Plasma estradiol is superior to ultrasound and urinary estriol glucuronide as a predictor of ovarian hyperstimulation during induction of ovulation with menotropins

Treatment of Ovarian Hyperstimulation Syndrome in a Mouse Model by Cannabidiol, an Angiogenesis Pathway Inhibitor

Studies suggest that ovarian hyperstimulation syndrome (OHSS) can be treated by reducing the level of vascular endothelial growth factor (VEGF). However, due to the side effects of commercially available VEGF-reducing drugs, they can be ruled out as a suitable treatment for OHSS; therefore, researchers are looking for new medications to treat OHSS. This study is aimed at investigating the effects of cannabidiol (CBD) in an OHSS model and to evaluate its efficacy in modulating the angiogenesis pathway and VEGF gene expression. For this purpose, 32 female mice were randomly divided into four groups (eight mice per group): control group, group 2 with OHSS induction, group 3 receiving 32 nmol of dimethyl sulfoxide after OHSS induction, and group 4 receiving 30 mg/kg of CBD after OHSS induction. The animals' body weight, ovarian weight, vascular permeability (VP), and ovarian follicle count were measured, and the levels of VEGF gene and protein expression in the peritoneal fluid were assessed. Based on the results, CBD decreased the body and ovarian weights, VP, and corpus luteum number compared to the OHSS group (p < 0.05). The peritoneal VEGF gene and protein expression levels reduced in the CBD group compared to the OHSS group (p < 0.05). Also, CBD caused OHSS alleviation by suppressing VEGF expression and VP. Overall, CBD downregulated VEGF gene expression and improved VP in OHSS.

Lipid Metabolic Disorders and Ovarian Hyperstimulation Syndrome: A Retrospective Analysis

OBJECTIVES

To evaluate the effect of dyslipidemia on the incidence of moderate and severe Ovarian hyperstimulation syndrome (OHSS) in the duration of assisted reproduction technique (ART).

METHODS

The study included 233 moderate and severe OHSS patients who received hospitalization after in-vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) cycles to avoid severe complications. They were divided into dyslipidemia group and normal lipid metabolism group to evaluate whether dyslipidemia contributes to the development of severe OHSS. Subgroup analysis was set to avoid deviation including the freeze-all group and fresh embryo transfer (ET) group according to whether the eligible women chose fresh embryo transfer immediately after their IVF or ICSI cycles. The main outcome measures included the incidence of moderate OHSS and severe OHSS, total gonadotropin dose, number of oocytes retrieved, age and body mass index (BMI). In the ET groups, the rate of pregnancy is also included for analysis.

RESULTS

In the freeze-all group, lipid metabolism was ultimately identified as the factor affecting the morbidity of severe OHSS and the ones with dyslipidemia were more likely to develop to severe OHSS (P < 0.05), while the incidence of severe OHSS among the ET groups had no statistical significance (P > 0.05).

CONCLUSION

The findings of this study suggested that dyslipidemia might contribute to the development of OHSS, especially for those patients who chose the cryopreservation of all embryos. It is essential to consider the risk of OHSS in patients with dyslipidemia although they required cryopreservation of all embryos.

Is thromboprophylaxis cost effective in ovarian hyperstimulation syndrome: A systematic review and cost analysis

BACKGROUND

The majority of serious thromboembolic events occurring in assisted reproductive technologies (ART) are in women with ovarian hyperstimulation syndrome (OHSS).

OBJECTIVES

The purpose of this study was to present a thorough review and cost analysis regarding the use of venous thromboembolism (VTE) prophylaxis in OHSS to inform clinical management.

DATA SOURCES

Databases used were Pubmed and Embase, in addition to checking reference lists of retrieved articles (inception to November 2017).

METHODS

The systematic search strategy identified 365 titles and abstracts. Articles included in the qualitative synthesis had identified venous thrombosis incidence rates or ratios. A separate search for the cost model was conducted recognizing all associated complications of VTE. The decision tree was modeled to best fit the patient population and a sensitivity analysis was performed over a range of variables.

RESULTS

The cost of VTE event per OHSS patient not on prophylaxis was €5940 (range €3405 to €38,727), versus €4134 (€2705 to €23,192) per event per patient on prophylaxis, amounting to a saving of (€19 to €23,192) per VTE per patient. Sensitivity analysis found VTE prophyaxis to be cost effective if the incidence of VTE in the OHSS population was greater than 2.79%. Prophylactic therapy was cost effective through 16 weeks of treatment.

LIMITATIONS

OHSS is infrequent and hence, the incidence of VTE in patients with OHSS is low; therefore, the data used to inform the incidence of VTE in OHSS in the model carry some uncertainty. Further, low molecular weight heparin (LMWH) has side effects therefore individualization of care must be considered.

CONCLUSIONS

With the increasing incidence of infertility and requirement for ART, thromboembolism in OHSS poses a major health threat for patients. VTE prophylaxis using enoxaparin was cost effective in patients with severe OHSS over a wide range of costs and incidences. Prophylaxis was also cost effective through the completion of the first trimester of pregnancy.

Fresh versus Frozen Embryos for Infertility in the Polycystic Ovary Syndrome

BACKGROUND

The transfer of fresh embryos is generally preferred over the transfer of frozen embryos for in vitro fertilization (IVF), but some evidence suggests that frozen-embryo transfer may improve the live-birth rate and lower the rates of the ovarian hyperstimulation syndrome and pregnancy complications in women with the polycystic ovary syndrome.

METHODS

In this multicenter trial, we randomly assigned 1508 infertile women with the polycystic ovary syndrome who were undergoing their first IVF cycle to undergo either fresh-embryo transfer or embryo cryopreservation followed by frozen-embryo transfer. After 3 days of embryo development, women underwent the transfer of up to two fresh or frozen embryos. The primary outcome was a live birth after the first embryo transfer.

