Preventive attitude of physicians to avoid OHSS in IVF patients

GnRH agonist-only trigger, compared to dual trigger, reduces oocyte retrieval rate in high responders without affecting cumulative live birth rate

Introduction

This study compared, in high responders undergoing IVF treatment, GnRH agonist-only trigger and dual trigger on oocyte retrieval rate and cumulative live birth rate (LBR). The aim was to determine if the GnRH agonist-only triggers had provided outcomes comparable to dual trigger, while minimizing the risk of ovarian hyperstimulation syndrome (OHSS).

Materials and methods

A retrospective, matched case-control study was conducted at Taichung Veterans General Hospital, Taiwan, including women who underwent IVF/ICSI between January 1, 2014, and December 31, 2022. Inclusion criteria were: GnRH antagonist protocol and estrogen level >3,000 pg/ml on trigger day. Exclusion criteria were: immune/metabolic diseases, donated oocytes, and mixed stimulation cycles. Propensity score matching was applied to balance age, AMH level, and oocyte number between the GnRH agonist-only and dual trigger groups. Outcomes were analyzed for patients who had complete treatment cycles, focusing on oocyte retrieval rate and cumulative LBR.

Results

We analyzed 116 cycles in the agonist-only group, and 232 cycles in the dual trigger group. No inter-group difference was found in their age, BMI, and AMH levels. The dual trigger group had a higher oocyte retrieval rate (93% vs. 80%; p <0.05), while fertilization rates, blastocyst formation rates, and cumulative LBR were comparable. Notably, no OHSS cases had been reported in the GnRH agonist-only group, compared with 7 cases in the dual trigger group.

Conclusion

GnRH agonist-only triggers resulted in a lower oocyte retrieval rate compared to dual triggers but did not significantly affect cumulative LBR in high responders. This approach effectively reduces OHSS risk without compromising pregnancy outcomes, making it a preferable option in freeze-all strategies, despite a longer oocyte pick-up duration and a medium cost. GnRH agonist-only trigger, however, may not be suitable for fresh embryo transfers or patients with low serum LH levels on trigger day.

Nomogram Model to Predict the Probability of Ovarian Hyperstimulation Syndrome in the Treatment of Patients With Polycystic Ovary Syndrome

Objective

The objective of this study was to explore the risk factors of ovarian hyperstimulation syndrome (OHSS) in patients with polycystic ovary syndrome (PCOS) undergoing in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) and to establish a nomogram model evaluate the probability of OHSS in PCOS patients.

Methods

We retrospectively analyzed clinical data from 4,351 patients with PCOS receiving IVF/ICSI in our reproductive medical center. The clinical cases were randomly divided into a modeling group (3,231 cases) and a verification group (1,120 cases) according to a ratio of about 3:1. The independent risk factors correlation with the occurrence of OHSS was identified by logistic regression analysis. Based on the selected independent risk factors and correlated regression coefficients, we established a nomogram model to predict the probability of OHSS in PCOS patients, and the predictive accuracy of the model was measured using the area under the receiver operating curve (AUC).

Results

Univariate and multivariate logistic regression analyses showed that FSH (OR, 0.901; 95% CI, 0.847-0.958; P<0.001), AMH (OR, 1.259; 95% CI, 1.206-1.315; P<0.001), E2 value on the day of hCG injection (OR, 1.122; 95% CI, 1.021-1.253; P<0.001), total dosage of Gn used (OR, 1.010; 95% CI, 1.002-1.016; P=0.041), and follicle number on the day of hCG injection (OR, 0.134; 95% CI, 1.020-1.261; P=0.020) are the independent risk factors for OHSS in PCOS patients. The AUC of the modeling group is 0.827 (95% CI, 0.795-0.859), and the AUC of the verification group is 0.757 (95% CI, 0.733-0.782).

Conclusion

The newly established nomogram model has proven to be a novel tool that can effectively, easily, and intuitively predict the probability of OHSS in the patients with PCOS, by which the clinician can set up a better clinical management strategies for conducting a precise personal therapy.

The effect of early coasting on blastocyst development and outcome following blastocyst transfer in IVF/ICSI programme

Objective

Coasting is a well-known strategy to decrease severity of Ovarian Hyperstimulation Syndrome (OHSS). The purpose of this study is to assess the effect of Coasting on blastocyst development and subsequent clinical outcome following exclusive blastocyst transfer.

Methods

We conducted an observational cohort study of patients having blastocyst transfer following IVF/ICSI treatment. Patients undergoing IVF/ICSI cycles were included in the study. Patients at risk of OHSS were coasted. Outcome following exclusive blastocyst transfer was compared between coasted and non-coasted groups. The main outcome measures were the rate of blastocyst development and live birth rates in coasted and non-coasted cycles. Within coasted cycles, outcome was further analysed based on coasting duration and serum estradiol (E₂) drop (difference between peak E₂ and E₂ on day of HCG).

Results

A total of 166 coasted cycles and 656 non-coasted cycles had blastocyst transfer. Blastocyst development (45.97% vs. 48.6%) and live birth rates (45.18% vs. 43.44%) were not significantly different between coasted and non-coasted cycles. The overall clinical pregnancy (54.21% vs. 49.08%) and implantation rates (43.95% vs. 39.54%) following blastocyst transfer in coasted cycles were not significantly different from those of non-coasted cycles.

Conclusion

Coasting duration up to 6 days and drop in serum E₂ levels did not compromise blastocyst development, implantation, clinical pregnancy or live birth rates. We conclude that coasting with subsequent blastocyst transfer can be used as an effective strategy in patients at risk of OHSS with no detrimental effects on blastocyst development or live birth outcome.

