or miscarriage rate (very low to moderate quality evidence). However, taking dopamine agonists (especially quinagolide) may increase the incidence of adverse events such as gastrointestinal adverse effects (OR 4.54, 95% CI 1.49 to 13.84; 264 participants; 2 studies; I² = 49%, very low quality evidence).When we compared dopamine agonist plus co-intervention with co-intervention, there was no evidence of a difference in the outcomes of moderate or severe OHSS, live birth rate, clinical pregnancy rate, miscarriage rate or adverse events. The co-interventions were hydroxyethyl starch (two RCTs) and albumin (one RCT).Cabergoline was associated with a lower risk of moderate or severe OHSS compared with human albumin (OR 0.21, 95% CI 0.12 to 0.38; 296 participants; 3 studies; I² = 72%). However, there was no evidence of a difference between cabergoline and hydroxyethyl starch, coasting (withholding any more ovarian stimulation for a few days) or prednisolone. There was an increased clinical pregnancy rate in the cabergoline group when cabergoline was compared with coasting (OR 2.65, 95% CI 1.13 to 6.21; 120 participants; 2 studies; I² = 0%). In other respects, there was no evidence of a difference in clinical pregnancy rate, multiple pregnancy rate or miscarriage rate between cabergoline and other active interventions.The quality of the evidence between dopamine agonist and placebo or no intervention ranged from very low to moderate, mainly due to poor reporting of study methods (mostly a lack of details on randomisation or blinding) and serious imprecision for some comparisons.

AUTHORS' CONCLUSIONS

Dopamine agonists appear to reduce the incidence of moderate or severe OHSS in women at high risk of OHSS (moderate quality evidence). If a fresh embryo transfer is performed, the use of dopamine agonists does not affect the pregnancy outcome (live birth rate, clinical pregnancy rate and miscarriage rate) (very low to moderate quality evidence). However, dopamine agonists might increase the risk of adverse events, such as gastrointestinal symptoms. Further research should focus on dose-finding, comparisons with other effective treatments and consideration of combination treatments. Therefore, large, well-designed and well-executed RCTs that involve more clinical endpoints (e.g., live birth rate) are necessary to further evaluate the role of dopamine agonists in OHSS prevention.

Volume expanders for the prevention of ovarian hyperstimulation syndrome

BACKGROUND

Ovarian hyperstimulation syndrome (OHSS) is a serious and potentially fatal complication of ovarian stimulation which affects 1% to 14% of all in vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI) cycles. A number of clinical studies with conflicting results have reported on the use of plasma expanders such as albumin, hydroxyethyl starch (HES), mannitol, polygeline and dextran as a possible intervention for the prevention of OHSS. Women with very high estradiol levels, high numbers of follicles or oocytes retrieved, and women with polycystic ovary syndrome (PCOS), are at particularly high risk of developing OHSS. Plasma expanders are not commonly used nowadays in ovarian hyperstimulation. This is mainly because clinical evidence on their effectiveness remains sparse, because of the low incidence of moderate and severe ovarian hyperstimulation syndrome (OHSS) and the simultaneous introduction of mild stimulation approaches, gonadotropin-releasing hormone (GnRH) antagonist protocols and the freeze-all strategy for the prevention of OHSS.

OBJECTIVES

To review the effectiveness and safety of administration of volume expanders for the prevention of moderate and severe ovarian hyperstimulation syndrome (OHSS) in high-risk women undergoing IVF or ICSI treatment cycles.

SEARCH METHODS

We searched databases including the Cochrane Gynaecology and Fertility Group Specialised Register of controlled trials, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase and trial registers to September 2015; no date restrictions were used as new comparators were included in this search. The references of relevant publications were also searched. We attempted to contact authors to provide or clarify data that were unclear from trial or abstract reports.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing volume expanders versus placebo or no treatment for the prevention of OHSS in high-risk women undergoing ovarian hyperstimulation as part of any assisted reproductive technique.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected the studies, assessed risk of bias and extracted relevant data. The primary review outcome was moderate or severe OHSS. Other outcomes were live birth, pregnancy and adverse events. We combined data to calculate pooled Peto odds ratios (ORs) and 95% confidence intervals (CIs) for each intervention. Statistical heterogeneity was assessed using the I(2) statistic. We assessed the overall quality of the evidence for each comparison, using GRADE methods.