RESULTS

Frozen-embryo transfer resulted in a higher frequency of live birth after the first transfer than did fresh-embryo transfer (49.3% vs. 42.0%), for a rate ratio of 1.17 (95% confidence interval [CI], 1.05 to 1.31; P=0.004). Women who underwent frozen-embryo transfer also had a lower frequency of pregnancy loss (22.0% vs. 32.7%), for a rate ratio of 0.67 (95% CI, 0.54 to 0.83; P<0.001), and of the ovarian hyperstimulation syndrome (1.3% vs. 7.1%), for a rate ratio of 0.19 (95% CI, 0.10 to 0.37; P<0.001), but a higher frequency of preeclampsia (4.4% vs. 1.4%), for a rate ratio of 3.12 (95% CI, 1.26 to 7.73; P=0.009). There were no significant between-group differences in rates of other pregnancy and neonatal complications. There were five neonatal deaths in the frozen-embryo group and none in the fresh-embryo group (P=0.06).

CONCLUSIONS

Among infertile women with the polycystic ovary syndrome, frozen-embryo transfer was associated with a higher rate of live birth, a lower risk of the ovarian hyperstimulation syndrome, and a higher risk of preeclampsia after the first transfer than was fresh-embryo transfer. (Funded by the National Basic Research Program of China and others; ClinicalTrials.gov number, NCT01841528.).

GnRH agonist with low-dose hCG (dual trigger) is associated with higher risk of severe ovarian hyperstimulation syndrome compared to GnRH agonist alone

PURPOSE

The purpose of this study was to compare rates of ovarian hyperstimulation syndrome (OHSS) after using gonadotropin-releasing hormone agonists (GnRHa) alone and GnRHa in combination with low-dose human chorionic gonadotropin (hCG, dual trigger) for final oocyte maturation in women undergoing controlled ovarian hyperstimulation (COH).

METHODS

A retrospective cohort study was conducted at an academic center. Study population included 108 women who received GnRHa trigger and 66 women who received dual trigger (GnRHa + low-dose [1000 IU] hCG trigger). The main outcome measure was OHSS. Secondary outcomes included total oocyte yield and oocyte maturity.

RESULTS

The incidence of early OHSS was significantly higher after dual trigger than GnRHa trigger (8.6 vs 0 %). Moreover, four of the six patients that developed OHSS developed severe OHSS. Logistic modeling revealed that the combination of age, BMI, baseline AFC, and E2 >4000 pg/mL was predictive of OHSS with an area under the receiver operating characteristic curve of 0.84 and was superior to each factor alone. Adjusted analyses revealed that dual trigger was associated with a higher number of total oocytes (adjusted OR 1.27; 95 % confidence interval, 1.18, 1.38) and percentage of mature oocytes (AOR 1.10; 95 % confidence interval, 1.03, 1.17) obtained compared to GnRHa trigger alone.

CONCLUSIONS

Dual trigger for final oocyte maturation using GnRHa and low-dose hCG is associated with a significantly increased risk of severe OHSS compared to GnRH alone. However, dual trigger may be associated with a modest increase in oocyte yield, both in terms of number and maturity.

Revisiting ovarian hyper stimulation syndrome: Towards OHSS free clinic

A rapid development and application of assisted reproductive technologies (ARTs) and ovulation-induction drugs may lead to ovarian hyper stimulation syndrome (OHSS). Young age, low body mass index (BMI), polycystic ovarian syndrome (PCOS), previous OHSS, high follicle count, and elevated serum estradiol (E2) are the certain factors that predispose women to OHSS. Many strategies have been used to reduce or avoid OHSS. Use of human chorionic gonadotropin (hCG) increases ovarian vascular permeability and is responsible for activating the vascular endothelial growth factors (VEGF) pathway and thus the entire cascade, leading to symptomatic OHSS. Gonadotropin-releasing hormone (GnRH) agonists are used as a replacement for hCG for final oocyte maturation in antagonist cycles. Reducing or eliminating the use of hCG and use of GnRH agonist triggered GnRH antagonist cycles and cryopreservation of oocytes or embryos is the most promising approach in making OHSS free clinic a reality.

Triggering final oocyte maturation with gonadotropin-releasing hormone agonist (GnRHa) versus human chorionic gonadotropin (hCG) in breast cancer patients undergoing fertility preservation: an extended experience

PURPOSE

To analyze the cycle outcomes and the incidence of ovarian hyperstimulation syndrome (OHSS), when oocyte maturation was triggered by gonadotropin-releasing hormone agonist (GnRHa) versus human chorionic gonadotropin (hCG) in breast cancer patients undergoing fertility preservation.

METHODS

One hundred twenty-nine women aged ≤ 45 years, diagnosed with stage ≤ 3 breast cancer, with normal ovarian reserve who desired fertility preservation were included in the retrospective cohort study. Ovarian stimulation was achieved utilizing letrozole and gonadotropins. Oocyte maturation was triggered with GnRHa or hCG. Baseline AMH levels, number of oocytes, maturation and fertilization rates, number of embryos, and the incidence of OHSS was recorded.

RESULTS

The serum AMH levels were similar between GnRHa and hCG groups (2.7 ± 1.9 vs. 2.1 ± 1.8; p = 0.327). There was one case of mild or moderate OHSS in the GnRHa group compared to 12 in the hCG group (2.1 % vs. 14.4 %, p = 0.032). The maturation and fertilization rates, and the number of cryopreserved embryos were significantly higher in the GnRHa group.

CONCLUSIONS

GnRHa trigger improved cycle outcomes as evidenced by the number of mature oocytes and cryopreserved embryos, while significantly reducing the risk of OHSS in breast cancer patients undergoing fertility preservation.

Cabergoline as treatment of ovarian hyperstimulation syndrome: a review

One of the most serious complications of assisted reproduction techniques is ovarian hyperstimulation syndrome (OHSS). OHSS not only increases morbidity and mortality in IFV cycles, but also causes significant other problems, as cancelled in vitro fertilization (IVF) cycles, prolonged hospitalization, causing emotional and sociofinancial consequences. Several treatments for OHSS have been proposed and among these Cabergoline (Cb2). Despite the above-mentioned beneficial effect, Cb2 has not been widely used in everyday's clinical practice. With our study, we try to review all studies with strong evidence examining Cb2 use for OHSS prevention.

