Decreased incidence of severe ovarian hyperstimulation syndrome in high risk in-vitro fertilization patients receiving intravenous albumin: a prospective study

Prevention of moderate and severe ovarian hyperstimulation syndrome: a guideline

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

Comparison of the Effectiveness of Various Medicines in the Prevention of Ovarian Hyperstimulation Syndrome: A Network Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Previous studies have described the effects of different drugs in preventing ovarian hyperstimulation syndrome (OHSS). However, the efficacies of those drugs in preventing OHSS remain inconclusive.

METHODS

We searched the PubMed, Web of Science, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) databases. A network meta-analysis of randomized controlled trials (RCTs) was performed up to August 2021. We investigated the following drugs in our study: aspirin, albumin, metformin, calcium, cabergoline, quinagolide, letrozole, hydroxyethyl starch (HES), and glucocorticoids. The primary outcome was the incidence rate of moderate-to-severe OHSS, with the results presented as risk ratios (RRs) with 95% confidence intervals (CIs).

RESULTS

The incidence of moderate-to-severe OHSS was significantly reduced by calcium administration (risk ratios [RR] 0.14, 95% confidence interval [CI]: 0.04, 0.46) (grade: high), HES (RR 0.25, 95% CI 0.07, 0.73) (grade: high), and cabergoline (RR 0.43, 95% CI 0.24, 0.71) (grade: moderate). The surface under the cumulative ranking curve (SUCRA) indicated that calcium (SUCRA, 92.4%) was the most effective intervention for preventing moderate-to-severe OHSS. These drugs were safe and did not affect clinical pregnancy, miscarriage, or live birth rates.

CONCLUSION

Calcium, HES, and cabergoline could effectively and safely prevent moderate-to-severe OHSS, with calcium as the most effective intervention.

Whether Letrozole could reduce the incidence of early ovary hyperstimulation syndrome after assisted reproductive technology? A systematic review and meta-analysis

Background

Letrozole can significantly decrease the estrogen level, and has been administrated to prevent the incidence of early ovary hyperstimulation syndrome (OHSS). However, the effect of Letrozole on prevention of OHSS reached to controversial conclusions. The present meta-analysis aim to examine whether Letrozole could reduce the incidence of early OHSS after assisted reproductive technology (ART).

Methods

An exhaustive electronic literature search was conducted on MEDLINE, Google Scholar, CNKI and WANFANG MED ONLINE, from inception until May 2018. We include clinical trials that examined the effect of Letrozole on the prevention of early OHSS. The main outcome measures were the incidence of total early OHSS, mild early OHSS, moderate early OHSS, and severe early OHSS.

Results

Eight studies included in the review. Of these, five publications evaluated the effect of Letrozolel on the prevention of total, mild, moderate, and severe OHSS, respectively. The results indicated that there was a significantly decreased incidence of total OHSS with Letrozole compared with control group, and there were no significantly differences in the incidence of mild, moderate, and severe OHSS between study group with Letrozole and control group. Eight studies reported the incidence of moderate + severe OHSS. We found a significant decrease in incidence of moderate + severe OHSS in high-risk women with Letrozole.

Conclusions

Letrozole has no beneficial effect on the prevention of mild, moderate, and severe OHSS, individually; Letrozole should not be considered as the first-line treatment for prevention of OHSS. Further cohort studies are required to explore the effect of Letrozole on the prevention of OHSS.

Plain English Summary

This study aimed to examine whether Letrozole could reduce the incidence of early OHSS after assisted reproductive technology (ART). A meta-analysis including 8 studies was conducted. There were no significantly differences in the incidence of mild, moderate, and severe OHSS between study group with Letrozole and control group. Letrozole has no beneficial effect on the prevention of mild, moderate, and severe OHSS, individually.

Prevention and treatment of moderate and severe ovarian hyperstimulation syndrome: a guideline

Ovarian hyperstimulation syndrome (OHSS) is an uncommon but serious complication associated with assisted reproductive technology (ART). This systematic review aims to identify who is at high risk, how to prevent OHSS, and the treatment for existing OHSS.

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.

Pharmacologic Interventions in Preventing Ovarian Hyperstimulation Syndrome: A Systematic Review and Network Meta-Analysis

Ovarian hyperstimulation syndrome (OHSS) is a severe iatrogenic complication of controlled ovarian stimulation. Randomised controlled trials (RCTs) have proven several pharmacologic interventions to be effective in OHSS prevention, but these trials have seldom compared multiple drugs. We identified randomised controlled trials (RCTs) through June 2015 by searching databases and compared 11 intervention strategies in preventing OHSS (primary outcome) and their influence on pregnancy rate (secondary outcome). A network meta-analysis was used to evaluate the relative effectiveness among treatments and to create a rank probability table. Thirty-one RCTs were identified, including 7181 participants. Five pharmacologic interventions were superior to placebo in decreasing OHSS incidence: aspirin [relative risk (RR) 0.07, 95% credible interval (CrI) 0.01-0.30, p < 0.05], intravenous (IV) calcium [RR 0.11, 95% CrI 0.02-0.54, p < 0.05], cabergoline [RR 0.17, 95% CrI 0.06-0.43, p < 0.05], metformin [RR 0.20, 95% CrI 0.07-0.59, p < 0.05] and IV hydroxyethyl starch (HES) [RR 0.26, 95% CrI 0.05-0.99, p < 0.05]. The rank probability demonstrated aspirin (Rank 1: 36%) and IV calcium (Rank 1: 35%) to be the most efficacious. Additionally, albumin might decrease the pregnancy rate when compared with placebo [RR 0.85, 95% CI 0.74-0.97, p < 0.05]. This conclusion provides a relative standard and objective reference for choosing an OHSS prophylactic agent.

