The effects of Implanon on menstrual bleeding patterns.

Objectives To evaluate an integrated analysis of bleeding patterns associated with use of the subdermal contraceptive implant Implanon® (etonogestrel, Organon, part of Schering-Plough) and to provide physician guidance to optimize patient counselling.Methods Data from 11 clinical trials were reviewed (N = 923). Assessments included bleeding-spotting records, dysmenorrhoea, and patient-perceived reasons for discontinuation. Bleeding patterns were analysed via reference period (RP) analyses.Results Implanon® use was associated with the following bleeding irregularities: amenorrhoea (22.2%) and infrequent (33.6%), frequent (6.7%), and/or prolonged bleeding (17.7%). In 75% of RPs, bleeding-spotting days were fewer than or comparable to those observed during the natural cycle, but they occurred at unpredictable intervals. The bleeding pattern experienced during the initial phase predicted future patterns for the majority of women. The group of women with favourable bleeding patterns during the first three mont...