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

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

Is Coasting Valuable in All Patients with Any Cause of Infertility?

OBJECTIVES

This study aimed to assess the influence of coasting duration on the number and quality of oocytes and fertilization rate in male factor infertile women and those with polycystic ovary syndrome (PCOS).

METHODS

In this prospective observational follow-up study, 114 patients undergoing coasting (53 women with male factor infertility and 61 women with PCOS) were evaluated at the Royan Institute Research Center, Iran, between 2010 and 2012.

RESULTS

The results were analyzed according to the coasting periods of 1-4 days. In normal females, the number of oocytes retrieved was significantly reduced after the second day (p = 0.004). In addition, a statistically significant drop was observed in the number of metaphase II oocytes and fertilization rate after the third day (p = 0.006 and p = 0.006, respectively). No significant differences were observed in the number and quality of oocytes retrieved and fertilization rate with regard to coasting days in PCOS patients.

CONCLUSION

Coasting with duration of more than three days should be performed with caution in normal females who are at risk of developing 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.

The prevention of ovarian hyperstimulation syndrome

OBJECTIVE

To review the clinical aspects of ovarian hyperstimulation syndrome and provide recommendations on its prevention.

OPTIONS

Preventative measures, early recognition, and prompt systematic supportive care will help avoid poor outcomes.

OUTCOMES

Establish guidelines to assist in the prevention of ovarian hyperstimulation syndrome, early recognition of the condition when it occurs, and provision of appropriate supportive measures in the correct setting.

EVIDENCE

Published literature was retrieved through searches of Medline, Embase, and the Cochrane Library from 2011 to 2013 using appropriate controlled vocabulary ([OHSS] ovarian hyperstimulation syndrome and: agonist IVF, antagonist IVF, metformin, HCG, gonadotropin, coasting, freeze all, agonist trigger, progesterone) and key words (ovarian hyperstimulation syndrome, ovarian stimulation, gonadotropin, human chorionic gonadotropin, prevention). Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies published in English. There were no date restrictions. Searches were updated on a regular basis and incorporated in the guideline to February 2013. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies.

VALUES

The quality of evidence in this document was rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care (Table 1). Summary Statements 1. The particular follicle-stimulating hormone formulation used for ovarian stimulation does not affect the incidence of ovarian hyperstimulation syndrome. (I) 2. Coasting may reduce the incidence of severe ovarian hyperstimulation syndrome. (III) 3. Coasting for longer than 3 days reduces in vitro fertilization pregnancy rates. (II-2) 4. The use of either luteinizing hormone or human chorionic gonadotropin for final oocyte maturation does not influence the incidence of ovarian hyperstimulation syndrome. (I) 5. There is no clear published evidence that lowering the human chorionic gonadotropin dose will result in a decrease in the rate of ovarian hyperstimulation syndrome. (III) 6. Cabergoline starting from the day of human chorionic gonadotropin reduces the incidence of ovarian hyperstimulation syndrome in patients at higher risk and does not appear to lower in vitro fertilization pregnancy rates. (II-2) 7. Avoiding pregnancy by freezing all embryos will prevent severe prolonged ovarian hyperstimulation syndrome in patients at high risk. (II-2) 8. Pregnancy rates are not affected when using gonadotropin-releasing hormone (GnRH) agonists in GnRH antagonist protocols for final egg maturation when embryos are frozen by vitrification for later transfer. (II-2) Recommendations 1. The addition of metformin should be considered in patients with polycystic ovarian syndrome who are undergoing in vitro fertilization because it may reduce the incidence of ovarian hyperstimulation syndrome. (I-A) 2. Gonadotropin dosing should be carefully individualized, taking into account the patient's age, body mass, antral follicle count, and previous response to gonadotropins. (II-3B) 3. Cycle cancellation before administration of human chorionic gonadatropin is an effective strategy for the prevention of ovarian hyperstimulation syndrome, but the emotional and financial burden it imposes on patients should be considered before the cycle is cancelled. (III-C) 4. Gonadotropin-releasing hormone (GnRH) antagonist stimulation protocols are recommended in patients at high risk for ovarian hyperstimulation syndrome (OHSS). The risk of severe OHSS in patients on GnRH antagonist protocols who have a very robust ovarian stimulation response can be reduced by using a GnRH agonist as a substitute for human chorionic gonadotropin to trigger final oocyte maturation. (I-B) 5. A gonadotropin-releasing hormone (GnRH) antagonist protocol with a GnRH agonist trigger for final oocyte maturation is recommended for donor oocyte and fertility preservation cycles. (III-C) 6. Albumin or other plasma expanders at the time of egg retrieval are not recommended for the prevention of ovarian hyperstimulation syndrome. (I-E) 7. Elective single embryo transfer is recommended in patients at high risk for ovarian hyperstimulation syndrome. (III-C) 8. Progesterone, rather than human chorionic gonadotropin, should be used for luteal phase support. (I-A) 9. Outpatient culdocentesis should be considered for the prevention of disease progression in severe ovarian hyperstimulation syndrome. (II-2B).

Does the serum E2 level change following coasting treatment strategy to prevent ovarian hyperstimulation syndrome impact cycle outcomes during controlled ovarian hyperstimulation and in vitro fertilization procedure?

OBJECTIVE

Ovarian hyperstimulation syndrome (OHSS) remains as a clinical problem for hyperresponder patients during controlled ovarian hyperstimulation and in vitro fertilization (COH-IVF) procedure. Herein, we aimed to evaluate the COH-IVF outcomes in hyperresponder patients managed with coasting treatment strategy for OHSS prevention regarding the establishment of clinical pregnancy as an endpoint of the treatment cycle.