Ovarian hyperstimulation syndrome: pathophysiology, staging, prediction and prevention

OBJECTIVE

To identify, appraise and summarize the current evidence regarding the pathophysiology, staging, prediction and prevention of ovarian hyperstimulation syndrome (OHSS).

METHODS

Two comprehensive systematic reviews were carried out: one examined methods of predicting either high ovarian response or OHSS and the other examined interventions aimed at reducing the occurrence of OHSS. Additionally, we describe the related pathophysiology and staging criteria.

RESULTS

Seven studies examining methods of predicting OHSS and eight more examining methods of predicting high ovarian response to controlled ovarian stimulation were included. Current evidence shows that the best methods of predicting high response are antral follicle count and anti-Müllerian hormone levels, and that a high ovarian response (examined by the number of large follicles, estradiol concentration or the number of retrieved oocytes) is the best method of predicting the occurrence of OHSS. Ninety-seven randomized controlled trials examining the effect of several interventions for reducing the occurrence of OHSS were included. There was high-quality evidence that replacing human chorionic gonadotropin by gonadotropin-releasing hormone agonists or recombinant luteinizing hormone, and moderate-quality evidence that antagonist protocols, dopamine agonists and mild stimulation, reduce the occurrence of OHSS. The evidence for the effect of the other interventions was of low/very low quality. Additionally, we identified and described 12 different staging criteria.

CONCLUSIONS

There are useful predictive tools and several preventive interventions aimed at reducing the occurrence of OHSS. Acknowledging and understanding them are of crucial importance for planning the treatment of, and, ultimately, eliminating, OHSS while maintaining high pregnancy rates.

Intra-venous fluids for the prevention of severe 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 intravenous fluids such as albumin, hydroxyethyl starch, Haemaccel® and dextran as a possible way for preventing the severe form of OHSS.

OBJECTIVES

To review the effectiveness and safety of administration of intravenous fluids such as albumin, hydroxyethyl starch, Haemaccel® and dextran in the prevention of severe ovarian hyperstimulation syndrome (OHSS) in IVF or ICSI treatment cycles.

SEARCH STRATEGY

We searched the Cochrane Menstrual Disorders and Subfertility Group Specialised Register of controlled trials, the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, to third quarter 2010), MEDLINE (1950 to November 2010), EMBASE (1980 to November 2010) and The National Research Register (to November 2010). The citation lists of relevant publications, review articles, abstracts of scientific meetings and included studies were also searched. The authors were contacted to provide or clarify data that were unclear from the trial reports.

SELECTION CRITERIA

Randomised controlled trials (RCTs) which compared the effects of intravenous fluids with placebo or no treatment for the prevention of severe OHSS in high risk women undergoing IVF or ICSI treatment cycles.

DATA COLLECTION AND ANALYSIS

Two review authors independently scanned the abstracts, identified relevant papers, assessed inclusion of trials and trial quality and extracted relevant data. Validity was assessed in terms of method of randomisation, allocation concealment and outcomes. Where possible, data were pooled for analysis. A separate analysis of studies was performed for human albumin and hydroxyethyl starch versus placebo or no treatment. Other potential intravenous fluids have been identified, such as Haemaccel and dextran, however no randomised controlled studies on their applicability could be found.

MAIN RESULTS

Nine RCTs involving 1660 (human albumin vs placebo) and 487 (HES vs placebo) randomised women, have been included in this review. There was a borderline statistically significant decrease in the incidence of severe OHSS with administration of human albumin (8 RCTs, OR 0.67, 95% CI 0.45 to 0.99).There was a statistically significant decrease in severe OHSS incidence with administration of hydroxyethyl starch (3 RCTs, OR 0.12, 95% CI 0.04 to 0.40). There was no evidence of statistical difference in the pregnancy rate between both groups of treatment.

AUTHORS' CONCLUSIONS

There is limited evidence of benefit from intra-venous albumin administration at the time of oocyte retrieval in the prevention or reduction of the incidence of severe OHSS in high risk women undergoing IVF or ICSI treatment cycles. Hydroxyethyl starch markedly decreases the incidence of severe OHSS.

Does coasting, a procedure to avoid ovarian hyperstimulation syndrome, affect assisted reproduction cycle outcome?

OBJECTIVE

To evaluate the effects of coasting (withdrawing gonadotropin administration) on IVF outcome.

DESIGN

Retrospective study.

SETTING

Department of Infertility of Zekai Tahir Burak Women's Health Research and Education Hospital.

PATIENT(S)

Ninety-four patients in whom coasting was applied (group 1). One control group consisted of 22 patients in whom coasting was not applied despite E(2) > 3000 pg/mL (group 2). A control group consisted of 111 normally responsive patients with peak E(2) < 3000 pg/mL level (group 3).

INTERVENTION(S)

When E(2) levels were greater than 3000 pg/mL in the presence of at least 20 follicles, each measuring >or=10 mm in diameter with >or=20% of them of diameter >or=15 mm, recombinant FSH administration was discontinued while GnRH agonist was maintained.

MAIN OUTCOME MEASURE(S)

Hormonal characteristics, IVF outcome, OHSS in coasted and noncoasted groups.

