Continuous versus cyclic use of combined oral contraceptives for contraception: systematic Cochrane review of randomized controlled trials

BACKGROUND: With the recent US Food and Drug Administration approval of a combination oral contraceptive that causes a withdrawal bleed every 3 months instead of monthly, avoidance of menstruation through extended or continuous administration (> 28 days of active pills) of combined oral contraceptives may become more commonplace for reasons of personal preference rather than limited to treatment of menstrual-associated medical disorders. METHODS: The review aimed to compare contraceptive efficacy, compliance, continuation, satisfaction, bleeding profiles, and menstrual symptoms of combined oral contraceptives with continuous dosing (> 28 days of active pills) versus traditional cyclic dosing (21 days of active pills and 7 days of placebo). We searched five computerized databases as well as reference lists of relevant articles for randomized controlled trials (RCT) using continuous or extended combined oral contraceptives for contraception. Two reviewers independently extracted data from eligible articles. RESULTS: Six RCT met inclusion criteria and were of good quality. Contraceptive efficacy and compliance were similar between groups. Discontinuation overall, and for bleeding problems, was not uniformly higher in either group. When studied, participants reported high satisfaction with both dosing regimens. Five out of the six studies found that bleeding patterns were either equivalent or improved with continuous-dosing regimens. The continuous-dosing group had greater improvement of menstrual-associated symptoms (headaches, genital irritation, tiredness, bloating, and menstrual pain). CONCLUSIONS: The variations in pill type and time-interval for continuous dosing make direct comparisons between regimens unfeasible. To allow for comparisons, future studies should choose a previously researched pill and dosing regimen. More attention needs to be directed towards participant satisfaction and menstruation-associated symptoms.