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Continuous Oral Contraceptives (COCs): Are Bleeding Patterns Dependent on the Hormones Given?

This study has been completed.
Information provided by:
Oregon Health and Science University Identifier:
First received: July 12, 2005
Last updated: July 18, 2005
Last verified: July 2005
While there may be a decrease in the total number of bleeding days women experience with continuous-dosed COCs (no menstrual withdrawal week), these regimens frequently result in an increased number of “breakthrough” or non-scheduled bleeding days. Breakthrough bleeding is among the main reasons cited for discontinuation of combined COCs dosed traditionally (3 weeks of active pill, 1 week of placebo) or continuously, and may offset the perceived benefit of fewer withdrawal bleeding events for many women taking continuous-dosed COCs. The exact mechanisms responsible for breakthrough bleeding patterns during hormonal contraception are unknown and may be related to the pill formulation. This study is to determine whether progestin type or estrogen dose influences bleeding patterns, side effects, or satisfaction with combined oral contraceptives (COC) dosed continuously.

Condition Intervention
Breakthrough Bleeding Drug: Birth control pills

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: Double-Blind
Primary Purpose: Prevention

Resource links provided by NLM:

Further study details as provided by Oregon Health and Science University:

Primary Outcome Measures:
  • Bleeding patterns

Secondary Outcome Measures:
  • Satisfaction, menstrual-associated symptoms

Estimated Enrollment: 160
Estimated Study Completion Date: August 2004

Ages Eligible for Study:   18 Years to 49 Years   (Adult)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Age > 18 to 49 years old
  • Good general health
  • No medical contraindications to combined COC therapy.
  • In addition, all participants were required to have taken cyclic COCs for at least three months at the time of enrollment, in order to avoid common transition bleeding with the initiation of COCs.
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Please refer to this study by its identifier: NCT00120913

United States, Oregon
Portland, Oregon, United States, 97239
Sponsors and Collaborators
Oregon Health and Science University
Principal Investigator: Alison B Edelman, MD, MPH Oregon Health and Science University
  More Information Identifier: NCT00120913     History of Changes
Other Study ID Numbers: OHSU IRB 7198
Study First Received: July 12, 2005
Last Updated: July 18, 2005

Keywords provided by Oregon Health and Science University:
Breakthrough bleeding while taking continuously dosed oral contraceptives

Additional relevant MeSH terms:
Pathologic Processes
Uterine Hemorrhage
Uterine Diseases
Genital Diseases, Female
Contraceptive Agents
Contraceptives, Oral
Contraceptives, Oral, Combined
Reproductive Control Agents
Physiological Effects of Drugs
Contraceptive Agents, Female processed this record on July 26, 2017