The clinical ramifications of polycystic ovarian morphology in oocyte donors

OBJECTIVE

To determine the relationship between Polycystic Ovary (PCO) morphology and In Vitro Fertilization (IVF) outcome in oocyte donation cycles.

DESIGN

Cross sectional study

SETTING

Private IVF clinic

PATIENTS

164 consecutive ovum donors and their recipients were reviewed, 149 were included in the study where 113 patients had normal ovarian morphology and 36 patients had PCO morphology.

INTERVENTIONS

All donors underwent ovarian stimulation in conjunction with GnRH agonist or antagonist in standard fashion.

MAIN OUTCOME MEASURES

Baseline donor characteristics were recorded, as well as details of IVF stimulation and embryo data. Recipient data on pregnancy and miscarriage were also collected.

RESULTS

Patients with PCO ovaries had significantly higher peak estradiol levels and required less gonadotropins during IVF stimulation. In addition, the baseline characteristics between donor groups did not differ except for ovarian morphology. The number of oocytes retrieved and indicators of embryo quality did not differ between the two groups, and there was no significant difference between pregnancy and miscarriage rates in the recipients.

CONCLUSIONS

Oocyte donors with PCO morphology have equivalent pregnancy rates and do not need to be excluded as potential donors.

[Ovarian hyperstimulation syndrome: pathophysiology, risk factors, prevention, diagnosis and treatment]

The ovarian hyperstimulation syndrome is a major complication of ovulation induction for in vitro fertilization, with severe morbidity and possible mortality. Whereas its pathophysiology remains ill-established, the VEGF may play a key role as well as coagulation disturbances. Risk factors for severe OHSS may be related to patients characteristics or to the management of the ovarian stimulation. Two types of OHSS are usually distinguished: the early OHSS, immediately following the ovulation triggering and a later and more severe one, occurring in case of pregnancy. As no etiologic treatment is available, the therapeutic management of OHSS should focus on its related-complications. Thrombotic complications that can occur in venous or arterial vessels represent the major risk of OHSS, possibly conducting to myocardial infarction and cerebrovascular accidents. Once the OHSS is diagnosed, prevention of thrombotic accidents remains the major issue.

Ovarian hyperstimulation syndrome in a patient treated with tamoxifen for breast cancer

OBJECTIVE

To report the management of a rare case of ovarian hyperstimulation syndrome (OHSS) induced by tamoxifen therapy for breast cancer in a 50-year-old woman.

DESIGN

Case report.

SETTING

Gynecology outpatient department of a university hospital.

PATIENT(S)

A 50-year-old premenopausal patient with a history of breast cancer was prescribed adjuvant treatment with tamoxifen.

INTERVENTION(S)

Temporary discontinuation of tamoxifen therapy resolved symptoms, but resumption of tamoxifen caused a recurrence of symptoms. Surgical bilateral salpingo-oophrectomy was therefore performed.

MAIN OUTCOME MEASURE(S)

Resolution of symptoms of OHSS.

RESULT(S)

Bilateral salpingo-oophrectomy rendered the patient postmenopausal and enabled the commencement of the aromatase inhibitor anastrozole as an alternative adjuvant therapy for breast cancer.

CONCLUSION(S)

Tamoxifen-induced OHSS is rare. Furthermore, OHSS is very rare in the older female. OHSS usually resolves with temporary discontinuation of tamoxifen, however, the recurrence of symptoms when resuming tamoxifen is better treated with bilateral salpingo-oophorectomy to enable adjuvant treatment with anastrazole.

The pathophysiology of ovarian hyperstimulation syndrome: an unrecognized compartment syndrome

OBJECTIVE

To compare and contrast the pathophysiology of ovarian hyperstimualtion syndrome (OHSS) with known syndromes of increased intraabdominal pressure (IAP), and to explore the relationship of increased IAP with symptom severity in OHSS.

DESIGN

Literature review.

MAIN OUTCOME MEASURE(S)

Correlation of OHSS symptoms with IAP; effects of paracentesis on IAP in patients with OHSS.

SETTING

Academic Research Institution.

INTERVENTION(S)

None.

RESULT(S)

OHSS involves a rapid accumulation of volume (from 1.5-17 liters) in the peritoneal cavity that can lead to organ dysfunction, including respiratory impairment and oliguria. In published reports of 20 moderate-to-severe OHSS patients in whom IAP was measured, IAP was found to be elevated to a pathologic range. The increased IAP indicates that OHSS may be considered a compartment syndrome and meets criteria for abdominal compartment syndrome in advanced cases. For this reason, management of OHSS should include reduction of pressure by paracentesis to avoid morbidity and syndrome progression. In addition, measurement of IAP may help to classify the stage of OHSS.

CONCLUSION(S)

IAP was found to be elevated in the few cases of OHSS in which it was measured, substantiating the conclusion that OHSS may be considered a compartment syndrome. An understanding of the pathophysiology of increased intrabdominal pressure is useful in the management of OHSS.

Current status of the approach to assisted reproduction

Assisted reproductive technologies are important tools in the clinical armamentarium used to treat both female and male infertility disorders. Pre-implantation genetic diagnosis offers couples at risk of having children with inheritable disorders the ability to analyze the genetic make-up of embryos before transfer. For patients undergoing treatment of cancer with chemotherapy or radiation therapy, these technologies offer the potential for the preservation of future fertility. As technology evolves, it is likely the clinical applications of assisted reproduction will continue to develop and expand in the future to enhance fertility.

Coasting vs. cryopreservation of all embryos for prevention of ovarian hyperstimulation syndrome in in vitro fertilization

In the patient at risk for ovarian hyperstimulation syndrome, coasting will result in fewer eggs retrieved and embryos produced when compared with cryopreservation of all embryos. However, both strategies are associated with a similar incidence of ovarian hyperstimulation syndrome, with achievement of comparable cumulative pregnancy rates.