RESULT(S)

There was no statistically significant difference between number of total oocytes retrieved, metaphase II oocytes, and fertilization rates among the group 1 vs. group 2. However, the implantation rates and pregnancy rates were significantly higher in group 1 compared with group 2. Group 1 had more total oocytes retrieved and metaphase II oocytes compared with group 3. However, there was no significant difference in implantation and pregnancy rates between groups 1 and 3.

CONCLUSION(S)

Coasting does not adversely affect assisted reproductive technology outcome and can be applied safely to high responder patients in ICSI.

Embryo freezing for preventing ovarian hyperstimulation syndrome

BACKGROUND

Ovarian hyperstimulation syndrome (OHSS) is an iatrogenic potentially life threatening condition resulting from an excessive ovarian stimulation. Its reported incidence varies from one percent to ten percent of in vitro fertilization (IVF) cycles. The factors leading to this syndrome have not been completely explained. It seems likely that the release of vasoactive substances, secreted by the ovaries under human chorionic gonadotropin (hCG) stimulation plays a key role in triggering this syndrome. The hallmark of this condition, is a massive shift of fluid from the intra-vascular compartment to the third space resulting in profound intra-vascular depletion and haemoconcentration.

OBJECTIVES

To evaluate (i) the effectiveness of cryopreservation (embryo freezing) for the prevention of OHSS when compared with human intra-venous albumin infusion (ii) the effectiveness of the elective cryopreservation (embryo freezing ) of all embryos for the prevention of OHSS when compared with fresh embryo transfer.

SEARCH STRATEGY

We searched the Cochrane Menstrual Disorders and Subfertility Review Group specialised register of controlled trials up to April 2007. In addition, MEDLINE (PUBMED 1985 to March 2007), EMBASE (1985 to April 2007), CINAHL (1985 to March 2007) and the National Research Register (April 2007) were searched.

SELECTION CRITERIA

Randomised controlled trials (RCTs) in which either human intra-venous albumin or cryopreservation of all embryos were used as a therapeutic approach to OHSS were included. The women were women of reproductive age who were down regulated by gonadotrophin-releasing hormone-analogue (GnRH-a), undergoing superovulation in in vitro fertilization and or intra-cytoplasmic sperm injection (IVF and or ICSI) cycles.

DATA COLLECTION AND ANALYSIS

Two review authors, Mr N.N. Amso (NNA) and Dr A. D'Angelo (ADA) scanned the titles and the abstracts of the reports identified by electronic searching in order to find relevant papers. One reviewer (ADA) obtained copies of the full text articles and made copies for the other reviewer (NNA) in which details of authors, institution, results and discussion were removed in order to assess their eligibility for inclusion . Disagreements were resolved by discussion. Additional information on the trial methodology or data were requested by writing to the corresponding authors directly. The interventions compared were cryopreservation (embryo freezing) versus intra-venous human albumin administration and elective cryopreservation of all embryos versus fresh embryo transfer. The primary outcomes were: incidence of moderate and severe OHSS versus nil and or mild OHSS, clinical pregnancies and or woman. The secondary outcomes were: number of oocytes retrieved, number of oocytes fertilized, number of embryos transferred, number of embryos frozen, multiple pregnancy rate, live birth rate, number of women admitted to the hospital as inpatient or outpatient and time to the next menstrual period (resolution time). Statistical analysis was performed in accordance with the Cochrane Menstrual Disorders and Subfertility Group guidelines.

MAIN RESULTS

No new studies were identified for inclusion in the update therefore the of seventeen studies originally identified in the review published issue 2, 2002. It therefore remains that two studies of which met our inclusion criteria one study was included where cryopreservation (embryo freezing) was compared with intra-venous human albumin administration (Shaker 1996) and one study was included where elective cryopreservation of all embryos was compared with fresh embryo transfer (Ferraretti 1999). When cryopreservation was compared with intra-venous human albumin administration no difference was found in all the outcomes examined between the two groups. When elective cryopreservation of all embryos was compared with fresh embryo transfer no difference was found in all the outcomes examined between the two groups.

AUTHORS' CONCLUSIONS

This updated of the review (D'Angelo 2002) has showed that there is insufficient evidence to support routine cryopreservation and insufficient evidence for the relative merits of intra-venous albumin versus cryopreservation.

Human albumin does not prevent ovarian hyperstimulation syndrome in assisted reproductive technology program: a prospective randomized placebo-controlled double blind study

We aimed to clarify the efficiency of IV human albumin in the prevention of ovarian hyperstimulation syndrome (OHSS). We found that human albumin at the described strength does not seem to either prevent or reduce the incidence of severe OHSS in high risk patients undergoing intracytoplasmic sperm injection (ICSI).

Prevention of severe ovarian hyperstimulation syndrome (OHSS) in IVF patients by steroidal ovarian suppression--a prospective randomized study

Ovarian hyperstimulation syndrome (OHSS) is the major complication associated with artificial reproductive technologies. The aim of this study was to assess the potential of exogenous steroids to prevent OHSS without adversely affecting pregnancy rate. A prospective and randomized study including 945 consecutive cycles in 603 women (mean age 28.6 years) was carried out to evaluate the efficiency of high-dose progesterone and oestradiol administration during the luteal phase to prevent OHSS. After ovulation induction, patients were allocated by a series of computer-generated random numbers to receive either 5000 iu human chorionic gonadotrophin (hCG) 4 and 8 days after embryo transfer (group 1, n = 534) or 500 mg hydroxy-progesterone caproate and 10 mg oestradiol valerate on days 2, 6, 10 and 14 after embryo transfer (group 2, n = 411), by i.m. injection. Total pregnancy rate was 24% (97 of 411) and 23% (121 of 534), and median serum progesterone concentrations on day 15 after embryo transfer were 5.8 ng ml(-1) (range 0.1-298) and 0.1 ng ml(-1) (range 0.1-372) in groups 1 and 2, respectively (P = 0.001). One hundred and sixty-three (30.5%) women in group 1 and 22 (5.4%) women in group 2 developed signs of OHSS (P < 0.0001). These results indicate that steroidal ovarian suppression during the luteal phase is a promising tool to reduce the incidence and severity of OHSS in a high-risk population without compromising the pregnancy rate.

