Medication adherence and treatment success in the National Institute of Child Health and Human Development–Reproductive Medicine Network's Pregnancy in Polycystic Ovary Syndrome Trial

We investigated whether poor adherence with metformin tablets may have contributed to the poor success rates seen in the metformin-containing arms of the Pregnancy in Polycystic Ovary Syndrome (PPCOS) Trial. Median adherence for both metformin and clomiphene citrate tablets was within acceptable limits and unrelated to ovulation: thus, failure to comply with physician recommendations for metformin dosing was not the reason for low ovulation and pregnancy rates in the PPCOS Trial.