Persistent megalocystic ovary following in vitro fertilization in a postpartum patient with polycystic ovarian syndrome

OBJECTIVE

Ovarian hyperstimulation syndrome (OHSS) is more severe when pregnancy occurs, as the developing pregnancy produces human chorionic gonadotropin, which stimulates the ovary's persistent growth. If no pregnancy occurs, the syndrome will typically resolve within 1 week. In a maintained pregnancy, slow resolution of symptoms usually occurs over 1-2 months.

CASE REPORT

A 31-year-old woman, gravida 2, para 1, aborta 1, with polycystic ovary syndrome underwent in vitro fertilization (IVF) with clomiphene citrate and follicle-stimulating hormone/gonadotropin releasing hormone-antagonist stimulation. During transvaginal oocyte retrieval, enlarged bilateral ovaries were noted. She had an episode of OHSS after IVF/embryo transfer, for which paracentesis was performed three times. Pregnancy was achieved. Throughout antenatal examinations, bilateral ovaries were enlarged. She delivered a healthy baby by cesarean section at term. However, 1 month after delivery, the bilateral ovary had not shrunk, and levels of tumor markers CA125 and CA199 were 50.84 and 41.34 U/mL, respectively. At laparotomy for suspected malignancy, both adnexae formed "kissing ovaries", which were multinodulated with yellow serous fluid. Specimens from wedge resection submitted for frozen section showed a benign ovarian cyst. The final pathology report showed bilateral follicle cysts.

CONCLUSION

With the increasing use of gonadotropins in the management of infertility, ovarian enlargement secondary to hyperstimulation is common. Generally, symptoms appear between the 6th and 13th weeks of pregnancy and disappear thereafter. The hyperstimulated ovary often subsides after the first trimester. This case is unusual as the megalocystic ovary persisted after delivery. To the best of our knowledge, we report the first case of enlarged bilateral ovaries persisting 2 months after delivery.

Ganirelix acetate causes a rapid reduction in estradiol levels without adversely affecting oocyte maturation in women pretreated with leuprolide acetate who are at risk of ovarian hyperstimulation syndrome*

BACKGROUND

Elevated estradiol (E(2)) levels predispose to development of ovarian hyperstimulation syndrome (OHSS). Since GnRH antagonist is associated with a reduction in E(2) levels, we hypothesized that GnRH-antagonist treatment of women down-regulated with GnRH agonist who are at risk of OHSS might reduce E(2) levels and avoid cycle cancellation.

METHODS

Retrospective study in a university-based assisted reproduction technology (ART) programme in 87 patients treated with long luteal (LL) or microdose flare (MDF) with ovarian hyperresponse and 87 control patients without ovarian hyperresponse. GnRH-antagonist (ganirelix acetate) treatment was started and leuprolide acetate discontinued in women who failed to respond to a reduction in gonadotrophin dosage.

RESULTS

In the treatment group, there was a significant, reproducible reduction in serum E(2) levels. Mean E(2) at the start of ganirelix treatment was 4219.8 pg/ml and decreased in 24 h to 2613.7 pg/ml (36.7%; P < 0.001). An average of 24.9 +/- 8.8 oocytes were obtained at retrieval and an average of 19.1 +/- 8.0 were metaphase II (79.2%). Fertilization occurred in 13.9 +/- 8.1 embryos (72.8%). In this high risk group, two cases of severe OHSS (2.3%) occurred. The ongoing pregnancy rate was 51.8%. Compared with the control group, there were no statistically significant differences in the rate of oocyte recovery, oocyte maturity, 2PN rate, fertilization, cancellation, OHSS or pregnancy.

CONCLUSIONS

GnRH-antagonist treatment of women pretreated with GnRH agonist rapidly reduced circulating serum E(2) without adversely affecting oocyte maturation, fertilization rates or embryo quality and resulted in a high pregnancy rate in this subgroup of patients at risk of OHSS.

Incidence and prediction of ovarian hyperstimulation syndrome in women undergoing gonadotropin-releasing hormone antagonist in vitro fertilization cycles

OBJECTIVE

To determine the incidence of ovarian hyperstimulation syndrome (OHSS) in a large series of GnRH antagonist-stimulated cycles and to assess the predictive value of E2 and the number of follicles on the day of hCG administration.

DESIGN

Prospective cohort study of women undergoing IVF treatment with a GnRH antagonist protocol over a 2-year period.

SETTING

Tertiary university hospital.

PATIENT(S)

One thousand eight hundred one patients who underwent 2,524 cycles.

INTERVENTION(S)

Multifollicular ovarian stimulation with recombinant FSH and GnRH antagonist for IVF-ICSI treatment.

MAIN OUTCOME MEASURE(S)

Incidence of OHSS in GnRH antagonist cycles, predictive value of E2, and number of follicles on the day of hCG for OHSS occurrence.

RESULT(S)

Fifty-three patients were hospitalized because of OHSS (2.1%; 95% confidence interval [CI]:1.6-2.8). Early OHSS presented in 31 patients (1.2%; 95% CI: 0.9-1.8), whereas the late type was a complication in 22 patients (0.9%; 95% CI: 0.5-1.3). Late OHSS cases compared with the early OHSS cases always occurred in a pregnancy cycle (100% vs. 40%); had higher probability of being severe (72.7% vs. 42%), and more often were related to a multiple pregnancy (40% vs. 0). Receiver operating characteristic curve analysis for several E2 concentrations and number of follicles with a diameter of > or =11 mm revealed that the predictive value of the optimal threshold of > or =13 follicles (85.5% sensitivity; 69% specificity) was statistically significantly superior to the optimal threshold of 2,560 ng/L for E2 concentrations (53% sensitivity, 77% specificity) in identifying patients at risk for OHSS. Considering that severe OHSS represents the most clinically significant pattern, the combination of a threshold of > or =18 follicles and/or E2 of > or =5,000 ng/L yields a 83% sensitivity rate with a specificity as high as 84% for the severe OHSS cases.