MATERIALS AND METHODS

The medical records related to the COH-IVF outcome in 119 hyperresponder patients who have exhibited a serum estradiol level greater than or equal to 3000 pg/mL were evaluated. The study was conducted on a total of 119 patients, 98 of whom have been treated by coasting or coasting with GnRH antagonist co-treatment strategies, while the remaining 21 women (control group) have not been managed with coasting treatment. The COH and IVF-ET outcomes in the 119 patients were compared based on the coasting treatment situation.

RESULTS

Among the women who received coasting treatment, the number of patients demonstrating E2 level decrement and also E2 level decrement rate after coasting were similar between patients with and without clinical pregnancy. Total gonadotropin dose, 2PN number, embryo number, and fertilization rate were significantly higher in the patients with a clinical pregnancy.

CONCLUSION

The coasting treatment is a clinically useful preventive strategy for OHSS avoidance. GnRH antagonist co-treatment decreases the duration of coasting although any detrimental or ameliorating impact of this effect on pregnancy rates have not been seen. The E2 level decrement or increment following coasting treatment seems not to be related to cycle outcomes.

In vitro maturation: Clinical applications

Oocyte in vitro maturation (IVM) is an assisted reproductive technology in which oocytes are retrieved from the antral follicles of unstimulated or minimally stimulated ovaries. IVM of human oocytes has emerged as a promising procedure. This new technology has advantages over controlled ovarian stimulation such as reduction of costs, simplicity, and elimination of ovarian hyperstimulation syndrome. By elimination or reduction of gonadotropin stimulation, IVM offers eligible infertile couples a safe and convenient form of treatment, and IVM outcomes are currently comparable in safety and efficacy to those of conventional in vitro fertilization. IVM has been applied mainly in patients with polycystic ovary syndrome or ultrasound-only polycystic ovaries, but with time, the indications for IVM have expanded to other uncommon situations such as fertility preservation, as well as to normal responders. In this review, the current clinical experiences with IVM will be described.

Combination of cabergoline and embryo cryopreservation after GnRH agonist triggering prevents OHSS in patients with extremely high estradiol levels--a retrospective study

PURPOSE

Embryo cryopreservation after triggering oocyte maturation with GnRH agonist (GnRHa) in GnRH antagonist protocols has been proposed to prevent ovarian hyperstimulation syndrome (OHSS). However, a small percentage of patients still developed severe OHSS. The purpose of the study was to investigate the efficacy of preventing OHSS in patients at very high risk when cabergoline was given in addition to elective cryopreservation after GnRHa triggering.

METHODS

This is a retrospective observational study. The patients were stimulated with GnRH antagonist protocol. When serum E2 concentration was >6,000 pg/ml and there were more than 20 follicles ≥11 mm on the day of final oocyte maturation, GnRHa was used to trigger oocyte maturation. Cabergoline was given to augment the effect of preventing OHSS. The embryos were electively cryopreserved by vitrification and thawed in subsequent cycles. The primary outcome measure was the incidence of severe OHSS. The secondary outcome measure was the clinical pregnancy rate in the first frozen-thawed embryo transfer cycle.

RESULTS

One hundred and ten patients underwent 110 stimulated cycles were included for analysis. No patients developed moderate/severe OHSS. Mean E2 concentration on the day of final oocyte maturation was 7,873 pg/ml, and an average of 22.7 oocytes was obtained from each patient. One hundred and ten thawing cycles were performed, resulting in 69 clinical pregnancies (62.7 %).

CONCLUSIONS

Combining cabergoline and embryo cryopreservation after GnRHa triggering in GnRH antagonist protocol could prevent OHSS in patients at very high risk.

GnRH analogues in the prevention of ovarian hyperstimulation syndrome

The GnRH analogue (agonist and antagonist GnRH) changed ovarian stimulation. On the one hand, it improved chances of pregnancy to obtain more oocytes and better embryos. This leads to an ovarian hyper-response, which can be complicated by the ovarian hyperstimulation syndrome (OHSS). On the other hand, the GnRH analogue can prevent the incidence of OHSS: GnRH antagonist protocols, GnRH agonist for triggering final oocyte maturation, either together or separately, coasting, and the GnRH analogue may prove useful for avoiding OHSS in high-risk patients. We review these topics in this article.

Comparison of follicular fluid and serum levels of Inhibin A and Inhibin B with calculated indices used as predictive markers of Ovarian Hyperstimulation Syndrome in IVF patients

BACKGROUND

Ovarian Hyperstimulation Syndrome (OHSS) is a severe health complication observed in some patients undergoing hormonal stimulation during IVF. Presence of OHSS is often associated with a high count of growing follicles responding to FSH hyperstimulation. However, the number of responding follicles may not be sufficient enough to predict the onset and severity of OHSS. The aim of this study was to find whether follicular fluid (FF) and serum concentrations of Inhibin A and Inhibin B in patients undergoing IVF treatment may serve as a predictor of OHSS status independent of the growing follicles count.

METHODS

Serum and follicular fluid of fifty-three women undertaking the IVF program were separated into four groups according to their OHSS status and growing follicles count and analyzed for serum and FF concentrations of Inhibin A and Inhibin B. The resulting data were combined with clinical and demographic data to calculate indices independent of the growing follicles count.

RESULTS

Serum Inhibin A and Inhibin B concentrations showed no significant difference between the severe OHSS group and the control group without OHSS. Moreover, the serum concentrations of Inhibin A and Inhibin B were strongly correlated with the growing follicles count. Their concentrations in the high responders group (>18 follicles) were significantly higher (p < 0.00001, p < 0.0001) when compared with normal and low responders (<18 follicles). To suppress the dependence on the growing follicle count, three indices were constructed and calculated. The best association with OHSS status and independence of the growing follicle count was achieved by using the Inhibin B TFF/SBM index calculated as follows: [concentration in FF] x [growing follicle count]/[concentration in serum] x [body mass]. The Inhibin B TFF/SBM index showed a clear difference (p = 0,00433) between the group with severe OHSS and the control group, while showing no apparent correlation with the growing follicle count.

