OBJECTIVES: Compare pregnancy rates post-initiation of 84/7 (84 days levonorgestrel/ethinyl estradiol (EE) 0.15mg/0.03mg tablets plus EE 0.01mg or placebo for 7 days or 84 days levonorgestrel/ethinyl estradiol [EE] 0.1mg/0.02mg tablets plus EE 0.01mg for 7 days) to use of 21/7 (21 days combined EE/progestin plus 7 days placebo) or 24/4 (24  days EE/progestin plus 4 days placebo) oral contraceptive regimens over the course of 1 year. METHODS: Data for this study were obtained from the US i3 InvisionTM database from May 2009 through December 2011. Patients were included if they received the medication of interest (first use=index date), were age 15-40 on index date, and had continuous insurance coverage from index date through 1 year post index date. The 84/7 EE cohort was matched 2:1 without replacement to the 84/7 placebo cohort based upon age, sex, region, business type of insurance, insurance product and year of index date. Differences in pregnancy rates in the 1 year post index date were compared using a chi-square statistic.  RESULTS: There were 12,923  individuals in the 84/7  EE cohort and 1,276  individuals in the 84/7 placebo cohort. Matching resulted in a final sample of 3,732 (2,488 in the 84/7 EE cohort and 1,244 in the 84/7 placebo cohort) for a successful match rate of 97.5%.  Patients in the matched cohort had a mean age of 26.98 years (SD=7.56), resided predominantly in the South (55.55%) or Midwest (21.14%) and were most commonly insured with point of service insurance (80.47%) or an exclusive provider organization (12.94%).  Pregnancy rates in the 1 year post-initiation on an OC were found to be statistically significantly lower for initiators of 84/7 EE compared with 84/7 placebo (3.01% v 4.50%; P=0.0200).  CONCLUSIONS: Pregnancy rates were significantly lower in women using a 84/7 EE OC regimen compared with a 84/7 placebo regimen.