Short-term, low-dose, non-steroidal anti-inflammatory drug application diminishes premature ovulation in natural-cycle IVF.

A retrospective cohort study was conducted in a private infertility centre to evaluate the use of non-steroidal antiinflammatory drugs (NSAID) in natural-cycle IVF (nIVF) treatment. A total of 1865 first-rank nIVF cycles performed during 2009–2010 were evaluated. Low-dose, post-trigger NSAID was administered in a non-randomized way in cycles at higher ovulation risk where an imminent LH surge was detected on triggering day. Main outcome measures were premature ovulation rate, embryo transfer rate per scheduled cycle and clinical pregnancy and live birth rates per embryo transfer. NSAID use was associated with a significantly lower risk of premature ovulation (3.6% versus 6.8%, adjusted OR 0.24, 95% CI 0.15–0.39, P < 0.0001) and higher embryo transfer rate (46.8% versus 39.5%, adjusted OR 1.38, 95% CI 1.06–1.61, P = 0.012) per scheduled cycle. Clinical pregnancy (39.1% versus 35.9%) and live birth rates per embryo transfer (31.3% versus 31.4%) were comparable. In this retrospective series, short-term low-dose NSAID application positively influenced nIVF cycles by diminishing the rate of unwanted premature ovulations and increasing the proportion of cycles reaching embryo transfer.