CONCLUSION

These observations demonstrated that while neither serum nor FF concentrations of Inhibin A nor Inhibin B can be used as an OHSS predictor independent of the growing follicle count, calculated indices may meet the criteria.

Review of the evidence base of strategies to prevent ovarian hyperstimulation syndrome

The English-language literature was reviewed to examine the evidence base for strategies that have been used to prevent ovarian hyperstimulation syndrome (OHSS). Prediction of OHSS by pretreatment patient characteristics and ovarian response parameters is unreliable, with a significant number of OHSS cases occurring in patients not thought to be high risk, while the majority of 'high-risk' cycles do not result in OHSS. Alternatives to ovarian stimulation should always be considered, depending on the clinical situation. Monofollicular ovulation induction with a cautious step-up regime carries a lower risk of overstimulation than step-down regimes. In in vitro fertilization (IVF) cycles, a low starting dose of follicle-stimulating hormone (FSH) and the use of 5000 iu human chorionic gonadotrophin (hCG) for final follicular maturation may benefit patients at high risk of OHSS. The role of GnRH antagonists is unclear. In women with polycystic ovaries, who are undergoing ovarian stimulation for IVF, metformin co-treatment may reduce the risk of OHSS. Coasting of cycles with over-response is associated with a reduced risk of OHSS, although precise criteria for initiating and ending coasting are not definable at present. Elective cryopreservation of all embryos prevents late OHSS, but its value has been poorly researched. The literature does not support a role for intravenous albumin, administered around the time of oocyte retrieval, in preventing OHSS. Evidence is insufficient regarding a possible role for hexa-ethyl starch. hCG should not be used for luteal support, as it is associated with a higher risk of OHSS, and equivalent pregnancy rates are obtained with the use of progesterone.

Dual renin-angiotensin blockage and total embryo cryopreservation is not a risk-free strategy in patients at high risk for ovarian hyperstimulation syndrome

OBJECTIVE

To evaluate the effectiveness and safety of dual renin-angiotensin system (RAS) blockage together with total embryo cryopreservation for prevention of ovarian hyperstimulation syndrome (OHSS) in overstimulated patients undergoing IVF.

DESIGN

Retrospective case series.

SETTING

A private tertiary care hospital assisted reproduction program.

PATIENT(S)

Ten women at high risk for OHSS (mean E(2) level 9401 +/- 585 pg/mL on the day of hCG administration).

INTERVENTION(S)

Cancellation of ET and dual RAS blockage with an angiotensin receptor blocker (candesartan cilexetil) and an angiotensin-converting enzyme inhibitor (enalapril) starting from day 1 after oocyte retrieval. Embryos were cryopreserved and transferred in subsequent cycles.

MAIN OUTCOME MEASURE(S)

Development of OHSS and pregnancy and live birth rates after frozen-thawed ETs.

RESULT(S)

While eight women did not develop OHSS, two women (20%) developed severe OHSS requiring hospitalization. Subsequent frozen-thawed ETs resulted in an 80% clinical pregnancy rate and 40% live birth rate.

CONCLUSION(S)

Dual RAS blockage with total embryo cryopreservation is a relatively new strategy that was proposed for use in patients at high risk for OHSS. It should be stressed that complete elimination of the syndrome is not possible with this treatment. Subsequent pregnancy rates with the transfer of frozen-thawed embryos are high.

Odds of ovarian hyperstimulation syndrome (OHSS) - time for reassessment

BACKGROUND

Ovarian hyperstimulation syndrome (OHSS) is a potentially life-threatening complication of Assisted Reproductive Technology (ART) treatment. The objective of this study was to assess the odds of OHSS hospital admission in relation to oestradiol levels on day of hCG administration and number of oocytes collected.

METHODS

We performed a 24 months retrospective analysis of a cohort of patients receiving ART treatment in a University teaching hospital including all patients requiring admission due to OHSS. Main outcome measures were oestradiol levels, number of oocytes collected and incidence of admission with OHSS.

RESULTS

OHSS requiring admission to hospital occurred in 1.8% of cases. While no patients with an oestradiol level at hCG </=15,000 pmol/L developed OHSS, those with oestradiol levels >/=15,000 pmol/L had different risks of admission according to the number of oocytes collected: those with >30 oocytes were 6.7 times more likely to be admitted that those with <20 oocytes.

CONCLUSIONS

This study identifies an oestradiol level (>/=15,000 pmol/L) and number of oocytes (>/=20) above which the odds of being admitted with OHSS increases significantly. Although OHSS cannot always be prevented, these measurable parameters should be used to allow appropriate counselling and subsequent safe management of ART patients.

Application of GnRH antagonist in combination with clomiphene citrate and hMG for patients with exaggerated ovarian response in previous IVF/ICSI cycles

PURPOSE

To investigate if the combination of clomiphene citrate, hMG, and cetrorelix (CC/hMG/cetrorelix protocol) can be applied to patients who had excessive response to GnRHa long protocol.

METHODS

Fifty patients who coasted and failed to conceive in their first cycles stimulated with GnRHa long protocol were stimulated with CC/hMG/cetrorelix protocol. The peak serum estradiol levels, the need of coasting and prolonged coasting (>/=4 days), and the incidences of OHSS were compared.

