For a study, researchers sought to evaluate the incidence rates of ectopic pregnancy by contraceptive technique in a cohort of women who used hormonal contraception between 2005 and 2016. Women between the ages of 15 and 49 who had a filled prescription for hormonal contraception in the Prescribed Drug Register between 2005 and 2016 were included in the study. All exposed woman-years for each woman were assigned to treatment episodes based on the form of contraception used. The treatment period began on the day the prescription was filled and concluded on the first day of the supply’s end, with new eligible dispensing pregnancy-related diagnosis and its associated projected last menstrual cycle, or removal procedure. Ectopic pregnancy was defined as at least two records of International Classification of Diseases, Tenth Revision code O00- within 30 days, including O00.0, O00.1, O00.2, O00.8, O00.9, or one episode of O00- and one surgical operation for ectopic pregnancy (NOMESCO Classification of Surgical Procedures code LBA, LBC, LBD, LBE, LBW). For each form of contraception, the incidence rates per 1,000 woman-years and 95% CIs were determined.
There were 1,663,242 women in the research, and there were 1,915 ectopic pregnancy incidents. The incidence rate (95% CI) of ectopic pregnancy was estimated to be 2.76 (2.26–3.35) per 1,000 woman-years for 13.5-mg LNG hormonal intrauterine device (IUD); 0.30 (0.28–0.33) per 1,000 woman-years for 52-mg LNG hormonal IUD; 0.20 (0.19–0.22) per 1,000 woman-years for combined oral contraception; 0.31 (0.26–0.37) per 1,000 woman-years for progestogen implants, 0.31 (0.26–0.37) per 1,000 woman-years; oral medium-dose progestogen (desogestrel 75 mg), 0.24 per 1,000 woman-years, (0.21–0.27); and oral low-dose progestogen (norethisterone 0.35 mg and lynestrenol 0.5 mg), 0.81 (0.70–0.93) per 1,000 woman-years.
The use of hormonal contraception significantly reduced the chance of an ectopic pregnancy. Ectopic pregnancy was much more common in women who used a low-dose hormonal IUD (13.5 mg LNG) than in women who used other kinds of hormone contraception. The study provided real-world evidence to help guide optimal clinical practice for women-centered contraception counseling.