Frequency of same-day contraceptive initiation, recent unprotected intercourse, and pregnancy risk: a prospective cohort study of multiple contraceptive methods

Abstract

BackgroundSame-day start removes barriers to contraceptive initiation and may reduce the risk of unintended pregnancy. Same-day start may be appropriate for all contraceptive methods, but we lack data comparing methods. ObjectivesTo assess the frequency of same-day initiation among six contraceptive methods selected for “same-day start” among new contraceptive users and describe the efficacy of same-day start first cycle pregnancy risk by all contraceptive methods and by each method. Study DesignUsing prospective data from the HER Salt Lake Contraceptive Initiative, we identified and assessed outcomes for participants initiating a new method of contraception beyond the first seven days of their menstrual cycle (same-day start). Enrolled participants at four family planning clinics in Salt Lake County, Utah between September 2015-March 2017 received their method of choice regardless of their cycle day or recent unprotected intercourse. All participants self-reported last menstrual period data and unprotected intercourse events in the previous 2 weeks. We excluded participants that received care immediately after or within two weeks of abortion care. Clinical electronic health records provided information on contraceptive method initiation and use of oral emergency contraception. Participants reported pregnancy outcomes in 1-, 3-, and 6-month follow-up surveys with clinic verification to identify any pregnancy resulting from same-day initiation. The primary outcomes report the frequency of same-day start use and first cycle pregnancy risk among same-day start users of all contraceptive methods. The secondary outcomes include frequency of and pregnancy risk in the first cycle of use among same-day start contraception users by method. We also report frequency of unprotected intercourse within 5 days and 6-14 days of contraception initiation, frequency of concomitant receipt of oral emergency contraception with initiation of ongoing contraception, and pregnancy risk with these exposures. We analyzed pregnancy risk by contraceptive method initiated same-day and assessed for simultaneous use of oral emergency contraception. ResultsOf the 3,568 individuals enrolled, we identified the majority as same-day start users (n=2,575/3,568, 72.2%), with one in eight of those reporting unprotected intercourse in the previous 5 days (n=322/2,575, 12.5%) and one in ten reporting unprotected intercourse 6-14 days prior to contraceptive method initiation (n=254/2,575, 9.9%). We identified 11 pregnancies among same-day start users (0.4%, 95% CI 0.2%-0.7%) compared to 1 (0.1%. 95% CI 0.002%-0.6%) among those who initiated contraception within seven days from the last menstral period. Users of oral hormonal contraception and vaginal hormonal methods reported the highest 1st cycle pregnancy rates (1.0 – 1.2%). Among same-day start users, 174 (6.8%) received oral emergency contraception at enrollment in conjunction with another method. Of the same-day user who received emergency contraception at initiation, 4 (2.3%) pregnancies were reported. Conclusion(s)Same-day start is common and associated with a low pregnancy risk. Using the “any method, any-time” approach better meets contraceptive clients’ needs and maintains a low risk of pregnancy.