Key finding
In 750 women with PCOS who were trying to conceive, letrozole led to more live births than clomiphene: 27.5% against 19.1% over up to five treatment cycles. Ovulation was also more frequent with letrozole (61.7% against 48.3% of cycles). Twin rates and birth defect rates did not differ significantly between the groups.
Letrozole is now the first-line medicine for ovulation induction in PCOS/PMOS in the international guideline, although its use for this purpose is off-label in many countries, and pregnancy should be ruled out before each cycle. Refer women who are not ovulating to a fertility service early, and support weight, metabolic and nutritional health alongside treatment.
Legro RS, Brzyski RG, Diamond MP, et al. Letrozole versus clomiphene for infertility in the polycystic ovary syndrome. N Engl J Med 2014;371(2):119-129.
Read the original paperSummarised by the Draxer Clinical Advisory Department for health professionals. It supports, and does not replace, clinical judgement.