MAIN RESULTS

We included nine RCTs (1867 women) comparing human albumin (seven RCTs) or HES (two RCTs) or mannitol (one RCT) versus placebo or no treatment for prevention of OHSS. The evidence was very low to moderate quality for all comparisons. The main limitations were imprecision, poor reporting of study methods, and failure to blind outcome assessment.There was evidence of a beneficial effect of intravenous albumin on OHSS, though heterogeneity was substantial (Peto OR 0.67 95% CI 0.47 to 0.95, seven studies, 1452 high risk women; I² = 69%, very low quality evidence) . This suggests that if the rate of moderate or severe OHSS with no treatment is 12%, it will be about 9% (6% to12%) with the use of intravenous albumin. However, there was evidence of a detrimental effect on pregnancy rates (Peto OR 0.72 95% CI 0.55 to 0.94, I² = 42%, seven studies 1069 high risk women, moderate quality evidence). This suggests that if the chance of pregnancy is 40% without treatment, it will be about 32% (27% to 38%) with the use of albumin.There was evidence of a beneficial effect of HES on OHSS (Peto OR 0.27 95% CI 0.12 to 0.59, I² = 0%, two studies, 272 women, very low quality evidence). This suggests that if the rate of moderate or severe OHSS with no treatment is 16%, it will be about 5% (2% to 10%) with the use of HES. There was no evidence of an effect on pregnancy rates (Peto OR 1.20 95% CI 0.49 to 2.93, one study, 168 women, very low quality evidence).There was evidence of a beneficial effect of mannitol on OHSS (Peto OR 0.38, 95% CI 0.22 to 0.64, one study, 226 women with PCOS, low quality evidence). This means that if the risk of moderate or severe OHSS with no treatment is 52%, it will be about 29% (19% to 41%) with mannitol. There was no evidence of an effect on pregnancy rates (Peto OR 0.85 95% CI 0.47 to 1.55; one study, 226 women, low quality evidence).Live birth rates were not reported in any of the studies. Adverse events appeared to be uncommon, but were too poorly reported to reach any firm conclusions.

AUTHORS' CONCLUSIONS

Evidence suggests that the plasma expanders assessed in this review (human albumin, HES and mannitol) reduce rates of moderate and severe OHSS in women at high risk. Adverse events appear to be uncommon, but were too poorly reported to reach any firm conclusions, and there were no data on live birth. However, there was evidence that human albumin reduces pregnancy rates. While there was no evidence that HES, or mannitol had any influence on pregnancy rates, the evidence of effectiveness was based on very few trials which need to be confirmed in additional, larger randomised controlled trials (RCTs) before they should be considered for routine use in clinical practice.

Development of new method and protocol for cryopreservation related to embryo and oocytes freezing in terms of fertilization rate: A comparative study including review of literature

Background:

Cryopreservation is basically related to meritorious thin samples or small clumps of cells that are cooled quickly without loss. Our main objective is to establish and formulate an innovative method and protocol development for cryopreservation as a gold standard for clinical uses in laboratory practice and treatment. The knowledge regarding usefulness of cryopreservation in clinical practice is essential to carry forward the clinical practice and research.

Materials and Methods:

We are trying to compare different methods of cryopreservation (in two dozen of cells) at the same time we compare the embryo and oocyte freezing interms of fertilization rate according to the International standard protocol.

Results:

The combination of cryoprotectants and regimes of rapid cooling and rinsing during warming often allows successful cryopreservation of biological materials, particularly cell suspensions or thin tissue samples. Examples include semen, blood, tissue samples like tumors, histological cross-sections, human eggs and human embryos. Although presently many studies have reported that the children born from frozen embryos or “frosties,” show consistently positive results with no increase in birth defects or development abnormalities is quite good enough and similar to our study (50–85%).

Conclusions:

We ensure that cryopreservation technology provided useful cell survivability, tissue and organ preservation in a proper way. Although it varies according to different laboratory conditions, it is certainly beneficial for patient's treatment and research. Further studies are needed for standardization and development of new protocol.