Regulation of matrix metalloproteinase-9 (MMP-9), tissue inhibitor of MMP, and progesterone secretion in luteinized granulosa cells from normally ovulating women with polycystic ovary disease

OBJECTIVE

To investigate the regulation of MMP-9, TIMP-1, and progesterone via three signal transduction pathways in luteinized granulosa cells from normal ovulatory and PCOD women.

DESIGN

In vitro study.

SETTING

Laboratory for Research in Reproductive Sciences, Department of Obstetrics and Gynecology, Ha'Emek Hospital, Afula, Israel.

PATIENT(S)

Ten normal ovulatory and 10 women with polycystic ovary disease (PCOD) treated in an assisted reproduction program.

INTERVENTION(S)

Cultured cells were exposed to phorbol 12-myristate 13-acetate (TPA), acting via protein kinase C (PKC), to epidermal growth factor (EGF), acting via protein tyrosine kinase (PTK), and to forskolin, acting via protein kinase A (PKA).

MAIN OUTCOME MEASURE(S)

Secretion of MMP-9, TIMP-1, and progesterone.

RESULT(S)

Phorbol 12-myristate 13-acetate elicited an increase in MMP-9 and TIMP-1 secretion in both groups and apparently did not affect progesterone secretion. Epidermal growth factor did not change significantly neither MMP-9 nor TIMP-1 secretion but dose dependently decreased MMP-9-TIMP-1 ratio and increased progesterone secretion in the PCOD group. Forskolin inhibited MMP-9 activity and increased TIMP-1 and progesterone secretion in both groups. Progesterone production was inversely related to the ratio of MMP-9-TIMP-1 regardless of cell origin.

CONCLUSION(S)

In this preliminary study, similar and divergent patterns have emerged in the regulation of MMP-9 and TIMP-1 in human luteinized granulosa cells. Repressing MMP-9-TIMP-1 ratio may have an important modulatory effect on progesterone secretion.

Gonadotropin-releasing hormone and reproductive medicine

The hypothalamic gonadotropin-releasing hormone (GnRH) is a key regulator of the reproductive system, mainly through its effects on pituitary luteinizing hormone (LH) and follicle-stimulating hormone (FSH) release. Gonadotropin-releasing hormone analogues are modifications of the natural decapeptide, being either agonists (GnRHa) or antagonists. GnRHa may imitate the native hormone and induce an endogenous LH surge; however, sustained treatment with GnRHa results in complete refractoriness of LH and FSH production. This aspect of GnRHa action is the main application of the GnRHa in reproduction today. The hypogonadotropic hypogonadal state that results from the sustained treatment is the basis for additional applications of the GnRHa. The agonists appear to be effective, to some extent, for the treatment of endometriosis and were proved to be beneficial prior to surgery for fibroma uteri. GnRHa is used in assisted reproduction for both induction of an endogenous LH surge and for induction of ovulation, and its capacity to cause refractoriness of the pituitary may be used to avoid a premature LH surge. It is suggested that the GnRHa have a direct effect on ovarian steroidogenesis, which is independent of its action on the pituitary. This unwanted effect and other possible drawbacks of the agonists are thought to be eliminated with the use of the antagonists. The mechanism of action of these antagonists is through competitive blocking of the GnRH receptor, which results in a rapid but reversible suppression of gonadotropin secretion. As for GnRHa, GnRH antagonists have been proven effective to prevent the LH surge and to reduce the incidence of severe ovarian hyperstimulation syndrome in controlled ovarian stimulation cycles.

Embryo freezing for preventing ovarian hyperstimulation syndrome: a Cochrane review

This paper is based on a Cochrane review published in The Cochrane Library, issue 3, 2002 (see www.CochraneLibrary.net for information) with permission from The Cochrane Collaboration and Update Software. Cochrane reviews are regularly updated as new evidence emerges and in response to comments and criticisms, and The Cochrane Library should be consulted for the most recent version of the review.

BACKGROUND

Ovarian hyperstimulation syndrome (OHSS) is an iatrogenic condition resulting from an excessive ovarian response to superovulation medication. The objective of this review was to evaluate the effectiveness of cryopreservation (embryo freezing) when compared with human i.v. albumin infusion and with fresh embryo transfer for the prevention of OHSS.

METHODS

This was based on a Cochrane Review. Randomized controlled trials in which either human i.v. albumin or cryopreservation of all embryos was used as a therapeutic approach to OHSS were included. The participants were women down-regulated by GnRH agonist, undergoing superovulation in IVF/ICSI cycles. The interventions compared were cryopreservation versus i.v. human albumin administration and elective cryopreservation of all embryos versus fresh embryo transfer. The primary outcomes were: incidence of moderate and severe OHSS versus nil/mild OHSS, and clinical pregnancies/woman. Statistical analysis was performed in accordance with the Cochrane Menstrual Disorders and Subfertility Group guidelines.

