OBJECTIVE: To probe into the effects of letrozole combined with dexamethasone on anti-mullerian hormone（ AMH）

nitric oxide（ NO） and vascular endothelial growth factor（ VEGF） in patients with polycystic ovarian syndrome. METHODS: Totally 155 patients with polycystic ovarian syndrome admitted into Meishan Women and Children’s Hospital from Oct. 2018 to Nov. 2019 were extracted. The included patients were sorted from 1 to 155

and the odd number of patients were included in the control group and the even number of patients were included in the combined group. Seventy-eight patients in the control group were treated with letrozole alone

while 77 patients in the combined group were treated with letrozole combined with dexamethasone. The peripheral blood was collected before treatment and at the end of treatment

and changes of hormone-related indicators and serum-related indicators were detected and compared after treatment. The ovulation of two groups was detected and compared at the end of treatment.The incidence of adverse drug reactions in two groups was recorded. RESULTS: At the end of treatment

the levels of luteinizing hormone

testosterone

AMH and VEGF in two groups were lower than those before treatment

and the level of NO was higher than that before treatment; the levels of luteinizing hormone

testosterone

AMH and VEGF in the combined group were lower than those in control group

and the level of NO in the combined group was higher than that in the control group

with statistically significant differences（ P<0. 05）. At the end of treatment

the number of mature follicle in the combined group was more than those in the control group

and the maximum follicle diameter in the combined group was longer than that in the control group

with statistically significant differences（ P < 0. 05）.Minor adverse drug reactions occurred during treatment in both groups

and the difference in the incidence of adverse drug reactions was not statistically significant（ P > 0. 05）. CONCLUSIONS: Compared with single use of letrozole

letrozole combined with dexamethasone in the treatment of polycystic ovarian syndrome can regulate the levels of hormones

decrease the serum levels of AMH and VEGF

increase the level of NO

and have better ovulation induction effects with few adverse drug reactions

which is safe and reliable.