Serum vascular endothelial growth factor levels before starting gonadotropin treatment in women who have developed moderate forms of ovarian hyperstimulation syndrome

Continuous vaginal and bilateral thoracic fluid drainage for management of severe ovarian hyperstimulation syndrome

Severe ovarian hyperstimulation syndrome (OHSS) is a serious and potentially fatal complication of ovarian stimulation. A 29-year-old nulligravid patient with anovulatory infertility was treated with in vitro fertilization. Six days after embryo transfer, the patient presented with complaint of abdominal bloating, nausea, vomiting and shortness of breath. Severe late-onset OHSS, with massive ascites and pleural effusion, was diagnosed. Posterior colpotomy was performed under general anesthesia, a Foley catheter was inserted into the posterior cul-de-sac, and bilateral chest drainage tubes were left for continuous drainage. In total, 13.2 liters of ascites and 6.1 liters of pleural fluid were drained in 8 days. Continuous drainage of ascites and pleural effusion improved the patient's comfort without need for repeated transvaginal and thoracic aspirations.

Low-dose HCG is useful in preventing OHSS in high-risk women without adversely affecting the outcome of IVF cycles

Severe ovarian hyperstimulation syndrome (OHSS) is a rare but potentially fatal condition associated with conventional IVF treatment. It is found predominantly in women with polycystic ovaries who have an exaggerated response to exogenous FSH, leading to a large number of follicles and an overproduction of vascular endothelial growth factor with resultant excessive increases in vascular permeability. There is evidence to suggest that OHSS is also linked to the use of human chorionic gonadotrophin (HCG) to induce ovulation. Therefore, while HCG is essential for corpus luteum function, high amounts of HCG can lead to OHSS in high responders. In a pilot study, infertile patients at high risk of developing OHSS were given half the current minimum dose of HCG (i.e. 2500 IU). No woman developed moderate or severe OHSS; 13 women (61.9%) conceived and there were three twin pregnancies. In women at high risk of OHSS, a low dose of HCG appears to prevent the development of OHSS without compromising success rates.

Vascular endothelial growth factor production by circulating immune cells is elevated in ovarian hyperstimulation syndrome

BACKGROUND

Ovarian hyperstimulation syndrome (OHSS) is an iatrogenic disease manifesting itself by ovarian enlargement and massive ascites with increased peritoneal capillary permeability. Although vascular endothelial growth factor (VEGF) is considered to play the main role in developing OHSS, its precise mechanism remains unclear. In this study, we examined possible roles of circulating immune cells in the pathogenesis of OHSS.

METHODS

Peripheral blood mononuclear cells (PBMC) and plasma were collected from healthy non-pregnant volunteers and from patients receiving ovulation induction for IVF. PBMC were cultured for 48 h. Plasma and/or medium concentrations of VEGF, estradiol and progesterone were measured using enzyme-linked immunosorbent assay and radioimmunoassay kits.

RESULTS

VEGF production by cultured PBMC and plasma concentrations of VEGF taken from patients with early onset OHSS (n = 12) were significantly higher than those in non-pregnant volunteers and patients without OHSS whose oocyte retrieval rates were similar to that of OHSS patients. OHSS patients were further classified into a high plasma VEGF concentration group and a high culture medium VEGF group. There was no significant correlation among VEGF production by PBMC and plasma concentration of VEGF, estradiol or progesterone.

CONCLUSION

Although mechanistic evidence has not been provided, our study does provide new evidence to suggest that circulating immune cells are involved in the pathogenesis of OHSS via VEGF production.

Vascular endothelial growth factor levels in serum and plasma from patients undergoing controlled ovarian hyperstimulation for IVF

BACKGROUND

Vascular endothelial growth factor (VEGF) has been investigated as a marker of ovarian response to controlled ovarian hyperstimulation and as a predictor of ovarian hyperstimulation syndrome (OHSS) in IVF cycles. In most studies, serum has been used for circulating VEGF concentration measurement, but it has been suggested that plasma is the preferred medium to measure VEGF levels because of the potential contribution of VEGF released from platelets during blood clotting. This study investigated VEGF concentrations in paired serum and plasma samples from patients undergoing controlled ovarian hyperstimulation for IVF.

METHODS

Serum and plasma VEGF levels, as well as the number of platelets, were measured in 30 IVF patients who comprised three study groups delineated according to the estradiol (E(2)) serum concentration reached on the day of HCG administration: 10 patients having low E(2) serum levels (<1500 pg/ml, group L), 10 patients having intermediate E(2) serum levels (1500-3000 pg/ml, group I) and 10 patients having high E(2) serum levels (>3000 pg/ml, group H).