RESULTS

Seventeen studies were identified, two of which met our inclusion criteria. One study was included where cryopreservation was compared with i.v. human albumin administration and another where elective cryopreservation of all embryos was compared with fresh embryo transfer. In both interventions no difference was found in all the outcomes examined between the two groups.

CONCLUSIONS

This review has shown that there is insufficient evidence to support routine cryopreservation and insufficient evidence for the relative merits of i.v. albumin versus cryopreservation.

Embryo freezing for preventing Ovarian Hyperstimulation Syndrome

BACKGROUND

Ovarian hyperstimulation syndrome (OHSS) is an iatrogenic potentially life threatening condition resulting from an excessive ovarian stimulation. Its reported incidence varies from 1% to 10% of in vitro fertilization (IVF) cycles. The factors leading to this syndrome have not been completely explained. It seems likely that the release of vasoactive substances, secreted by the ovaries under human chorionic gonadotropin (hCG) stimulation plays a key role in triggering this syndrome. The hallmark of this condition, is a massive shift of fluid from the intra-vascular compartment to the third space resulting in profound intra-vascular depletion and hemoconcentration.

OBJECTIVES

To evaluate (i) the effectiveness of cryopreservation (embryo freezing) for the prevention of OHSS when compared with human intra-venous albumin infusion and (ii) the effectiveness of the elective cryopreservation (embryo freezing ) of all embryos for the prevention of OHSS when compared with fresh embryo transfer.

SEARCH STRATEGY

Publications in the literature that describe or may describe randomised controlled trials of both human intra-venous albumin and freezing of all embryos in the management of OHSS as consequence of the superovulation in assisted reproduction techniques (ART) cycles were searched. The Cochrane Menstrual Disorders and Subfertility Review Group specialised register of controlled trials was searched. In addition, MEDLINE (PUBMED 1985 to 2001), EMBASE (1985 to 2001), CINHAL (1985 to 2001) and the National Research Register were searched

SELECTION CRITERIA

Randomised controlled trials (RCTs) in which either human intra-venous albumin or cryopreservation of all embryos were used as a therapeutic approach to OHSS were included. The participants were women of reproductive age who were down regulated by gonadotrophin-releasing hormone-analogue (GnRH-a), undergoing superovulation in in vitro fertilization/intra-cytoplasmic sperm injection (IVF/ICSI) cycles.

DATA COLLECTION AND ANALYSIS

Two reviewers, Mr N.N. Amso (NNA) and Dr A. D'Angelo (ADA) scanned the titles and the abstracts of the reports identified by electronic searching in order to find relevant papers. One reviewer (ADA) obtained copies of the full text articles and made copies for the other reviewer (NNA) in which details of authors, institution, results and discussion were removed in order to assess their eligibility for inclusion. Then, both reviewers extracted data independently using forms designed according to Cochrane guidelines. Disagreements were resolved by discussion. Additional information on the trial methodology or data were requested by writing to the corresponding authors directly. The interventions compared were cryopreservation (embryo freezing) versus intra-venous human albumin administration and elective cryopreservation of all embryos versus fresh embryo transfer. The primary outcomes were: incidence of moderate and severe OHSS versus nil/mild OHSS, clinical pregnancies/woman. The secondary outcomes were: number of oocytes retrieved, number of oocytes fertilized, number of embryos transferred, number of embryos frozen, multiple pregnancy rate, live birth rate, number of women admitted to the hospital as inpatient or outpatient and time to the next menstrual period (resolution time). Statistical analysis was performed in accordance with the Cochrane Menstrual Disorders and Subfertility Group guidelines.

MAIN RESULTS

Seventeen studies were identified, two of which met our inclusion criteria. One study was included where cryopreservation (embryo freezing) was compared with intra-venous human albumin administration (Shaker 1996) and one study was included where elective cryopreservation of all embryos was compared with fresh embryo transfer (Ferraretti 1999). When cryopreservation was compared with intra-venous human albumin administration no difference was found in all the outcomes examined between the two groups. When elective cryopreservation of all embryos was compared with fresh embryo transfer no difference was found in all the outcomes examined between the two groups.

REVIEWER'S CONCLUSIONS

This review has showed that there is insufficient evidence to support routine cryopreservation and insufficient evidence for the relative merits of intra-venous albumin versus cryopreservation.

Intra-venous albumin for preventing severe ovarian hyperstimulation syndrome

BACKGROUND

Ovarian hyperstimulation syndrome (OHSS) is an iatrogenic condition that occurs after the administration of human menopausal gonadotrophin (hMG) with or without gonadotrophin releasing hormone (GnRH) agonists. OHSS is a threat to every woman undergoing ovulation induction and is potentially lethal in its severest form. Severe OHSS is characterised by growth of multiple large follicles with massive extravascular protein rich fluid shift. This may lead to hypovolaemia, haemoconcentration, oliguria, and electrolyte disturbance. Human albumin solutions are now used in the management of shock and other conditions in which restoration of blood volume is urgent, the acute management of burns, and clinical situations associated with hypoproteinaemia. Recently, a number of clinical trials with conflicting results have been reported in which albumin has been tested as a possible way for preventing the severe form of OHSS.

OBJECTIVES

To review the effectiveness of human albumin administration in prevention of severe ovarian hyperstimulation syndrome.

SEARCH STRATEGY

The Menstrual Disorders and Subfertility Group literature search strategy was used to identify randomised trials that had compared the use of human albumin with placebo or no treatment in the prevention of severe ovarian hyperstimulation syndrome. A diverse search strategy was employed, including handsearching of core journals from 1966 to November 2001, searching bibliographies of relevant trials, MEDLINE, EMBASE, PsychLIT and CINAHL databases, the MDSG specialised register, abstracts from North American and European meetings and contact with authors of relevant papers.

