Ok i think i found the answer to my own question in a clinical study results.... So the hcg dose is adjusted according to estrogen levels and ohhs risk. Patients with less than 25 follcles on day of trigger or with estrogen less than 5000 pg/ml recieve 10000 iu hcg. Patients with 25-35 follicles or Estrogen in the range of 5000 -10000 pg/ml recieve 5000iu hcg. Those with highest risk of ohss, determined by the presence of more than 35 follies and estrogen of more than 10000 pg/ml recieve only 3000 iu hcg.
Last cycle i only had around 8-9 follies and low estrogen and triggered with 10000 iu hcg, this time i have about 20 and high estrogen about 9200 iu. i was told to coast (i.e not take any gonal yesterday to keep estrogen at bay it was at 8150 yesterday) and it obviously did the trick as estrogen has only risen by a 1000 so i'm triggering, but with 5000 iiu hcg!
