In this secondary analysis of the Contraceptive CHOICE Project, we included participants who had an LNG-IUS inserted within 1 month of enrollment and continued use for 12 months. Using 12-month telephone survey data, we defined amenorrhea at 12 months of use as no bleeding or spotting during the previous 6 months. We used chi-square and multivariable logistic regression to assess the association of baseline bleeding pattern with amenorrhea while controlling for confounding variables.
Of 1802 continuous 12-month LNG-IUS users, amenorrhea was reported by 4.9%, 14.8% and 15.4% of participants at 3, 6 and 12 months, receptively. Participants with light baseline bleeding or short duration of flow reported higher rates of amenorrhea at 3 and 6 months postinsertion (p<.03), while LNG-IUS users with heavy or prolonged flow were less likely to report amenorrhea at 3 and 6 months (p<.03). In a multivariable analysis, participants with self-reported heavy bleeding at baseline were less likely to report amenorrhea at 12 months than those who reported moderate bleeding (ORadj, 0.36; 95% CI, 0.16–0.69).
Women with heavier menstrual bleeding are less likely than women with moderate flow to report amenorrhea following 12 months of LNG-IUS use.
Baseline heavy menstrual flow reduces the likelihood of amenorrhea with LNG-IUS use, information that could impact contraceptive counseling. Anticipatory counseling can improve method satisfaction and continuation, an important strategy to continue to reduce unintended pregnancy and abortion rates.