Assisted reproductive technology: an overview of Cochrane Reviews

BACKGROUND

As many as one in six couples will encounter problems with fertility, defined as failure to achieve a clinical pregnancy after regular intercourse for 12 months. Increasingly, couples are turning to assisted reproductive technology (ART) for help with conceiving and ultimately giving birth to a healthy live baby of their own. Fertility treatments are complex, and each ART cycle consists of several steps. If one of the steps is incorrectly applied, the stakes are high as conception may not occur. With this in mind, it is important that each step of the ART cycle is supported by good evidence from well-designed studies.

OBJECTIVES

To summarise the evidence from Cochrane systematic reviews on procedures and treatment options available to couples with subfertility undergoing assisted reproductive technology (ART).

METHODS

Published Cochrane systematic reviews of couples undergoing ART (in vitro fertilisation or intracytoplasmic sperm injection) were eligible for inclusion in the overview. We also identified Cochrane reviews in preparation, for future inclusion.The outcomes of the overview were live birth (primary outcome), clinical pregnancy, multiple pregnancy, miscarriage and ovarian hyperstimulation syndrome (secondary outcomes). Studies of intrauterine insemination and ovulation induction were excluded.Selection of systematic reviews, data extraction and quality assessment were undertaken in duplicate. Review quality was assessed by using the AMSTAR tool. Reviews were organised by their relevance to specific stages in the ART cycle. Their findings were summarised in the text and data for each outcome were reported in 'Additional tables'.

MAIN RESULTS

Fifty-nine systematic reviews published in The Cochrane Library up to July 2015 were included. All were high quality. Thirty-two reviews identified interventions that were effective (n = 19) or promising (n = 13), 14 reviews identified interventions that were either ineffective (n = 2) or possibly ineffective (n = 12), and 13 reviews were unable to draw conclusions due to lack of evidence.An additional 11 protocols and five titles were identified for future inclusion in this overview.

AUTHORS' CONCLUSIONS

This overview provides the most up to date evidence on ART cycles from systematic reviews of randomised controlled trials. Fertility treatments are costly and the stakes are high. Using the best available evidence to optimise outcomes is best practice. The evidence from this overview could be used to develop clinical practice guidelines and protocols for use in daily clinical practice, in order to improve live birth rates and reduce rates of multiple pregnancy, cycle cancellation and ovarian hyperstimulation syndrome.

Prevention of Ovarian Hyperstimulation Syndrome: A Review

The following review aims to examine the available evidence to guide best practice in preventing ovarian hyperstimulation syndrome (OHSS). As it stands, there is no single method to completely prevent OHSS. There seems to be a benefit, however, in categorizing women based on their risk of OHSS and individualizing treatments to curtail their chances of developing the syndrome. At present, both Anti-Müllerian Hormone and the antral follicle count seem to be promising in this regard. Both available and upcoming therapies are also reviewed to give a broad perspective to clinicians with regard to management options. At present, we recommend the use of a "step-up" regimen for ovulation induction, adjunct metformin utilization, utilizing a GnRH agonist as an ovulation trigger, and cabergoline usage. A summary of recommendations is also made available for ease of clinical application. In addition, areas for potential research are also identified where relevant.

Assisted reproductive technology: an overview of Cochrane reviews

BACKGROUND

As many as one in six couples will encounter problems with fertility, defined as failure to achieve a clinical pregnancy after regular intercourse for 12 months. Increasingly, couples are turning to assisted reproductive technology (ART) for help with conceiving and ultimately giving birth to a healthy live baby of their own. Fertility treatments are complex, and each ART cycle consists of several steps. If one of the steps is incorrectly applied, the stakes are high as conception may not occur. With this in mind, it is important that each step of the ART cycle is supported by good evidence from well-designed studies.

OBJECTIVES

To summarise the evidence from Cochrane systematic reviews on procedures and treatment options available to couples with subfertility undergoing assisted reproductive technology (ART).

METHODS

Published Cochrane systematic reviews of couples undergoing ART (in vitro fertilisation or intracytoplasmic sperm injection) were eligible for inclusion in the overview. We also identified Cochrane reviews in preparation, for future inclusion.The outcomes of the overview were live birth (primary outcome), clinical pregnancy, multiple pregnancy, miscarriage and ovarian hyperstimulation syndrome (secondary outcomes). Studies of intrauterine insemination and ovulation induction were excluded.Selection of systematic reviews, data extraction and quality assessment were undertaken in duplicate. Review quality was assessed by using the AMSTAR tool. Reviews were organised by their relevance to specific stages in the ART cycle. Their findings were summarised in the text and data for each outcome were reported in 'Additional tables'.