RESULTS

The peak estradiol level was significantly lower with CC/hMG/cetrorelix protocol compared to GnRHa long protocol. With CC/hMG/cetrorelix protocol, only four patients (8%) needed coasting and no one coasted >/=4 days. In contrast, in the first cycles, 11 patients (22%) needed coasting >/=4 days. The incidence of moderate OHSS was significantly lower with CC/hMG/cetrorelix protocol.

CONCLUSIONS

The CC/hMG/cetrorelix protocol is an acceptable alternative protocol for patients who had excessive response to GnRHa long protocol.

Prevention and management of ovarian hyperstimulation syndrome

The Ovarian Hyperstimulation Syndrome (OHSS) represents one of the biggest nightmares of all physicians involved in Assisted Reproductive Technologies (ART). Every year, several hundreds of women are hospitalized and to date several deaths have been reported. The pivotal event in the development of OHSS is the disruption of capillary integrity that results in leakage of intravascular fluid and proteins into third space. On the molecular level, human chorionic godadotropin (HCG) either exogenous or endogenous, functions as the triggering point for the production of vascular endothelial growth factor (VEGF) that is the main mediator to increase permeability on the vascular bed. Spontaneous OHSS has also been reported, either due to inappropriate activation of a mutant FSH receptor or due to very high levels of HCG during pregnancy. The available evidence on the several preventive and therapeutic approaches with special attention to level 1 evidence when available is also presented. OHSS is a self-resolving condition and the main role of the physician is to correct and maintain the intravascular volume, to support renal function and respiration and prevent thrombotic events. An algorithm on the management of OHSS on an outpatient basis and in the hospital is based on the previous mentioned principles.

The optimal length of 'coasting protocol' in women at risk of ovarian hyperstimulation syndrome undergoing in vitro fertilization

Ovarian hyperstimulation syndrome (OHSS) is a serious and potentially life-threatening complication following ovarian stimulation for in vitro fertilization (IVF). Coasting is the practice whereby the gonadotrophins are withheld and the administration of human chorionic gonadotrophin (hCG) is delayed until serum oestradiol (E2) has decreased to what is considered to be a safe level, to prevent the onset of OHSS. This study aimed to assess the length of coasting on the reproductive outcome in women at risk of developing OHSS. Coasting was undertaken when the serum E2 concentrations were > or = 17000 pmol/L but < 21000 pmol/L. Daily E2 measurements were performed and hCG was administered when hormone levels decreased to < 17000 pmol/L. Eighty-one women who had their stimulation cycles coasted were grouped according to the number of coasting days. Severe OHSS occurred in one case, which represented 1.2% of patients who underwent coasting because of an increased risk of developing the syndrome. No difference was found between cycles coasted for 1 - 3 days and cycles coasted for > or = 4 days in terms of oocyte maturity, fertilization and embryo cleavage rates. Women in whom coasting lasted for > or = 4 days had significantly fewer oocytes retrieved (P < 0.05) and decreased implantation rate (P < 0.05) compared to those coasted for 1 - 3 days. Pregnancy rate/embryo transfer and live birth rate did not differ between groups. In conclusion, coasting appears to decrease the risk of OHSS without compromising the IVF cycle pregnancy outcome. Prolonged coasting is, however, associated with reduced implantation rates, perhaps due to the deleterious effects on the endometrium rather than the oocytes.

The effect of withholding gonadotropin (a coasting period) on the outcome of in vitro fertilization cycles

OBJECTIVE

The purpose of this study was to evaluate the effects of coasting (withdrawing gonadotropin administration) on the cycle outcomes, including total number and quality of oocytes and embryos and pregnancy rate in patients undergoing in vitro fertilization.

STUDY DESIGN

Sixty-seven patients undergoing coasting were evaluated in a retrospective study at the Royan Institute between May 2002 and June 2003. All patients underwent standard long protocol with gonadotropin-releasing hormone (GnRH) analogue and human menopausal gonadotropin (HMG) and then in vitro fertilization and embryo transfer (IVF-ET). Coasting was considered when the estradiol level was more than 3000 pg/ml and the number of follicles >10 in each ovary. HCG was administered whenever estradiol reached < or =3000 pg/ml and then the (IVF-ET) program was carried out. According to coasting periods, patients were divided into two groups: coasting period < or =3 days and coasting period >3 days. Statistical comparisons were performed using Student's t test and Fisher's exact test.

RESULTS

There were no significant differences between the two groups with regard to mean age, body mass index (BMI), number of polycystic ovary syndrome (PCOS) patients, number of HMG ampoules and stimulation duration. The total number of retrieved oocytes decreased significantly in patients with more than 3 days of coasting (P=0.04). The number of high quality oocytes also decreased in this group; however, this did not reach significant levels. There were no significant differences between the two groups with regard to fertilization and pregnancy rate. None of the patients developed severe ovarian hyperstimulation syndrome (OHSS).

CONCLUSION

This study reveals that a long coasting period (>3 days) has a negative effect on the number of oocytes, although the fertilization and pregnancy rates are not affected. Prospective randomized studies with larger sample sizes are needed to compare coasting with other procedures.