SELECTION CRITERIA

Trials were included if they compared the effect of human albumin with placebo or no treatment on relevant outcomes. Only randomised controlled studies were included in this review.

DATA COLLECTION AND ANALYSIS

Seven randomised controlled trials were identified, five of which met our inclusion criteria and enrolled 378 women (193 in the albumin treated group and 185 in the control group). Trials under consideration were evaluated for methodological quality and appropriateness for inclusion without consideration of their results.The five included trials were single-centre parallel randomised controlled studies. Relevant data were extracted independently by two reviewers using the standardized data extraction sheet. Validity was assessed in terms of method of randomisation, completeness of follow-up, presence or absence of crossover and co-intervention.

DATA SYNTHESIS

2x2 tables were generated for all relevant outcomes. Odds ratios were calculated using the Peto modified Mantel-Haenszel technique.

MAIN RESULTS

Meta-analysis of the five included trials demonstrated significant reduction in severe ovarian hyperstimulation syndrome on administration of human albumin (odds ratio was 0.28 (95% CI 0.11 to 0.73). Relative risk was 0.35 (0.14 - 0.87) and absolute risk reduction was 5.5. For every 18 women at risk of severe OHSS, albumin infusion will save one more case. There was no evidence of an increase in the pregnancy rate (odds ratio was 1.09, (95% CI 0.65 to 1.83) REVIEWER'S CONCLUSIONS: This review shows a clear benefit from administration of intra-venous albumin at the time of oocyte retrieval in prevention of severe OHSS in high-risk cases. Whether the NNT would justify the routine use of albumin infusion in cases at risk of severe OHSS needs to be judged by clinical decision makers.

The questionable use of albumin for the prevention of ovarian hyperstimulation syndrome in an IVF programme: a randomized placebo-controlled trial

BACKGROUND

The role of intravenous (IV) albumin administration in the prevention of ovarian hyperstimulation syndrome (OHSS) and in the improvement of IVF conception outcomes was evaluated in a prospective, randomized, placebo-controlled double blind study.

METHODS

Ninety-eight women were enrolled in the study and were consecutively assigned to either a treatment group or a control group. Eleven patients were lost to follow-up after assignment. Of the remaining 87 women, 46 received albumin on the day of oocyte retrieval, and 41 received 0.9% sodium chloride solution as a placebo control. Outcome measures included OHSS incidence rates and pregnancy rates in the two trial groups.

RESULTS

Four of the 46 patients in the study group developed severe OHSS and six developed moderate OHSS. In the control group, one of the 41 developed severe OHSS and five developed moderate OHSS. The difference in OHSS incidence rates between the two groups was not statistically significant [relative risk (RR) = 1.49, 95% CI = 0.59-3.73]. Fourteen patients (30%) in the intervention group conceived, compared with 16 patients (39%) in the control group. The difference in conception rates between the two groups was not statistically significant (RR = 0.78, 95% CI = 0.44-1.39).

CONCLUSIONS

Albumin appears to have no positive effect on OHSS or conception rates, while its use carries the risk of undesirable side effects, including exacerbation of ascites in OHSS, nausea, vomiting, febrile reaction, allergic reaction, anaphylactic shock and risk of virus and prion transmission. We suggest that this form of treatment should not be included in the prevention of OHSS.

Can we abandon routine evaluation of serum estradiol levels during controlled ovarian hyperstimulation for assisted reproduction?

OBJECTIVE

To assess whether abandoning measurement of serum estradiol (E2) and spacing ultrasound evaluations at greater intervals had an effect on the results of assisted reproduction technology (ART).

DESIGN

A retrospective comparison of two consecutive periods.

SETTING

Division of Assisted Reproduction Technology, Department of Obstetrics and Gynecology, Ha'Emek Medical Center, Afula, Israel.

PATIENT(S)

One thousand nine hundred and eighty-five controlled ovarian hyperstimulation (COH) cycles for ART were initiated during the years 1996 to 1999.

INTERVENTION(S)

During the first 2 years an intensive follow-up protocol was used that included E2 blood levels measurements. In the next 2 years a less intensive protocol was adopted that did not use E2 measurements.

MAIN OUTCOME MEASURE(S)

ART results and the rate of ovarian hyperstimulation syndrome (OHSS).

RESULT(S)

The patients' background characteristics did not differ between the two periods. The cancellation rate was not different (9.8% vs. 7.2%). There was no difference in the duration of stimulation or the amount of gonadotropins used. The number of oocytes retrieved (12.1 +/- 9.3 vs. 9.6 +/- 6.3), fertilization rates (74% vs. 75%), and clinical pregnancy rates (26.2% vs. 27.9%) did not differ. The incidence of severe ovarian hyperstimulation syndrome was not significantly different between the two periods.

CONCLUSION(S)

Controlled ovarian hyperstimulation for ART can be done reliably without routine, serial serum E2 measurements without compromising the treatment results.