MAIN RESULTS

Fifty-eight systematic reviews published in The Cochrane Library were included. All were high quality. Thirty-two reviews identified interventions that were effective (n = 19) or promising (n = 13), 14 reviews identified interventions that were either ineffective (n = 3) or possibly ineffective (n=11), and 12 reviews were unable to draw conclusions due to lack of evidence.An additional 11 protocols and one title were identified for future inclusion in this overview.

AUTHORS' CONCLUSIONS

This overview provides the most up to date evidence on ART cycles from systematic reviews of randomised controlled trials. Fertility treatments are costly and the stakes are high. Using the best available evidence to optimise outcomes is best practice. The evidence from this overview could be used to develop clinical practice guidelines and protocols for use in daily clinical practice, in order to improve live birth rates and reduce rates of multiple pregnancy, cycle cancellation and ovarian hyperstimulation syndrome.

Assisted reproductive technologies (ARTs): evaluation of evidence to support public policy development

Over the years, IVF/ICSI protocols have continued to evolve with efforts to improve outcomes. As a result, treatment success may be related to certain procedural factors, including number of embryos transferred and stage at which they are transferred. This review aims to assess the safety and effectiveness of IVF/ICSI in comparison to spontaneous conception and less invasive ARTs and the impact of procedure-related factors on the outcomes of IVF/ICSI in order to support the development of local clinical and policy guidance. Following Cochrane Collaboration guidelines and the PRISMA statement, a comprehensive systematic review of literature examining the impact of procedural characteristics on the safety or effectiveness of IVF/ICSI from 2007 to date was performed. 33 systematic reviews and 3 primary studies evaluating the impact of procedural differences, IVF/ICSI in comparison to less invasive ARTs, and ARTs in comparison to spontaneous conception were found. IVF was shown to offer significant benefits over no treatment and IUI in achieving pregnancy and live birth among couples with endometriosis or unexplained infertility. Frozen and blastocyst-stage embryo transfers were as effective as fresh and cleavage-stage embryo transfers, respectively. In comparison to single embryo transfer, double embryo transfer significantly increased pregnancy, live birth and multiple pregnancy/birth rates. IVF/ICSI was associated with more complications during pregnancy and delivery, and in infants compared to naturally conceived pregnancies, particularly when multiple embryo transfer was used. Frozen embryo transfer had fewer adverse events during pregnancy and delivery than fresh embryo transfer, and was at least as safe in terms of infant outcomes. The potential complications of IVF/ICSI may be minimized through procedural choices, but such choices often impact effectiveness. Thus, in developing clinical and policy guidance around IVF/ICSI, the risk-benefit trade-offs patients and providers are willing to accept must be carefully considered.

Use of gonadotropin-releasing hormone agonist trigger during in vitro fertilization is associated with similar endocrine profiles and oocyte measures in women with and without polycystic ovary syndrome

OBJECTIVE

To compare endocrine profiles and IVF outcomes after using GnRH agonists (GnRHa) to trigger final oocyte maturation in women with polycystic ovary syndrome (PCOS) with other hyper-responders.

DESIGN

Retrospective cohort study.

SETTING

Academic center.

PATIENT(S)

Forty women with PCOS and 74 hyper-responders without PCOS.

INTERVENTION(S)

GnRHa trigger.

MAIN OUTCOME MEASURE(S)

Number of oocytes.

RESULT(S)

Serum E2, LH, and P levels on the day of GnRHa trigger and the day after trigger did not differ significantly between groups. There were no significant differences in total number of oocytes or percent mature oocytes obtained between groups after controlling for age, antral follicle count, and total days of stimulation. The overall rate of no retrieval of oocytes after trigger was low (2.6%). Fertilization, implantation, clinical pregnancy, and live-birth rates were similar in the two groups. No patients developed ovarian hyperstimulation syndrome (OHSS).

CONCLUSION(S)

The similar post-GnRHa trigger hormone profiles and mature oocyte yield support the routine use of GnRHa trigger to prevent OHSS in women with PCOS.

Metformin decreases the incidence of ovarian hyperstimulation syndrome: an experimental study

Background

In assisted reproduction cycles, gonadotropins are administered to obtain a greater number of oocytes. A majority of patients do not have an adverse response; however, approximately 3-6% develop ovarian hyperstimulation syndrome (OHSS). Metformin reduces the risk of OHSS but little is known about the possible effects and mechanisms of action involved.

