Clomifene, a front-line infertility treatment in women with polycystic ovary syndrome (PCOS), is not very effective and comes with unpleasant side effects and a high rate of multiple pregnancies.
A study published in
New England Journal of Medicine
suggest that letrozole, an aromatase inhibitor, may be an effective alternative to clomifene, with potential advantages over standard therapy
Among 750 women with infertility caused by PCOS, cumulative live birth rates were 27.5% in those given letrozole versus 19.1% in those given clomifene (rate ratio 1.44). Ovulation, conception and pregnancy were all significantly more likely with letrozole, while rates of neonatal complications (including anomalies) and adverse events were similar.
 Legro RS et al. N Engl J Med 2014; 371:119–129.