CONCLUSION(S)

Clinically significant OHSS still remains a limitation of multifollicular ovarian stimulation for IVF even with the use of GnRH antagonist protocols. The number of follicles can discriminate the patients who are at risk for developing OHSS, whereas E2 concentrations are less reliable for the purpose of prediction. There is more than ever an urgent need for alternative final oocyte maturation-triggering medication.

Severe ovarian hyperstimulation syndrome in a 42-year-old woman with successful pregnancy after intracytoplasmic sperm injection embryo transfer

Ovarian hyperstimulation syndrome (OHSS) is an iatrogenic complication of ovulation induction for infertile women. It has been shown that patients suffering from OHSS are generally young because OHSS depends on the patient's ovarian reserve. Therefore, women ≥40 years of age seldom suffer from the severe form of OHSS. In the present study, we report a case of severe OHSS that occurred in a 42-year-old woman with a successful pregnancy after intracytoplasmic sperm injection (ICSI)-embryo transfer. She had been diagnosed as having polycystic ovary syndrome (PCOS). After 5 cycles of unsuccessful treatment with gonadotropins plus intrauterine insemination for her husband's asthenozoospermia, the treatment with assisted reproductive technology (ART) was indicated. In the third ART attempt, the patient was treated by ICSI-embryo transfer (ET) and she developed severe OHSS at 4 weeks' gestation. On admission, marked hemoconcentration, oligouria and hypo-albuminemia were diagnosed. A continuous autotransfusion system of ascites, which was developed to expand circulating plasma volume without exogenous albumin, was carried out for 5 h at a rate of 100-200 mL/h once a day for a total of 5 days. The course of the pregnancy was uneventful. At 37 weeks' gestation, a healthy baby boy weighing 3336 g was born by cesarean section when the patient was 43 years of age. The postoperative course was also uneventful. To the best of our knowledge, the present report describes the oldest woman showing severe OHSS. (Reprod Med Biol 2005; 4: 265-269).

Comparison of GnRH agonists and antagonists in assisted reproduction cycles of patients at high risk of ovarian hyperstimulation syndrome

BACKGROUND

During IVF or ICSI cycles, ovarian hyperstimulation syndrome (OHSS) is a major problem. The aim of this prospective, multicentre, comparative study (using historical controls) was to assess the efficacy of a GnRH antagonist protocol in preventing OHSS in selected patients who had experienced OHSS or had been at risk of OHSS in their previous IVF/ICSI attempt.

METHODS AND RESULTS

Patients underwent a new cycle where the same gonadotrophin protocol was used [same dose of recombinant FSH (rFSH)] but a different protocol was used for pituitary desensitization: cetrorelix 0.25 mg multiple-dose antagonist instead of GnRH agonist long protocol. Cetrorelix 0.25 mg was administered daily, starting when the leading follicle reached a diameter of 14 mm. In other words, rFSH was administered in the new cycle according to the dosage and the step-up or step-down modalities used during the previous cycle, independently of ultrasound findings and serum estradiol (E(2)) levels. Eighty-seven patients entered the study. Out of the 87 cycles involving GnRH agonists, 49 (56.3%) were cancelled and out of the 87 involving GnRH antagonists 28 (32.2%) were cancelled [McNemar's test; 95% confidence interval (CI) -35.8% to -11.2%; P < 0.001]. After GnRH agonist cycles, we recorded 24 cases of OHSS (18 moderate and six severe; 27.6%), whereas after the GnRH antagonist cycles there were 10 cases of OHSS (nine moderate and one severe; 11.5%) (95% CI-26.4% to -5.7%; P = 0.006). There was a statistically significant reduction in the total number of follicles with a diameter >10 mm (Wilcoxon's test; Z = 6.1; P < 0.001) and of E(2) levels on the day of HCG administration (2538 versus 4322.4 pg/ml; P < 0.001) in the GnRH antagonist cycles versus GnRH agonist cycles. Twenty-nine patients had an embryo transfer in the first cycle (76.3% of oocyte retrievals) and 57 in the cycle using GnRH antagonist (96.6%). This 20.3% difference was also significant (Z-test; 95% CI 6.8-36.0%; P = 0.003). After the antagonist cycles, 18 pregnancies (20.7 per initiated cycle; 31.6% per embryo transfer) were obtained.

CONCLUSIONS

Although this study presents some limitations owing to the use of historical controls, our data show a favourable effect of GnRH antagonists in reducing the incidence of OHSS and the number of assisted fertilization cycles cancelled because of the risk of OHSS in high responder patients. As a consequence, GnRH antagonist plus gonadotrophin administration could also increase the percentage of oocyte retrievals and embryo transfers in this high risk group of patients.

Serum estradiol positively predicts outcomes in patients undergoing in vitro fertilization

In patients undergoing in vitro fertilization, the presence of higher E(2) levels at the time of hCG administration predict a greater likelihood of ongoing pregnancy.

Induction of follicular growth and ovulation with urinary and recombinant gonadotrophins

Gonadotrophins have been used since the 1930s. By the 1990s, a pure biological extract of FSH was obtained. The increase in the demand for new assisted reproduction techniques led to the creation of recombinant FSH, 99% pure and highly consistent between batches, with no LH activity, and a high specific activity. In gonadotrophin protocols, follicular growth can be monitored with regular ultrasounds and/or hormonal testing, mainly oestradiol in the follicular phase. In assisted reproduction the adoption of ovulation induction strategies with GnRH analogues, control the endogenous secretion of LH, avoiding cancellations due to an early LH surge, and premature ovulation. Depending on the moment when pituitary suppression starts, there are short, ultra-short and long protocols The use of long protocols not only increases pregnancies and live births, it also allows an easier programming and simplifies IVF treatments. Ovarian stimulation entails some risks such as ovarian hyperstimulation syndrome and multiple pregnancies that can be avoided in many cases with an accurate prediction and an active prevention.

Ovarian hyperstimulation syndrome and assisted reproductive technologies: why some and not others?

