Altered osmotic thresholds for arginine vasopressin secretion and thirst during superovulation and in the ovarian hyperstimulation syndrome (OHSS): relevance to the pathophysiology of OHSS.

OBJECTIVE: To test the hypothesis that decreases in and maintenance of a new steady state in plasma osmolality and sodium level in ovarian hyperstimulation syndrome (OHSS) are due to altered osmoregulation of arginine vasopressin secretion and thirst. DESIGN: Prospective study. SETTING: IVF-ET program in a university-based assisted reproductive treatment center. PATIENT(S): Eight women undergoing superovulation for IVF-ET and five women with normal menstrual cycles. INTERVENTION(S): Two-hour infusion of 5% saline on day 3 or 4 after hCG administration in patients undergoing IVF or in the early luteal phase in controls. A 5% saline infusion test was done on day 10 after hCG administration in one patient with OHSS and one patient without OHSS, both of whom were undergoing IVF. MAIN OUTCOME MEASURE(S): Comparison of changes in thresholds for thirst and plasma vasopressin to plasma osmolality. Changes in urine osmolality, plasma electrolytes, hemoglobin level, and hematocrit were assessed at baseline and during infusion of 5% saline. RESULT(S): The sensitivity of the changes in arginine vasopressin secretion and thirst after 5% saline infusion was similar in IVF patients on day 3 or 4 after hCG and controls. However, the osmotic threshold was significantly lower by 6 mOsm/kg in IVF patients. By day 10 after hCG, the lower osmotic thresholds for arginine vasopressin secretion and thirst persisted in OHSS, although the sensitivity to arginine vasopressin secretion was markedly reduced. CONCLUSION(S): The osmotic thresholds for arginine vasopressin secretion and thirst are reset to lower plasma osmolality during superovulation for IVF-ET. This new lower body tonicity is maintained until at least day 10 after hCG in OHSS. Decreases in plasma osmolality and plasma sodium levels in OHSS are due to altered osmoregulation rather than electrolyte losses; correction of apparent "electrolyte imbalance" in OHSS is therefore inappropriate.

Coexistent hemoconcentration and hypoosmolality during superovulation and in severe ovarian hyperstimulation syndrome: a volume homeostasis paradox.

OBJECTIVE: To investigate the concomitant time courses of the changes in osmolality and calculated blood volume during the genesis of ovarian hyperstimulation syndrome (OHSS). DESIGN: Prospective longitudinal study. SETTING: IVF-ET program in a university-based assisted reproductive technology center. PATIENT(S): Thirty women undergoing superovulation for IVF-ET. INTERVENTION(S): Blood and urine samples were obtained on seven occasions from the start of FSH stimulation until a pregnancy test. Five women with severe OHSS had daily blood and urine tests during hospitalization. MAIN OUTCOME MEASURE(S): Changes in serum and urine osmolality, serum electrolytes, albumin, hemoglobin, and hematocrit. RESULT(S): Blood volume in women with OHSS decreased significantly by 20% from days hCG +2 to +4, followed by a sustained increase of 30% above baseline from days hCG +8 to +12. There was no statistically significant change in blood volume in women without OHSS. There was a sharp decrease in serum osmolality in women without OHSS between days 0 and hCG +2, which recovered toward baseline from day 4 after hCG. In women with OHSS, there was an unexpected increase in osmolality of 6 mOsm/kg between days hCG -2 and 0, followed by a decrease of 8 mOsm/kg by day hCG +2; this was sustained until day hCG +12. Patients with OHSS demonstrated a concentration and dilution of their urine during the acute and recovery phases of the syndrome, respectively, despite persistence of the hypoosmolar state. CONCLUSION(S): Decreased osmolality in severe OHSS is maintained despite significant decreases and increases in blood volume, suggestive of fundamental alterations in osmoregulation.

Severe haemophilia following use of donor eggs: implications for screening of prospective donors.

Oocyte donation has become a common treatment modality for a range of infertility conditions. The Shared Egg Donation (SED) scheme is one of various strategies that now exist to try and overcome shortages, that have invariably occurred from the very success of oocyte donation procedures. Despite a reassuring positive profile that has been demonstrated, some residual concerns still exist with regard to the SED programme. We report the first case of severe haemophilia following use of donor eggs in the SED scheme. The case has not only illustrated potential problems that can occur with egg donation schemes, but also suggested a plausible model on which to base future management of similar cases. The case furthermore illustrates that there is no substitute for 'good practice' in ensuring those risks and concerns of egg donation programmes are kept to acceptable limits.

Severe ovarian hyperstimulation syndrome following salvage of empty follicle syndrome.

We report a case of severe ovarian hyperstimulation syndrome (OHSS) following a rescue of empty follicle syndrome (EFS). This suggests that the risk of developing OHSS remains unaltered even in the presence of EFS. The case supports the possibility of obtaining oocytes that fertilize and cleave normally after a second dose of human chorionic gonadotrophin (HCG) and a repeat oocyte retrieval. It supports the suggestion that the follicles are not necessarily empty in EFS. It demonstrates further that OHSS cannot be prevented by aspiration of follicular fluid and patients with large numbers of follicles and EFS must be warned of this potential complication.