Among patients treated for IVF with gonadotrophins and GnRH analogues, is the probability of live birth dependent on the type of analogue used? A systematic review and meta-analysis

This systematic review and meta-analysis aimed to answer the following clinical question: among patients treated for IVF with gonadotrophins and GnRH analogues, is the probability of live birth per randomized patient dependent on the type of analogue used? Eligible studies were randomized controlled trials (RCTs), published as a full manuscript in a peer-reviewed journal, that contained sufficient information to allow ascertainment of whether randomization was true and whether equality was present between the groups compared. A literature search identified 22 RCTs comparing GnRH antagonists and GnRH agonists that involved 3176 subjects. Where live birth was not reported in a study that fulfilled the inclusion criteria, an effort was made to contact the corresponding authors to retrieve the missing information. If this was not possible, the reported outcome measure, clinical pregnancy or ongoing pregnancy was converted to live birth in 12 studies using published data (Arce et al., 2005). No significant difference was present in the probability of live birth between the two GnRH analogues [odds ratio (OR), 0.86; 95% confidence intervals (CI), 0.72 to 1.02]. This result remains stable in subgroup analysis that ordered the studies by type of population studied, gonadotrophin type used for stimulation, type of agonist protocol used, type of agonist used, type of antagonist protocol used, type of antagonist used, presence of allocation concealment, presence of co-intervention and the way the information on live birth was retrieved. In conclusion, the probability of live birth after ovarian stimulation for IVF does not depend on the type of analogue used for pituitary suppression.

Safety of drugs used in assisted reproduction techniques

Infertility may affect one in six couples; however, the development of the assisted reproduction technique (ART) created the opportunity for a large proportion of the infertile population to bear children. Pharmacological agents are routinely used in ART, and new ones are introduced regularly, with the aim of retrieving multiple oocytes to increase the prospect of pregnancy. The combinations of drugs that are used have specific adverse effects, but it is mostly the combined action of more than one agent that causes the greatest concern. The matter is complicated by the suspicion that some techniques in ART, for example intracytoplasmic sperm injection for severe male infertility problems (including azoospermia), may also contribute to the increase in adverse effects, especially congenital malformation. Gonadotropin releasing hormone (GnRH) agonists are widely used in controlled ovarian hyperstimulation. It may give rise to a short period of estradiol withdrawal symptoms and it may also lead to luteal phase deficiency. Similarly GnRHa antagonists, which have been recently introduced to control ovarian hyperstimulation, can lead to luteal phase deficiency and may cause some local injection site reactions. The more pure form of gonadotropin leads to less local injection site reactions and their main adverse effects are associated with the consequences of multiple ovulations. It has been proposed that gonadotropins may be a factor in the increasing risk of ovarian cancer and possibly breast cancer, but this has not been substantiated. Prion infection is another potential hazard, although no cases have been reported. Ovarian hyperstimulation syndrome is a well recognised complication of controlled ovarian hyperstimulation in ART. It is usually a result of recruitment of a large number of ovarian follicles. Efforts to minimise the incidence of this syndrome and its severity are now well developed. Congenital malformations are another possible adverse effect of fertility drugs, but it is more probable that the increase in congenital abnormality that is reported in ART is because of the population studied, i.e. patients already at high risk of congenital malformation, rather than the fertility drugs used or the technique employed. High order multiple pregnancy and its sequela is a well established complication of controlled ovarian hyperstimulation. This could be a result of multiple ovulations or more than one embryo replacement. Reducing the number of embryos transferred can reduce this more serious adverse effect for expectant mothers and for children conceived from ART.

Impact of coasting in patients undergoing controlled ovarian stimulation with the gonadotropin-releasing hormone antagonist cetrorelix

Coasting is the most popular modality for the prevention of ovarian hyperstimulation syndrome, but this procedure has not been evaluated in patients undergoing controlled ovarian hyperstimulation (COH) with GnRH antagonists. The impact of coasting in a cycle in which GnRH antagonist is used was evaluated in 29 women, and it was found that coasting did not deleteriously affect the outcome in high-responder patients undergoing COH with GnRH antagonists.

Coasting for the prevention of ovarian hyperstimulation syndrome: much ado about nothing?

OBJECTIVE

To review and critique the literature and our own experience regarding coasting as a strategy to prevent ovarian hyperstimulation syndrome (OHSS).

DESIGN

Identification of relevant clinical literature through PubMed and EMBASE databases, as well as the experience of our institution with this approach.

CONCLUSION(S)

Coasting is a rescue procedure that can be avoided by carefully adjusting the gonadotropin dosage. It is a good alternative that can be used to avoid cycle cancellation in extremely high responders to controlled ovarian hyperstimulation, who have a high risk of developing severe OHSS. Even if OHSS develops after coasting, both its incidence and severity will be diminished. Each case should be individually counseled to determine whether the patient should be coasted, and her hypothetical risks and benefits should be evaluated. Until the multifactorial etiopathogenesis of OHSS is completely understood, absolute prevention will not be possible, but coasting is definitely of great benefit.

Follicular aspiration during the selection phase prevents severe ovarian hyperstimulation in patients with polycystic ovary syndrome who are undergoing in vitro fertilization

OBJECTIVE

The objective was to assess the effectiveness of follicular aspiration in the selection phase of infertile women with polycystic ovary syndrome (PCOS) under controlled ovarian hyperstimulation (COH).

STUDY DESIGN

In group A, 13 infertile patients with PCOS failed at previous IVF or intracytoplasmic sperm injection (ICSI) treatment due to ovarian hyperstimulation syndrome (OHSS; a total of 13 cycles). In group B, new IVF cycles with ultrasound-guided transvaginal follicular aspirations during the selection phase (a total of 13 cycles) were conducted using the same patients. No more than ten follicles remained in bilateral ovaries. Parameters monitored included ovarian size, number of dominant follicles, estradiol (E2) level on the day of human chorionic gonadotrophin (HCG) injection, maturation of oocytes, fertilization rate, cleavage rate, embryo implantation rate, pregnancy rate, and level of serum hormone.