Intravenous albumin versus hydroxyethyl starch for the prevention of ovarian hyperstimulation in an in-vitro fertilization programme: a prospective randomized placebo controlled study

A prospective randomized placebo controlled clinical trial was carried out on 250 patients (cycles) considered at risk of developing OHSS in an IVF programme. Criteria for inclusion were: estradiol value of more than 3000 pg/ml or the presence of more than 20 follicles on the day of hCG administration. Patients were randomized by using a random table to receive either 20% human albumin 50 ml (n: 82); 6% hydroxyethyl starch (200/0.5) 500 ml (n: 85) or a placebo of 500 ml 0.9% NaCl solution (n: 83) over 30 min during oocyte collection. Groups were similar with respect to patients' age, estradiol levels on hCG day, body mass index, number of oocytes retrieved, number of embryos transferred and pregnancies (P>0.05). There was no severe OHSS in patients who received albumin and HES while four patients who received placebo developed severe OHSS. On the other hand moderate OHSS was encountered in four patients in the albumin group; five patients receiving HES; and 12 patients receiving placebo. There was a statistically significant difference in the incidence of moderate, severe and overall OHSS among groups (P values of <0.05, <0.05, and <0.01, respectively). Both HES and albumin significantly reduced the incidence of moderate, severe and overall incidence of OHSS. It is concluded that hydroxyethyl starch is a cheaper and safer alternative to Human Albumin in OHSS prevention.

Distinction between early and late ovarian hyperstimulation syndrome

OBJECTIVE

To compare patient and cycle characteristics among three study groups: early ovarian hyperstimulation syndrome (OHSS), late OHSS, and non-OHSS.

DESIGN

Prospective observational study.

SETTING

University assisted conception service.

PATIENT(S)

Women undergoing in vitro fertilization, intracytoplasmic sperm injection or gamete intrafallopian transfer treatment at Bristol University In Vitro Fertilization Service between January 1, 1995, and December 31, 1998.

INTERVENTION

None.

MAIN OUTCOME MEASURE(S)

Patient age, prevalence of polycystic ovaries, gonadotropin requirement, peak serum estradiol (E(2)) concentration, number of oocytes retrieved, clinical pregnancy rate, number of gestation sacs, and severity of OHSS.

RESULT(S)

Women with early OHSS had significantly higher serum E(2) levels and lower gonadotropin requirements than did the other groups. Cycles with either early or late OHSS had significantly more oocytes collected than those without OHSS. Serum E(2) and oocyte numbers did not accurately predict the risk of developing late OHSS. Clinical pregnancies occurred in all cycles with late OHSS, and multiple pregnancies were significantly more frequent in the late OHSS group than in the other groups. Late OHSS was more likely than early OHSS to be severe.

CONCLUSION(S)

Early OHSS relates to "excessive" preovulatory response to stimulation, whereas late OHSS depends on the occurrence of pregnancy, is likelier to be severe, and is only poorly related to preovulatory events.

An ounce of prevention: outpatient management of the ovarian hyperstimulation syndrome

OBJECTIVE

To evaluate a protocol of active outpatient management, including outpatient paracentesis and albumin administration, in women at risk for severe ovarian hyperstimulation syndrome (OHSS).

DESIGN

Prospective cohort.

SETTING

Freestanding IVF program.

PATIENT(S)

Thirteen women progressing from moderate to severe OHSS.

INTERVENTION(S)

Bed rest and home monitoring with intermittent outpatient paracentesis and albumin administration.

MAIN OUTCOME MEASURE(S)

Procedural outcomes and time to resolution of OHSS symptoms.

RESULT(S)

The initial paracentesis occurred 14.1 +/- 3.3 days after oocyte retrieval, removing 1,735 +/- 506 mL of ascitic fluid. Eleven women required a second paracentesis and five women required a third paracentesis over the next 8 days. Six women received albumin on seven occasions because of hypoalbuminemia. The onset of diuresis occurred 2.8 +/- 1.9 days and recovery occurred 7. 4 +/- 3.0 days after the first paracentesis. There were no hospitalizations for OHSS symptoms and no complications. All 13 women had viable intrauterine pregnancies.

CONCLUSION

Active outpatient intervention in the early stages of OHSS, including paracentesis and albumin administration, can avoid hospitalization while minimizing the progression and complications of OHSS.

Prediction of severe ovarian hyperstimulation syndrome by free serum vascular endothelial growth factor concentration on the day of human chorionic gonadotrophin administration

In this prospective study the concentration of circulating vascular endothelial growth factor (VEGF) was followed in 10 patients with severe ovarian hyperstimulation syndrome (OHSS) after ovarian stimulation and in 15 patients without OHSS. VEGF was assayed by means of two different commercially available kits as either free or total VEGF in serum. The concentration of free VEGF was significantly higher on the days of human chorionic gonadotrophin (HCG) administration (309.4 +/- 165.0 versus 190.3 +/- 127.8 pg/ml, P < 0.05) and embryo transfer (315.0 +/- 125.2 versus 209.3 +/- 137. 2 pg/ml, P < 0.05) in the OHSS compared to the control group. No such difference existed with respect to total circulating VEGF. In addition, there was no significant rise in the free or in the total serum VEGF concentration in the OHSS patients or the controls from the day of HCG administration up to the days of oocyte retrieval or embryo transfer. A cut-off concentration of 200 pg/ml free serum VEGF concentration on the day of HCG treatment resulted in a sensitivity of 90% and a specificity of 80% for the prediction of OHSS development. This is the first report on the parallel measurement of free and total VEGF in serum following ovarian stimulation. The value of the proposed cut-off concentration should be confirmed in a study of a larger group of women.

Withholding gonadotropins ("coasting") to minimize the risk of ovarian hyperstimulation during superovulation and in vitro fertilization-embryo transfer cycles

OBJECTIVE

To evaluate superovulation (SOV) and IVF-ET cycles in which E2 levels were allowed to decrease to restrain rapid follicular growth and minimize the risk of ovarian hyperstimulation syndrome.