Objective

To evaluate whether metformin attenuates some of the ovarian adverse effects caused by OHSS and to study the mechanisms involved.

Material and methods

A rat OHSS model was used to investigate the effects of metformin administration. Ovarian histology and follicle counting were performed in ovarian sections stained with Masson trichrome. Vascular permeability was measured by the release of intravenously injected Evans Blue dye (EB). VEGF levels were measured by commercially immunosorbent assay kit. COX-2 protein expression was evaluated by western blot and NOS levels were analyses by immunohistochemistry.

Results

Animals of the OHSS group showed similar physiopathology characteristics to the human syndrome: increased body weight, elevated progesterone and estradiol levels (P<0.001), increased number of corpora lutea (P<0.001), higher ovarian VEGF levels and vascular permeability (P<0.001 and P<0.01); and treatment with metformin prevented this effect (OHSS+M group; P<0.05). The vasoactive factors: COX-2 and NOS were increased in the ovaries of the OHSS group (P<0.05 and P<0.01) and metformin normalized their expression (P<0.05); suggesting that metformin has a role preventing the increased in vascular permeability caused by the syndrome.

Conclusion

Metformin has a beneficial effect preventing OHSS by reducing the increase in: body weight, circulating progesterone and estradiol and vascular permeability. These effects of metformin are mediated by inhibiting the increased of the vasoactive molecules: VEGF, COX-2 and partially NOS. Molecules that are increased in OHSS and are responsible for a variety of the symptoms related to OHSS.

Assisted reproductive technology: an overview of Cochrane Reviews

BACKGROUND

As many as one in six couples will encounter problems with fertility, defined as failure to achieve a clinical pregnancy after regular intercourse for 12 months. Increasingly, couples are turning to assisted reproductive technology (ART) for help with conceiving and ultimately giving birth to a healthy live baby of their own. Fertility treatments are complex, and each ART cycle consists of several steps. If one of the steps is incorrectly applied, the stakes are high as conception may not occur. With this in mind, it is important that each step of the ART cycle is supported by good evidence from well-designed studies.

OBJECTIVES

To summarise the evidence from Cochrane systematic reviews on procedures and treatment options available to couples with subfertility undergoing assisted reproductive technology (ART).

METHODS

Published Cochrane systematic reviews of couples undergoing ART (in vitro fertilisation or intracytoplasmic sperm injection) were eligible for inclusion in the overview. We also identified Cochrane reviews in preparation, for future inclusion.The outcomes of the overview were live birth (primary outcome), clinical pregnancy, multiple pregnancy, miscarriage and ovarian hyperstimulation syndrome (secondary outcomes). Studies of intrauterine insemination and ovulation induction were excluded.Selection of systematic reviews, data extraction and quality assessment were undertaken in duplicate. Review quality was assessed by using the AMSTAR tool. Reviews were organised by their relevance to specific stages in the ART cycle. Their findings were summarised in the text and data for each outcome were reported in 'Additional tables'.

MAIN RESULTS

Fifty-four systematic reviews published in The Cochrane Library were included. All were high quality. Thirty reviews identified interventions that were effective (n = 18) or promising (n = 12), 13 reviews identified interventions that were either ineffective (n = 3) or possibly ineffective (n=10), and 11 reviews were unable to draw conclusions due to lack of evidence.An additional 15 protocols and two titles were identified for future inclusion in this overview.

AUTHORS' CONCLUSIONS

This overview provides the most up to date evidence on ART cycles from systematic reviews of randomised controlled trials. Fertility treatments are costly and the stakes are high. Using the best available evidence to optimise outcomes is best practice. The evidence from this overview could be used to develop clinical practice guidelines and protocols for use in daily clinical practice, in order to improve live birth rates and reduce rates of multiple pregnancy, cycle cancellation and ovarian hyperstimulation syndrome.

