Five-day anastrozole in infertility needs supplemental hCG

19 05 2011

To the Editor:

I read with great interest the article by Tredway D et al. (1), in which they concluded that “in terms of ovulation rates, 5-day anastrozole at 1,5, and 10 mg/d was less effective than CC at 50mg/d for cycle 1”. They have done a good work.

However, surprisingly, the ovulation rates for anastrozole groups were obviously low. In their Results Section, they mentioned that “most patients receiving anastrozole 1 mg/d (72.7%) and 5 mg/d (73.5%) achieved monofollicular development (one follicle ≥ 17 mm in diameter), compared with 70.4% of patients receiving CC”. We argue that monofollicular development (one follicle ≥ 17 mm in diameter) rates were similar between anastrozole and CC, why was ovulation rates difference so significant (the ovulation rates for anastrozole at 1, 5, and 10 mg/d were 30.4%, 36.8% and 35.9%, respectively, compared with 64.9% for CC at 50 mg/d)?

We believe that it is due to lack of supplemental hCG. Read the rest of this entry »