Background: The CONSORT checklist and statement, adopted by medical journals for instructing authors reporting randomized controlled trials (RCTs), clearly indicate that results should not be reported solely as pvalues. Confidence interval (CI) and number needed to treat (NNT) are important items that must be reported in the results of RCTs. Objectives: To assess the rate of reporting CI and NNT in the results of RCTs in obstetrics and gynecology and to test a modified CONSORT checklist to improve reporting of CI and NNT. Methods: MEDLINE and EMBASE were searched for RCTs in obstetrics and gynecology in the last 10 years in 15 high impact journals. The percentage of RCTs reporting CI and NNT were calculated and compared. The CONSORT checklist was modified and authors of 20 RCTs were asked to submit the results after referring to the modified checklist. The modified checklist included an explicit instruction in the results section to report CI (in text and as a separate column in tables) and to report NNT. Results: The search identified 3152 RCTs in the last 10 years in 15 high impact journals. The rate of reporting CI was 513/3152 (16%) and 23/3162 ( > 1%) for NNT. There was a positive significant correlation between the impact factor and reporting CI (r=0.646, 95% CI 0.175 to 0.876, p=0.013) and NNT (r=0.592, 95% CI 0.0895 to 0.854, p=0.026). In the experimental study, the 20 authors contacted to use the modified CONSORT checklist, a pre-modification reporting of CI was 3/20 (15%) and none reporting NNT. After using the modified checklist, all authors reported CI and NNT. Conclusions: Authors are still reluctant to report CI and NNT. A modification of the CONSORT checklist seems to ensure a consistent reporting of results of RCTs in a more informative way.