Preventive Application of Letrozole Decrease Incidence of Early Onset of OHSS

The Randomized Controlled Trial Study of Letrozole in the Prevention of Medium and Severe Ovarian Hyperstimulation Syndrome in Invitro Fertilization Treatment

Letrozole is one kind of aromatase inhibitors which may have effect on decrease estrogen in luteal phase and inhibit the luteal function of ovary. In 2009, Letrozole was reported as one candidate for the treatment or prevention of ovarian hyperstimulation syndrome.

Letrozole was proved to be effective in decreasing the estradiol level of luteal phase after ovum picked up. In this randomized controlled study, investigators try to observe the effectiveness of letrozole on decreasing the incidence of early ovarian hyperstimulation syndrome and vascular epithelium growth factor level of women with high ovarian hyperstimulation syndrome risks.

Inclusion Criteria:

• infertile women undergoing IVF treatment with more than 25 oocytes collected.

Exclusion Criteria:

• letrozole contraindications,e.g. severe hepatic and renal dysfunction