RESULTS

In group B, the average number of follicles>or=12 mm and average serum E2 level were 15.5+/-4.0 and 9899+/-1430 pmol/l, respectively, which were significantly lower than 29.1+/-8.4 (P<0.001) and 15,544+/-1766 pmol/l (P<0.001) in group A. No cycles with moderate or severe OHSS occurred in group B, while nine out of 13 (69.2%) cycles did have this problem in group A. Oocyte maturation rate, fertilization rate and cleavage rate in group B were 80.7%, 76.9%, and 80.3%, respectively; and all of them are significantly higher than 56.4% (P<0.01), 58.7% (P<0.01), and 70.2% (P<0.02) respectively in group A.

CONCLUSION

Follicular aspiration during the selection phase can prevent severe OHSS and reduce OHSS prevalence in patients with PCOS undergoing COH.

Criteria of a successful coasting protocol for the prevention of severe ovarian hyperstimulation syndrome

BACKGROUND

The aim of this study is to report a large series of patients (n = 1223) at risk of developing ovarian hyperstimulation syndrome (OHSS) who underwent coasting.

METHODS

Coasting started when the leading follicle reached 16 mm and continued until the estradiol (E2) level fell to 3000 pg/ml.

RESULTS

The E2 level at the start of coasting was (mean +/ SD) 6408 +/- 446 and it fell to 2755 +/- 650 on the day of HCG injection, after (mean +/- SD) 2.89 +/- 0.94 days. The results were analysed according to the duration of coasting (< or = 3 days, group I: n = 983; >3 days, group II: n = 240). The number of oocytes retrieved was (mean SD) 16.45 +/- 6.25 and 14.93 +/- 6.01 in groups I and II respectively (P < 0.05). The fertilization rates were 63 and 65% in groups I and II respectively (P > 0.05). The implantation and clinical pregnancy rates were 26 and 52% in group I compared to 18 and 36% in group II respectively (P < 0.05). Severe OHSS occurred in 16 cases, which represented 0.13% of all stimulated cycles, and 1.3% of patients who were at risk of developing OHSS.

CONCLUSIONS

Our protocol of coasting was an effective measure in the prevention of OHSS, without jeopardizing the ICSI outcome. Coasting for >3 days is associated with a moderate decrease in the pregnancy rate.

Effects of coasting on the outcome of intracytoplasmic sperm injection-embryo transfer cycles

OBJECTIVES

To determine the effects of 'coasting' on the outcome of controlled ovarian hyperstimulation (COH) and intracytoplasmic sperm injection-embryo transfer (ICSI-ET).

DESIGN

Retrospective study.

SETTING

IVF Centre, Ozel Ege Tup Bebek Merkezi, Izmir, Turkey.

SAMPLE

Twenty-six coasted and 52 non-coasted COH and ICSI-ET patients were enrolled in this retrospective study.

METHODS

Coasted patients were enrolled consecutively during the study period, and two non-coasted controls were selected from our database for each coasted patient. Coasting was decided when serum oestradiol level was > or = 4000 pg/mL. Groups were compared using chi2 and Mann-Whitney U-tests for statistical analysis.

MAIN OUTCOME MEASURES

Number of oocytes collected, metaphase II (MII) oocytes and cleaving embryos, the fertilisation rate and clinical pregnancy rate were the main outcome measures.

RESULTS

Number of oocytes collected, number of MII oocytes, number of cleaving embryos, fertilisation rate and clinical pregnancy rate for the coasted and non-coasted groups were 15.5 +/- 5.2 and 14.0 +/- 7.1, 9.7 +/- 4.8 and 9.3 +/- 3.9, 6.8 +/- 3.9 and 5.8 +/- 3.1, 0.85 +/- 0.18 and 0.78 +/- 0.18, 13/26 and 24/52, respectively; these differences were not statistically significant. None of the patients in the coasted group were hospitalised for signs or findings of severe ovarian hyperstimulation syndrome.

CONCLUSIONS

Coasting does not adversely affect the number and the function of mature oocytes and the clinical pregnancy rate.

Predictors of success during the coasting period in high-responder patients undergoing controlled ovarian stimulation for assisted conception

OBJECTIVE

To determine the prognostic factors analyzed during the coasting period that can be used to predict outcomes of IVF cycles.

DESIGN

Retrospective review of data from a single center.

SETTING

Referral private IVF center.

PATIENT(S)

Three hundred forty-six patients who were coasted for the prevention of ovarian hyperstimulation syndrome (OHSS) and 262 patients who were not coasted but having excessive E(2) levels during controlled ovarian hyperstimulation for assisted conception.

INTERVENTION(S)

Controlled ovarian hyperstimulation, oocyte retrieval, intracytoplasmic sperm injection, and embryo transfer.

MAIN OUTCOME MEASURE(S)

Number of total oocytes retrieved, oocyte maturity, fertilization, implantation and pregnancy rates (IR and PR, respectively), and incidence of severe OHSS.

RESULT(S)

No difference was found between early onset coasted patients, late onset coasted patients, and uncoasted patients in terms of fertilization rates, IR, PR, and incidence of severe OHSS. Fertilization and PR did not correlate significantly with decreases in E(2) level during the coasting period. Implantation rates and PR in patients who were coasted > or =4 days were significantly reduced compared with patients who were coasted for 1-3 days. In logistic regression model, the decrease in PR with prolonged coasting was found to be significant; however, there was no correlation between decreased PR and the decrease in E(2) levels during the coasting period.

CONCLUSION(S)

Coasting can be applied safely to controlled hyperstimulation cycles without compromising the outcome. The duration of coasting seems to be a prognostic factor for the outcome of IVF. The criteria for initiation of coasting should be based on clinical experience and assessment of the patient.