BACKGROUND

alpha(2)-Macroglobulin (alpha(2)M) is a multifactorial binding protein, found in follicular fluid, that is a naturally occurring inhibitor of vascular endothelial growth factor (VEGF). The aim of this study was to determine if there is a relationship between serum VEGF levels, alpha(2)M levels and the development of OHSS in hyperstimulated subjects undergoing IVF (those with 15 or more oocytes).

METHODS

Venous blood was collected at the time of oocyte retrieval from subjects who yielded 15 or more oocytes. Serum samples were analysed for VEGF and alpha(2)M concentrations.

RESULTS

There was no statistically significant difference in serum VEGF levels at the time of oocyte retrieval between hyperstimulated subjects who did and did not subsequently develop OHSS [3.95 (3.3-4.4) versus 3.85 (3.3-4.5); P = 0.79]. By contrast, the serum level of alpha(2)M was statistically significantly higher in the group of subjects who did not develop OHSS [2.27 (1.91-2.58) versus 1.67 (1.45-1.73)].

CONCLUSIONS

These results suggest that elevated alpha(2)M levels are associated with a decreased risk of developing OHSS. alpha(2)M may act by 'removing and inactivating' VEGF, with higher levels providing increased protection against the syndrome. alpha(2)M measurements may help to differentiate those for whom it is safe to proceed with embryo transfer from those for whom it is not, because of the risk of OHSS.

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.

A novel approach for patients at risk for ovarian hyperstimulation syndrome: elective transfer of a single zona-free blastocyst on day 5

In this preliminary prospective randomized study of 420 patients undergoing ovarian stimulation for IVF/intracytoplasmic sperm injection (ICSI), 17 patients (4%) developed moderate to severe ovarian hyperstimulation syndrome (OHSS). Re-evaluation for OHSS on day 4 and 6 after oocyte retrieval identified one patient with continuous risk for severe OHSS, resulting in cancellation of the transfer (1/17, 5.8%). Prospectively, two of three patients had the zona pellucida of the blastocyst removed by pronase exposure prior to transfer. Significantly more patients became pregnant when a zona-free blastocyst was transferred in comparison to transfer of a single zona-intact embryo (9/11 or 82% versus 1/5 or 20%; P < 0.01). Higher ongoing singleton pregnancy rates were obtained when the zona pellucida was removed prior to the transfer (6/11 and 1/5 respectively). This preliminary prospective randomized study indicates that by prolonging the evaluation time for patients at risk of developing OHSS for up to 6 days after the oocyte retrieval, those patients at risk for developing severe OHSS can be identified. Transferring a single zona-free day 5 embryo (blastocyst) and freezing of the supernumerary embryos offers the patient with moderate OHSS an optimal chance for a singleton pregnancy, while avoiding the serious maternal complications of ovarian hyperstimulation syndrome.

OVARIAN HYPERSTIMULATION SYNDROME DURING INDUCTION OF OVULATION FOR INTRA UTERINE INSEMINATION

Ovarian Hyperstimulation Syndrome (OHSS) is a known iatrogenic complication of ovulation induction. Our experience of such complication while managing basic assisted conception cycles has been analysed in the present study. 12 such cases were identified in 976 cycles studied giving an overall incidence of 1.22%. All the cases were of mild to moderate variety and were managed conservatively. The duration of the complication ranged between 10 days to 6 weeks. Polycystic ovarian disease, LH: FSH ratio of more than 1, presence of four or more secondary follicles were found to be important predictive criteria. Identification of predictive factors of OHSS can be helpful in taking due care while using ovulation inducing drugs. Conception does worsen OHSS, but termination is usually not necessary.

The ovarian hyperstimulation syndrome

OBJECTIVE

To review the up-to-date literature concerning the pathogenesis of, risk factors for, prevention of, and therapy for the ovarian hyperstimulation syndrome, and to provide suggestions for management of this syndrome.

DESIGN

Literature review combined with on-site clinical experiences at the authors' institution of practice.

PATIENT(S)

Women who have risk factors for or manifest the ovarian hyperstimulation syndrome.

INTERVENTION(S)

Intravenous fluid management, thrombosis prevention techniques, paracentesis techniques, and critical care management protocols.

MAIN OUTCOME MEASURE(S)

Staging system of the ovarian hyperstimulation syndrome, criteria for outpatient versus hospitalization management, and indications for varying levels of interventional management.

RESULT(S)

The ovarian hyperstimulation syndrome, unique to the field of assisted reproductive technology, remains a largely elusive and unpredictable iatrogenic physiologic complication in the course of pharmacologic ovarian stimulation. Reliable information on risk factors, possible physiologic mechanisms, prevention techniques, and management is fortunately progressing, and overall advances are being made in this field. The present review is an attempt to summarize the modern literature regarding this syndrome and to use this current knowledge to provide a basis for acceptable management regimens.

CONCLUSION(S)

Ovarian hyperstimulation syndrome is a serious complication of assisted reproductive technology, with potential for critical morbidity and death. Physicians who prescribe medications known to be associated with this syndrome should be familiar with identifiable risk factors, means of prevention, and a system for staging and treating the disease and have a current knowledge base for putative models of pathogenesis.

Intrauterine donor insemination in single women and lesbian couples: a comparative study of pregnancy rates

The outcome of intrauterine donor insemination (IUI-DI) with frozen spermatozoa was analysed retrospectively in 675 cycles in single women (n = 122; 536 cycles) and lesbian (n = 35; 139 cycles) couples. The lesbian patients were younger at the initiation of treatment (mean 34.5 years; range 26-44) than the single women (mean 38.5; range 29-47) (P = 0.005). Clinical pregnancy rate was 36% in single women and 57% in lesbians (P < 0.05), the cumulative pregnancy rate after six cycles being 47% and 70% respectively, although the outcome was similar when related to age. The miscarriage rate was higher (35%) in single women than in lesbians (15%; P < 0.05), the rate being independent of maternal age. There were no apparent differences seen between the two groups with respect to the possible effect of parity, duration of infertility, causes of infertility and type of treatment at initiation of treatment; the sole exception was that the age of lesbian women was statistically significantly younger than that of single women (P < 0.005). When corrected for age, the pregnancy rates and complications were lower and higher respectively in single women but these differences did not reach statistical significance. However, the disparity between the treatment outcomes of single women and lesbian patients of similar ages may also reflect the fact that single women are likely to have failed to conceive for a period of time prior to referral to a specialist centre for treatment.