Update in polycystic ovary syndrome: new criteria of diagnosis and treatment in Japan

Polycystic ovary syndrome (PCOS) is the most frequent endocrine disorder in women of reproductive age. In 2006 the Japanese Society of Obstetrics and Gynecology (JSOG) proposed new, revised diagnostic criteria that in the future could also be valued internationally. Based on the new diagnostic criteria, the JSOG has also proposed the revised treatment criteria in 2008. In PCOS obese patients desiring children, weight loss and exercise is recommended. Nonobese patients, or those obese women who do not ovulate after lifestyle changes, are submitted to ovulation-induction therapy with clomiphene citrate (CC). Obese CC-resistant patients who have impaired glucose tolerance or insulin resistance are treated with a combination of metformin and CC. If these treatments options are unsuccessful, ovulation induction with exogenous gonadotropin therapy or laparoscopic ovarian drilling (LOD) is recommended. A low-dose step-up regimen is recommended with careful monitoring in order to reduce the risk of ovarian hyperstimulation syndrome (OHSS) and multiple pregnancies. Alternatively, with LOD high successful pregnancy rates of around 60 % are expected with a low risk of multiple pregnancies. If ovulation induction is unsuccessful, IVF-ET treatment is indicated. In high OHSS-risk patients, systematic embryo freezing and subsequent frozen embryo transfer cycles are recommended. In nonobese, anovulatory PCOS patients not desiring children, pharmacological treatments such as Holmström, Kaufmann regimens or low-dose oral anticonceptives are used to induce regular withdrawal bleeding. These treatments are especially important for preventing endometrial hyperplasia and endometrial cancer. These new diagnostic and treatment criteria hopefully will contribute to an improved care of PCOS patients in Japan.

Current approach to fertility preservation by embryo cryopreservation

The ovaries are susceptible to damage following treatment with gonadotoxic chemotherapy, pelvic radiotherapy, and/or ovarian surgery. Gonadotoxic treatments have also been used in patients with various nonmalignant systemic diseases. Any women of reproductive age with a sufficiently high risk of developing future ovarian failure due to those medical interventions may benefit from embryo cryopreservation though the tools of assessment of such a risk are still not very precise. Furthermore, the risk assessment can be influenced by many other factors such as the delay expected after chemotherapy and the number of children desired in the future. Embryo cryopreservation is an established and most successful method of fertility preservation when there is sufficient time available to perform ovarian stimulation. This publication will review the current state, approach, and indications of embryo cryopreservation for fertility preservation.

A unique human chorionic gonadotropin antagonist suppresses ovarian hyperstimulation syndrome in rats

Ovarian hyperstimulation syndrome (OHSS) is a complication of in vitro fertilization associated with physiological changes after hCG administration to induce final oocyte maturation. It presents as widespread increases in vascular permeability and, in rare cases, results in cycle cancellation, multi-organ dysfunction, and pregnancy termination. These physiological changes are due primarily to activation of the vascular endothelial growth factor (VEGF) system in response to exogenous human chorionic gonadotropin (hCG). An hCG antagonist (hCG-Ant) could attenuate these effects by competitively binding to the LH/CG receptor, thereby blocking LH activity in vivo. We expressed a form of hCG that lacks three of its four N-linked glycosylation sites and tested its efficacy as an antagonist. The hCG-Ant binds the LH receptor with an affinity similar to native hCG and inhibits cAMP response in vitro. In a rat model for ovarian stimulation, hCG-Ant dramatically reduces ovulation and steroid hormone production. In a well-established rat OHSS model, vascular permeability and vascular endothelial growth factor (VEGF) expression are dramatically reduced after hCG-Ant treatment. Finally, hCG-Ant does not appear to alter blastocyst development when given after hCG in mice. These studies demonstrate that removing specific glycosylation sites on native hCG can produce an hCG-Ant that is capable of binding without activating the LH receptor and blocking the actions of hCG. Thus hCG-Ant will be investigated as a potential therapy for OHSS.