Cumulative first live birth after elective cryopreservation of all embryos due to ovarian hyperresponsiveness

OBJECTIVE

To estimate cumulative chance for first live birth after elective pronuclear stage cryopreservation of all embryos due to ovarian hyperresponsiveness.

DESIGN

Retrospective analysis with longitudinal follow-up.

SETTING

Academic hospital.

PATIENT(S)

Thirty subjects with elective cryopreservation of all embryos due to ovarian hyperresponsiveness.

INTERVENTION(S)

Elective cryopreservation of all embryos at the pronuclear stage (n = 30) and subsequent cryopreserved-thawed ET (n = 51).

MAIN OUTCOME MEASURE(S)

Cumulative chance for first live birth.

RESULT(S)

Cumulative chance for first live birth was 77% when analyzed by intention to treat and 82% by treatment with ET. Nearly 40% of live births were multiple.

CONCLUSION(S)

Cumulative first live birth increased with repetitive ET after elective pronuclear stage cryopreservation of all embryos due to ovarian hyperresponsiveness. Multiple births, however, were frequent. In the context of initial ET attempts in young women, transfer of no more than two cryopreserved-thawed embryos is advised.

Comparison of coasting and intravenous albumin in the prevention of ovarian hyperstimulation syndrome

OBJECTIVE

To compare the efficacy of coasting to prevent ovarian hyperstimulation syndrome (OHSS) with i.v. albumin and to determine if different timing of gonadotropin coasting would affect the IVF outcomes.

DESIGN

Retrospective study.

SETTING

University hospital-based IVF program.

PATIENT(S)

One hundred sixty-two women undergoing IVF treatment cycles who were considered to be at high risk for developing OHSS.

INTERVENTION(S)

Gonadotropin administration was withheld in 60 patients: either coasting occurred before follicular maturation (early coasting subset, n = 28) or follicular maturity was attained before coasting (late coasting subset, n = 32). Outcomes were compared in 102 patients at risk for OHSS who received i.v. albumin on the day of oocyte retrieval.

MAIN OUTCOME MEASURE(S)

Incidence of OHSS and outcome parameters.

RESULT(S)

Although the fertilization rates and the incidence of OHSS did not differ significantly between the coasting and i.v. albumin groups, the mean number of oocytes retrieved, the pregnancy rates, and implantation rates were significantly lower in the coasting group. There is no statistical difference in the entire outcome examined and the incidence of OHSS between the early and late coasting subsets.

CONCLUSION(S)

Coasting is as effective as i.v. albumin in preventing OHSS in high-risk patients but yields inferior pregnancy rates. Early coasting is as successful as late coasting in preventing OHSS with similar IVF outcome.

Estradiol level on day 9 as a predictor of risk for ovarian hyperresponse during controlled ovarian hyperstimulation

PURPOSE

To investigate the estradiol (E2) level in the mid-follicular phase during controlled ovarian hyperstimulation (COH) and evaluate it as a predictor of a high risk for ovarian hyperresponse.

METHODS

From January 1996 to October 2001, the records of a total of 146 patients undergoing 164 COH cycles were retrospectively reviewed. All patients received the long protocol of GnRH agonists from the previous mid-luteal phase and then hMG or FSH from day 3 of the menstrual cycle. The E2 level was evaluated on day 9. Ovarian hyperresponse was defined as 1) an E2 level on the day of hCG injection was > 4000 pg/mL, or 2) the necessity for coasting during COH to decrease the risk of ovarian hyperstimulation syndrome (OHSS).

RESULTS

Of the 52 cycles in which day 9 E2 level was > 800 pg/mL, 29 (55.8%) fulfilled the criteria for ovarian hyperresponse. None of patients whose day 9 E2 level was < 300 pg/mL met the criteria for hyperresponse. The pregnancy rate in the groups with day 9 E2 level < 300 pg/mL was 42.9%; for an E2 level = 300-800 pg/mL, 49.2%; and for an E2 level > 800 pg/mL, 32.7%. The corresponding implantation rates were 18.8,28.0, and 17.0%. The E2 level on day 9 did not correlate with clinical pregnancy rates or implantation rates.

CONCLUSIONS

A high E2 level in the mid-follicular phase was predictive of patients with a high ovarian response. An E2 level on day 9 of menstrual cycle of > 800 pg/mL suggests an increased risk for ovarian hyperresponse, and appropriate management should be instituted to decrease the risk of OHSS.

Prevention and treatment of ovarian hyperstimulation syndrome

The ovarian hyperstimulation syndrome (OHSS) is a potentially fatal condition with a pathophysiology that is not clearly understood. A shift in fluid from the extravascular space occurs, thought to be induced by cytokines and/or vascular endothelial growth factor. Human chorionic gonadotrophin (hCG), exogenous or endogenous, seems to be the triggering mechanism, resulting in early and late development of the syndrome, respectively. The management of the syndrome is mainly symptomatic. Preventive strategies are being developed and constantly refined. Women at increased risk of OHSS need to be on the lowest possible dose of gonadotrophin with the aim of reducing the granulosa/luteal cell mass. Ultrasound and serum oestradiol (E2) measurements are, at present, the main methods used to identify and monitor those at risk during controlled ovarian hyperstimulation (COH). Withholding gonadotrophin stimulation (coasting), but continuing down-regulation, when a large number of follicles (greater than 20) and a rising serum oestradiol level are seen, is the most widely favoured and used preventive measure and the most cost effective. Management is symptomatic and aimed at achieving fluid balance, restoring plasma volume and improving renal function. This may be combined with an early resort to ascitic fluid aspiration, which will improve the feeling of wellbeing and may remove those agents responsible for the syndrome. Heparin, to prevent the risk of thromboembolism as a result of haemoconcentration, is important.