GNRH1 and ovarian hyperstimulation syndrome: All 40 patients with severe OHSS were diagnosed with significant ascites on the day of GnRH antagonist initiation (27.5% massive/tense ascites; 72.5% moderate/marked ascites), which progressively declined to moderate levels (35%) or low/no detectable levels (65%) at the end of the monitoring period (p < 0.01) (Figure3).