RESULTS

There was a statistically significant correlation between plasma and serum VEGF levels (rho = 0.61; P < 0.005) for the entire population studied, although serum values were higher by a factor of approximately 6-fold. No significant correlation was found between peripheral blood VEGF concentrations and serum E(2) or follicle number on HCG day or the number of oocytes collected. Similarly, paired serum and plasma VEGF measurements did not correlate with platelet count.

CONCLUSIONS

Serum and plasma VEGF concentrations are strongly correlated in paired samples from infertile patients undergoing controlled ovarian hyperstimulation. However, neither serum nor plasma VEGF levels were correlated with parameters associated with ovarian follicular activity. Peripheral blood VEGF levels were not correlated with platelet count.

The science behind 25 years of ovarian stimulation for in vitro fertilization

To allow selection of embryos for transfer after in vitro fertilization, ovarian stimulation is usually carried out with exogenous gonadotropins. To compensate for changes induced by stimulation, GnRH analog cotreatment, oral contraceptive pretreatment, late follicular phase human chorionic gonadotropin, and luteal phase progesterone supplementation are usually added. These approaches render ovarian stimulation complex and costly. The stimulation of multiple follicular development disrupts the physiology of follicular development, with consequences for the oocyte, embryo, and endometrium. In recent years, recombinant gonadotropin preparations have become available, and novel stimulation protocols with less detrimental effects have been developed. In this article, the scientific background to current approaches to ovarian stimulation for in vitro fertilization is reviewed. After a brief discussion of the relevant aspect of ovarian physiology, the development, application, and consequences of ovarian stimulation strategies are reviewed in detail.

Expression of the vascular endothelial growth factor and its receptors and effects of VEGF during in vitro maturation of bovine cumulus-oocyte complexes (COC)

A complete VEGF system consisting of the ligand and two of its receptors has been detected for the first time in the bovine cumulus-oocyte-complex (COC). In the course of a 24 hr in vitro maturation procedure (IVM), expression of the smaller VEGF transcripts and their specific receptors flt and flk changed remarkably in a time-dependent manner as observed by RT-PCR. The transcript concentrations of VEGF declined within 24 hr of culture, whereas both receptor mRNAs were found enriched between 6 and 12 hr of IVM. In the follicular fluid of growing ovarian follicles, immunoreactive VEGF, measured by RIA, increased significantly, reaching highest concentrations immediately before ovulation of the oocyte. The immunohistochemical localization of VEGF in bovine COCs revealed strong signals within the cumulus cell complex clearly extending beyond the oocyte cytoplasm at the beginning of in vitro maturation. After 24 hr, IVM immunoreactive VEGF disappeared remarkably from cumulus cells and the oocyte cytoplasm. An exogenous application of VEGF at the beginning of a 24 hr IVM significantly improved cleavage rates of zygotes and their development into bovine embryos showing obvious synergistic effects in combination with FSH, when compared with untreated control embryos. In addition, the number of blastomeres in deriving blastocysts increased after VEGF supplementation. These results indicate a functional VEGF system controlling important events beside the known angiogenetic effect during in vivo and in vitro maturation of the bovine COC, possibly affecting the early embryonic viability.

VEGF: an update on biological and therapeutic aspects

Vascular endothelial growth factor (VEGF) is an endothelial cell-specific mitogen and an angiogenic inducer as well as a mediator of vascular permeability. VEGF is essential for developmental angiogenesis and is also required for female reproductive functions and endochondral bone formation. Substantial evidence also implicates VEGF in tumors and intraocular neovascular syndromes. Currently, several clinical trials are ongoing to test the hypothesis that the inhibition of VEGF activity may be beneficial for these conditions.

Role of vascular endothelial growth factor in ovarian physiology and pathology

OBJECTIVE

To review the current literature on the role of vascular endothelial growth factor/vascular permeability factor (VEGF/VPF) in ovarian physiology and pathology.

DESIGN

A computerized search was conducted to identify relevant in vitro and in vivo studies published in English. MEDLINE, Current Contents, and the Index Medicus were searched for studies published before January 2000.

RESULT(S)

VEGF/VPF is an angiogenic factor and a potent mitogen for vascular endothelium. During reproductive life, VEGF/VPF plays a role in the cyclic growth of ovarian follicles and corpus luteum development and maintenance, mediating ovarian angiogenesis. VEGF/VPF expression and secretion are induced by both FSH and LH/hCG receptor-activated pathways.

CONCLUSION(S)

VEGF/VPF expression and production within the ovary are critical for normal reproductive function. Defects in angiogenesis may contribute to a variety of disorders including anovulation and infertility, pregnancy loss, ovarian hyperstimulation syndrome, and ovarian neoplasms.