Adding low-dose estrogen to the hormone-free interval: impact on bleeding patterns in users of a 91-day extended regimen oral contraceptive.
BACKGROUND
A cross-study analysis of contraceptive clinical trials for two different 91-day oral contraceptive (OC) regimens was performed to examine the impact on bleeding patterns when supplementing the 7-day hormone-free interval with 10 mcg ethinyl estradiol (EE) daily.


METHODS
Two separate 1-year Phase 3 clinical programs were conducted using similar study designs. The percentages of subjects reporting bleeding and spotting using electronic diaries for each 91-day cycle were compared.


RESULTS
Scheduled bleeding with the EE regimen was less than that reported with the regimen utilizing placebo during Days 85-91, with significant differences noted for all four 91-day cycles. Unscheduled bleeding decreased more quickly with the 91-day regimen containing low-dose EE in place of placebo, with significant differences noted during the third cycle.


CONCLUSIONS
This cross-study comparison suggests that the administration of low-dose estrogen in place of placebo in a 91-day extended regimen OC improves the bleeding profile.
Kaunitz
Andrew M
AM
Department of Obstetrics and Gynecology, University of Florida College of Medicine-Jacksonville, Jacksonville, FL 32209, USA.
Portman
David J
DJ
Hait
Howard
H
Reape
Kathleen Z
KZ