Outcomes
In this study we distinguish between use of the original IUD at 6 weeks, 3 months and 6 months, and use of any IUD which includes replacement IUDs.
In the absence of core outcome sets for IUD insertion, our main outcomes were 1) use of the original IUD, and 2) use of any IUD at the end of the 6-week follow-up period.
Use of the IUD was defined as an adequately placed IUD without clinical indication for removal. We determined that the IUD was adequately placed if it had a fundal or intrauterine location on ultrasound examination and did not cause symptoms that warranted removal. If any part of the IUD was visible in the cervix it was considered intracervical and removed. IUDs with an intrauterine malposition (>2 cm from the fundal endometrium) associated with symptoms of pain or abnormal discharge, were removed. If the IUD was absent upon ultrasound, and the woman had not noticed it falling out, she was referred for an abdominal x-ray to rule out perforation and intra-abdominal location.
Our secondary outcomes were rates of complete expulsion, intracervical location, and symptomatic malposition at 6 weeks, use of any IUD at 3 and 6 months, most effective contraception used at 3 and 6 months, cramping and bleeding at 3 and 6 months, pain on insertion, preference for immediate or delayed insertion, satisfaction with the IUD, planned duration of IUD use, and recurrent pregnancy within 6 months.