DESIGN

Retrospective series.

SETTING

Tertiary care infertility practice.

PATIENT(S)

Women who underwent SOV (n = 51) and IVF-ET (n = 93) treatment and who were at risk for OHSS.

INTERVENTION(S)

In SOV cycles, hMG was withheld (coasting) for >3 days before hCG administration, until follicular maturity was attained (> or = 3 follicles of > or = 18 mm) and E2 levels decreased. In IVF-ET cycles, either follicular maturity was attained before coasting (n = 63), allowing hCG administration after E2 levels decreased by >25%, or coasting occurred before follicular maturation (n = 30), necessitating the administration of additional hMG after coasting.

MAIN OUTCOME MEASURE(S)

Estradiol concentrations, follicle size, and pregnancy rates.

RESULT(S)

Estradiol concentrations usually rose for > or = 1 day after coasting began, then fell by > or = 25% while follicle numbers and mean diameters increased. No spontaneous LH surges occurred, although four SOV cycles were canceled because of excessive follicular development. Of the women who received hCG,11 of 47 (23% per cycle) conceived during SOV and 35 of 93 (37.6% per cycle) conceived during IVF-ET. Severe ovarian hyperstimulation syndrome developed in 1 woman who underwent IVF-ET.

CONCLUSION(S)

Coasting can safely rescue overstimulated SOV and IVF-ET cycles characterized by an excessive rise in E2 levels and/or numerous incompletely mature follicles.

Ovarian hyperstimulation syndrome: facts and fallacies

Severe or critical ovarian hyperstimulation syndrome (OHSS) is a serious complication of ovarian hyperstimulation for assisted reproduction techniques (ART). The syndrome is characterized by cystic enlargement of the ovaries and fluid shifts from the intravascular to the third space. The morbidity in OHSS is mainly determined by the hemodynamic changes caused by increased capillary permeability. The incidence of OHSS depends on definitions, risk factors, ovarian stimulation protocols, luteal support and conception. Currently, research on the pathogenesis of OHSS is focused on increased capillary permeability. Several theories are reviewed. Until the pathogenesis of OHSS becomes clear, treatment is restricted to supportive therapy. The various proposals for management of OHSS are discussed and, based on the available data, directions for the management of various grades of OHSS are summarized. However, prevention and early recognition are still the most important tools to handle OHSS. A flowchart with preventive measures for OHSS is presented derived from the available literature.

"Coasting" does not adversely affect cycle outcome in a subset of highly responsive in vitro fertilization patients

OBJECTIVE

To study the effect of postponing hCG administration while continuing daily GnRH agonist therapy ("coasting") on highly responsive patients undergoing IVF-ET.

DESIGN

Retrospective analysis.

SETTING

University-affiliated Center for Fertility and Reproductive Medicine.

PATIENT(S)

Patients undergoing IVF-ET from March 1995 to March 1997.

INTERVENTION(S)

Three groups of IVF-ET patients were compared to explore the effect of coasting on cycle outcome: a group of highly responsive coasted patients, a group of equally responsive noncoasted patients, and an age-matched normally responsive control group. Two groups of coasted patients were also compared to assess the effect of E2 levels at the time that they met the follicular criteria for hCG administration. Last, the effect of varying coast duration was examined by regression analysis.

MAIN OUTCOME MEASURE(S)

Patient characteristics, outcome parameters, and incidence of ovarian hyperstimulation syndrome (OHSS).

RESULT(S)

Coasting had no detrimental effect on cycle outcome in the subset studied. Regression analysis, however, suggests an inverse relationship between coast duration and the number of mature oocytes retrieved as well as the clinical pregnancy rate.

CONCLUSION(S)

Coasting in the studied subset of IVF patients did not adversely affect cycle outcome parameters or the incidence of OHSS, but prolonged coasting intervals may impair IVF cycle outcome.

Intravenous albumin does not prevent the development of severe ovarian hyperstimulation syndrome

OBJECTIVE

To determine the efficacy of IV albumin in the prevention of severe ovarian hyperstimulation syndrome (OHSS).

DESIGN

Prospective study group with historical control.

SETTING

University hospital-based IVF program.

PATIENT(S)

Between 1993 and 1995, 42 consecutive patients undergoing IVF-ET or tubal ET who had serum E2 levels > or = 3,600 pg/mL (conversion factor to SI unit, 3.671) on the day of hCG administration and/or > or = 20 oocytes retrieved were considered at high risk for severe OHSS and were selected as the control group. From December 1995 to October 1996, IV albumin was given to 30 consecutive patients who fulfilled these criteria.

INTERVENTION(S)

The treatment group received IV albumin after oocyte retrieval.

MAIN OUTCOME MEASURE

Occurrence of severe OHSS.

RESULT(S)

None of the 16 patients in the treatment group in nonconception cycles developed severe OHSS, compared with 5 (21.7%) of 23 in the control group. In conception cycles, 4 (28.6%) of 14 patients in the treatment group developed severe OHSS, compared with 9 (47.4%) of 19 in the control group. All 4 patients with multiple pregnancies in the treatment group developed severe OHSS, compared with 3 (60%) of 5 in the control group. None of the 10 patients with singleton pregnancies in the treatment group developed severe OHSS, compared with 6 (42.9%) of 14 in the control group.

CONCLUSION(S)

Intravenous albumin prevents severe OHSS in high-risk patients who did not conceive or who carried singleton pregnancies, but not in the patients with high-order pregnancies.