Approaches to improve the diagnosis and management of infertility

BACKGROUND Recent advances in our understanding of the causes of infertility and of assisted reproductive technology (ART) have led to the development of complex diagnostic tools, prognostic models and treatment options. The Third Evian Annual Reproduction (EVAR) Workshop Meeting was held on 26-27 April 2008 to evaluate evidence supporting current approaches to the diagnosis and management of infertility and to identify areas for future research efforts. METHODS Specialist reproductive medicine clinicians and scientists delivered presentations based on published literature and ongoing research on patient work-up, ovarian stimulation and embryo quality assessment during ART. This report is based on the expert presentations and subsequent group discussions and was supplemented with publications from literature searches and the authors' knowledge. RESULTS It was agreed that single embryo transfer (SET) should be used with increasing frequency in cycles of ART. Continued improvements in cryopreservation techniques, which improve pregnancy rates using supernumerary frozen embryos, are expected to augment the global uptake of SET. Adaptation and personalization of fertility therapy may help to optimize efficacy and safety outcomes for individual patients. Prognostic modelling and personalized management strategies based on individual patient characteristics may prove to represent real progress towards improved treatment. However, at present, there is limited good-quality evidence to support the use of these individualized approaches. CONCLUSIONS Greater quality control and standardization of clinical and laboratory evaluations are required to optimize ART practices and improve individual patient outcomes. Well-designed, good-quality studies are required to drive improvements to the diagnosis and management of ART processes.

Ovarian hyperstimulation syndrome and prophylactic human embryo cryopreservation: analysis of reproductive outcome following thawed embryo transfer

Objective

To review utilisation of elective embryo cryopreservation in the expectant management of patients at risk for developing ovarian hyperstimulation syndrome (OHSS), and report on reproductive outcome following transfer of thawed embryos.

Materials and methods

Medical records were reviewed for patients undergoing IVF from 2000–2008 to identify cases at risk for OHSS where cryopreservation was electively performed on all embryos at the 2 pn stage. Patient age, total number of oocytes retrieved, number of 2 pn embryos cryopreserved, interval between retrieval and thaw/transfer, number (and developmental stage) of embryos transferred (ET), and delivery rate after IVF were recorded for all patients.

Results

From a total of 2892 IVF cycles undertaken during the study period, 51 IVF cases (1.8%) were noted where follicle number exceeded 20 and pelvic fluid collection was present. Elective embryo freeze was performed as OHSS prophylaxis in each instance. Mean (± SD) age of these patients was 32 ± 3.8 yrs. Average number of oocytes retrieved in this group was 23 ± 8.7, which after fertilisation yielded an average of 14 ± 5.7 embryos cryopreserved per patient. Thaw and ET was performed an average of 115 ± 65 d (range 30–377 d) after oocyte retrieval with a mean of 2 ± 0.6 embryos transferred. Grow-out to blastocyst stage was achieved in 88.2% of cases. Delivery/livebirth rate was 33.3% per initiated cycle and 43.6% per transfer. Non-transferred blastocysts remained in cryostorage for 24 of 51 patients (46.1%) after ET, with an average of 3 ± 3 blastocysts refrozen per patient.

Conclusion

OHSS prophylaxis was used in 1.8% of IVF cycles at this institution; no serious OHSS complications were encountered during the study period. Management based on elective 2 pn embryo cryopreservation with subsequent thaw and grow-out to blastocyst stage for transfer did not appear to compromise embryo viability or overall reproductive outcome. For these patients, immediate elective embryo cryopreservation and delay of ET by as little as 30 d allowed for satisfactory conclusion of the IVF sequence, yielding a livebirth-delivery rate (per ET) >40%.

Optimal follicle and oocyte numbers for cryopreservation of all embryos in IVF cycles at risk of OHSS

Ovarian hyperstimulation syndrome (OHSS) is a rare but potentially fatal complication of IVF treatment. The risk of OHSS increases with increasing numbers of follicles aspirated and oocytes retrieved, but there is little evidence to support whether threshold values of either can be used to correctly predict OHSS. Since the most severe forms of OHSS are usually associated with pregnancy, cryopreservation of all embryos may prevent this. The authors attempted to find thresholds of follicle and oocyte numbers that would optimally predict OHSS, through a retrospective analysis of 2253 consecutive cycles of IVF/intracytoplasmic sperm injection treatment reaching oocyte retrieval, between 1 January 2003 and 31 March 2006. Receiver operator characteristic (ROC) curves were calculated for both parameters, to determine threshold values that might predict OHSS in women with > or =20 oocytes. For the prediction of early onset OHSS, ROC curves showed that an optimal balance between sensitivity and specificity was achieved using thresholds of 24 oocytes (79%, 60%) and 29 follicles (82%, 65%) respectively. Using these thresholds, cryopreservation of all embryos may be offered as an alternative to cancellation of a treatment cycle due to excessive ovarian response, thus minimizing the number of unnecessary interventions while still correctly predicting most cases of early onset OHSS.