LOW INTRAOVARIAN VASCULAR-RESISTANCE - A MARKER FOR SEVERE OVARIAN HYPERSTIMULATION SYNDROME

Objective: To assess intraovarian blood flow in relation to the severi ty of ovarian hyperstimulation syndrome (OHSS) after controlled ovaria n hyperstimulation. Design: A prospective study. Setting: Monash IVF, Clayton, Victoria, Australia. Patient(s): Thirty patients with OHSS af ter embryo or gamete transfer who also had sonographic evidence of asc ites. Main Outcome Measure(s): The resistance to blood flow within the ovaries of 11 patients with severe OHSS and 19 patients with mild OHS S was measured by using transabdominal ultrasonography with color flow and pulsed Doppler imaging. Result(s): The pulsatility index (PI), re sistance index (RI), and the S-D ratio, all measures of downstream vas cular impedance, were significantly lower in those patients with sever e 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 nota ble that blood flow velocity did not differ significantly between the two groups despite the changes in vascular impedance. Conclusion(s): T here appears to be a close correlation between the severity of OHSS an d the resistance to blood flow within the stimulated ovaries. Measurem ent of intraovarian vascular resistance before gamete transfer or ET i n patients undergoing controlled ovarian hyperstimulation may help in predicting those patients at particular risk of developing severe OHSS . (C) 1997 by American Society for Reproductive Medicine.