Ovarian hyperstimulation syndrome

Ovarian hyperstimulation syndrome is an iatrogenic complication of assisted reproduction. In its most severe form, it is potentially fatal. The major clinical components are marked ovarian enlargement and increased capillary permeability leading to ascites, hydrothorax and pericardial effusion. Severe cases are associated with thromboembolic phenomena, respiratory distress and renal failure. The definitive pathophysiology is unknown. The available evidence would support a central role for inflammatory cytokines and angiogenic growth factors. Ultrasound examination and serum oestradiol values are currently used to predict patients at risk. The ideal treatment is prevention, but there has been only limited success. The main aims of treatment are to correct fluid imbalance, maintain renal perfusion and support the patient until the condition resolves. Drug therapy has a limited role, although anticytokine agents may prove useful.

Prospective study of the clinical and laboratory parameters of patients in whom ovarian hyperstimulation syndrome developed during controlled ovarian hyperstimulation for in vitro fertilization

OBJECTIVE

To compare patient characteristics and clinical and laboratory parameters in patients in whom ovarian hyperstimulation syndrome (OHSS) develops with those in whom it does not develop.

DESIGN

Prospective cohort study.

SETTING

Reproductive medicine unit at a university medical center.

PATIENT(S)

All patients undergoing IVF (n = 428) who received controlled ovarian hyperstimulation during a 6-month period.

INTERVENTION(S)

Prospective data collection.

MAIN OUTCOME MEASURE(S)

Patient characteristics (age, body mass index, medical history, smoking habits) and clinical and laboratory data obtained during controlled ovarian hyperstimulation were evaluated in patients who had severe OHSS, any degree of OHSS, or a significant risk of OHSS and compared with the remaining populations.

RESULT(S)

Severe OHSS developed in 18 patients (4.2%) and mild or moderate OHSS developed in 7.3%. As a group, all the patients with OHSS were significantly younger, received lower doses of gonadotropins, had ovaries containing a higher number of total and large follicles, had a higher number of retrieved oocytes, and had a higher pregnancy rate than the patients without OHSS. The patients with severe OHSS also had an increased prevalence of allergy (56% versus 21%) and were more likely to ultimately give birth.

CONCLUSION(S)

The observed differences may be useful in elucidating the pathophysiology of OHSS and identifying patients who are at increased risk for OHSS.

Obstetric outcome of in vitro fertilized pregnancies complicated by severe ovarian hyperstimulation syndrome: a multicenter study

OBJECTIVE

To assess the outcome of pregnancies conceived with the use of IVF that are complicated by severe ovarian hyperstimulation syndrome (OHSS).

DESIGN

A retrospective nationwide multicenter study.

SETTING

Sixteen of 19 tertiary care medical centers in Israel.

PATIENT(S)

All patients undergoing IVF who were hospitalized for severe OHSS between January 1987 and December 1996.

MAIN OUTCOME MEASURE(S)

Pregnancy rate (PR) and rates of multiple gestation, miscarriage, ectopic pregnancy, obstetric complications, and intervention.

RESULT(S)

A total of 163 patients who had severe OHSS after IVF treatment were identified, of whom 142 (87.1%) had undergone ET. The clinical PR was 73.2%; 42.3% were singletons, 33.6% were twins, 17.3% were triplets, and 6.7% were quadruplets. The miscarriage rate was 29.8%, whereas the incidence of ectopic pregnancy was 1.9%. Forty-four percent of all births were premature, and 62.1% of all newborns had low birth weight. The most common antenatal complications were pregnancy-induced hypertension (13.2%), gestational diabetes (5.9%), and placental abruption (4.4%). The rate of cesarean section was 44.1%.

CONCLUSION(S)

Among patients who have severe OHSS after IVF treatment, the pregnancy rate and the rates of multiple gestation, miscarriage, prematurity, low birth weight, pregnancy-induced hypertension, gestational diabetes, and placental abruption are significantly higher than those reported previously for pregnancies conceived with the use of assisted reproductive techniques.

Role of vascular endothelial cell growth factor in Ovarian Hyperstimulation Syndrome

Controlled ovarian hyperstimulation with gonadotropins is followed by Ovarian Hyperstimulation Syndrome (OHSS) in some women. An unidentified capillary permeability factor from the ovary has been implicated, and vascular endothelial cell growth/permeability factor (VEGF) is a candidate protein. Follicular fluids (FF) from 80 women who received hormonal induction for infertility were studied. FFs were grouped according to oocyte production, from group I (0-7 oocytes) through group IV (23-31 oocytes). Group IV was comprised of four women with the most severe symptoms of OHSS. Endothelial cell (EC) permeability induced by the individual FF was highly correlated to oocytes produced (r2 = 0.73, P < 0.001). Group IV FF stimulated a 63+/-4% greater permeability than FF from group I patients (P < 0. 01), reversed 98% by anti-VEGF antibody. Group IV fluids contained the VEGF165 isoform and significantly greater concentrations of VEGF as compared with group I (1,105+/-87 pg/ml vs. 353+/-28 pg/ml, P < 0. 05). Significant cytoskeletal rearrangement of F-actin into stress fibers and a destruction of ZO-1 tight junction protein alignment was caused by group IV FF, mediated in part by nitric oxide. These mechanisms, which lead to increased EC permeability, were reversed by the VEGF antibody. Our results indicate that VEGF is the FF factor responsible for increased vascular permeability, thereby contributing to the pathogenesis of OHSS.

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.

The pathogenesis of ovarian hyperstimulation syndrome: a continuing enigma

PURPOSE

Our purpose was to review the available literature concerning the pathogenesis of ovarian hyperstimulation syndrome and, in light of the most recent information, to attempt to provide further insight on this iatrogenic complication associated with the induction of ovulation.

