Objective: To observe the effect of low dose triptorelin in later luteal phase on
pituitary down
regulation for patients
undergoing IVF ET. Methods: One hundred and twenty
patients were randomly divided into 2 groups(A and B). In group A, the patients were treated with triptorelin of 0.1 mg subcutaneously daily started on day 21 of menstrual cycle for 7 days. In group B, the patients were treated with long protocol of Buserelin intranasal spray. Comparisons were made between the groups in serum concentrations of FSH, LH, E2, T, PRL and P on the third day (D3) of superovulation cycle and on the day of hCG administration, highly purified follicle stimunating hormone (HP) dosages, and so on. Results: In group A, mean serum LH level on D3 and the day of hCG was ( 1.55 ± 0.99 ) U/L and ( 2.70 ± 1.45 ) U/L, E2 was ( 85.66 ± 13.13 ) pmol/L and ( 5 451.31 ± 1 900.61 ) pmol/L, respectively, significantely lower than those of group B ( P < 0.001 ; P < 0.01 ; P < 0.05 ; P < 0.001 ). Mean HP(75 IU/ Amp) dosage per treatment cycle in group A was 28.20 ± 11.03 ampoules, significantly higher than 22.30 ± 6.40 ampoules in group B( P < 0.001 ). Conclusions: Low dose triptorelin in later luteal phase is effective for down
regulation of pituitary and produces more suppression on endogenous LH in pituitary than Buserelin long protocl.