Research question:

What is the influence of ethnicity on the outcome of ovulation induction with clomifene citrate in women with polycystic ovary syndrome (PCOS)?

Design:

This was a retrospective cohort study. In total, 420 women diagnosed with PCOS who were of Northern European, Mediterranean, African, South-East Asian or South American descent, and who started ovulation induction treatment with clomifene citrate, were included. All women were treated with clomifene citrate according to a standardized treatment regimen. The minimal effective dose of clomifene citrate and prevalence of clomifene resistance (CRA) were assessed, and the chance of becoming ovulatory was predicted.

Results:

Differences were observed in body mass index (P = 0.008), waist circumference (P = 0.036) and serum LH, insulin and androgen concentrations (all P < 0.001) in women of different ethnicities with PCOS. Compared with women of Northern European descent, the minimal effective dose of clomifene citrate in women of other ethnic groups was not significantly different. The prevalence of CRA (P = 0.574) was similar in all ethnic groups A similar chance of ovulation (P = 0.504) was predicted for the different ethnic groups.

Conclusions:

This is the first study aiming to link ethnicity to ovulation induction outcome in PCOS. Although women of different ethnicities who have PCOS exhibit a variation in phenotypic expression, there do not appear to be differences in the prevalence of clomifene-resistant anovulation or the minimal effective dose of clomifene citrate. Furthermore, a prediction model revealed no significant differences in the predicted chance of ovulation. A larger cohort is needed to validate these findings.