METHODS

Published studies related to this topic were identified through a computerized bibliographic search.

CONCLUSIONS

The exact mechanism for the development of ovarian hyperstimulation syndrome is still obscure. It is well established that the syndrome is associated with the process of ovulation induced by either luteinizing hormone or human chorionic gonadotropin. Following ovulation, one or more substances produced by the ovary are liberated in excess, increasing capillary permeability, resulting in the clinical features of the syndrome. It may well be that the syndrome is not triggered by a single mechanism but by the production and secretion of several substances acting in concert. These may include prostaglandins, cytokines, the ovarian reninangiotensin system, vascular endothelial growth factor, and nitric oxide.

Urinary follicle-stimulating hormone for normogonadotropic clomiphene-resistant anovulatory infertility: prospective, randomized comparison between low dose step-up and step-down dose regimens

A low dose step-up and step-down regimen for induction of ovulation using urinary FSH was compared in a prospective randomized fashion in 37 normogonadotropic clomiphene-resistant oligo- or amenorrheic infertile women. The objectives was to assess potential differences in duration of treatment, ovarian stimulation (serum FSH levels), and response [serum estradiol (E2) levels and number and size of follicles]. Monitoring (blood sampling and transvaginal sonography) took place on the day of initiation of treatment, the first day of ovarian response as assessed by ultrasound (i.e. the first day a follicle > or = 10 mm could be recognized), the day of hCG administration to induce ovulation, and 3 days thereafter. The median duration of treatment in the low dose step-up group was 18 (range, 7-41) days compared to 9 (range, 4-16) days in the step-down group (P = 0.003), and the total numbers of ampules administered were 20 (range, 7-69) and 14 (range, 7-33), respectively (P = NS). Serum FSH levels from the first day of sonographic ovarian response until the administration of hCG were constant (median increase, 2%/day) in patients receiving the low dose step-up protocol, but showed a decrease (median, 5%/day) in step-down cycles (P < 0.001). Monofollicular growth, defined as not more than one follicle 16 mm or larger on the day of hCG administration, was observed in 56% of low dose step-up and 88% of step-down cycles (P = 0.04). The percentage of patients with normal range periovulatory E2 serum levels (500-1500 pmol/L) was 33% in the low dose step-up group vs. 71% in the step-down group (P = 0.03). We conclude that a step-down protocol for gonadotropin induction of ovulation exhibits a more physiological, late follicular phase FSH serum profile than a low dose step-up protocol. This results in a shorter duration of treatment, a greater number of monofollicular cycles, and more cycles with periovulatory E2 levels within the normal range in the step-down protocol.

Low intraovarian vascular resistance: a marker for severe ovarian hyperstimulation syndrome

OBJECTIVE

To assess intraovarian blood flow in relation to the severity of ovarian hyperstimulation syndrome (OHSS) after controlled ovarian hyperstimulation.

DESIGN

A prospective study.

SETTING

Monash IVF, Clayton, Victoria, Australia.

PATIENT(S)

Thirty patients with OHSS after embryo or gamete transfer who also had sonographic evidence of ascites.

MAIN OUTCOME MEASURE(S)

The resistance to blood flow within the ovaries of 11 patients with severe OHSS and 19 patients with mild OHSS was measured by using transabdominal ultrasonography with color flow and pulsed Doppler imaging.

RESULT(S)

The pulsatility index (PI), resistance index (RI), and the S-D ratio, all measures of downstream vascular impedance, were significantly lower in those patients with severe OHSS. In cases with RI < 0.48, more than two thirds of the patients had a pleural effusion, whereas patients with either PI < 0.75 or S-D < 1.92 had pleural effusion in over one half of the cases. It was notable that blood flow velocity did not differ significantly between the two groups despite the changes in vascular impedance.

CONCLUSION(S)

There appears to be a close correlation between the severity of OHSS and the resistance to blood flow within the stimulated ovaries. Measurement of intraovarian vascular resistance before gamete transfer or ET in patients undergoing controlled ovarian hyperstimulation may help in predicting those patients at particular risk of developing severe OHSS.

Profound hypotension and sodium retention with the ovarian hyperstimulation syndrome

A 34-year-old woman developed profound hypotension and sodium retention following hormonal induction of ovulation. There was a transient response to infusion of albumin, but hypotension and hyponatremia persisted for 5 days. Nevertheless, acute renal failure did not develop. Available information indicates that this syndrome can occur with exogenous administration of gonadotrophic hormones or with a successful pregnancy.

Fibrinolytic parameters in women undergoing ovulation induction

OBJECTIVE

The purpose of this study was to evaluate the effect of elevated levels of circulating estradiol on the clotting and fibrinolytic system in patients undergoing controlled ovarian hyperstimulation.

STUDY DESIGN

Fifty-two patients undergoing controlled ovarian hyperstimulation with human menopausal gonadotropins or urofollotropin were asked to participate. Blood for hemostasis parameters was obtained on the days that patients returned for estradiol sampling. Sample days were identified as cycle days 1 to 5 (baseline), 6 to 9, and 10 to 14. Each factor was analyzed by repeated-measures analysis of variance and correlation analysis.

RESULTS

A significant decline was observed for tissue plasminogen activator antigen and plasminogen activator inhibitor type 1 activity from baseline to cycle days 10 to 14. As serum estradiol levels increased throughout each phase (maximum mean estradiol 739.8 pg/ml), a significant linear decrease was observed for both tissue plasminogen activator antigen and plasminogen activator inhibitor type 1 activity, whereas thrombin-antithrombin III complexes did not change significantly. A significant positive correlation was also observed for plasminogen activator inhibitor activity and tissue plasminogen activator antigen level over all cycle days examined.

CONCLUSION

Down-regulation of the fibrinolytic system was observed as estradiol levels increased. However, thrombin formation did not change, thus suggesting that elevated circulating estradiol alone does not predispose to a thromboembolic event.