The anchor of the frameless intrauterine device does not migrate over time: an analysis in over 300 women

Abstract

Dirk Wildemeersch,1 Ansgar Pett,2 Sohela Jandi,2 Kilian Nolte,3 Wolfgang Albrecht4 1Gynecological Outpatient Clinic and IUD Training Centre, Ghent, Belgium; 2Gynecological Outpatient Clinic, Berlin, Germany; 3Gynecological Outpatient Clinic, Uetze, Germany; 4Gynecological Outpatient Clinic, Feldkirchen, Austria Objective: To evaluate the correct position of the anchor at insertion and follow-up and assess if migration of the anchor occurs over time. Materials and methods: This was an insertion-related, prospective, postmarketing study in 309 women. Following insertion, women were followed up at 4–6 weeks, 6 months, and yearly thereafter. The position of the visualized anchor in the fundus of the uterus was evaluated using ultrasound by measuring its distance from the serosal surface of the uterus (SA-distance). Results: A total of 309 parous (n=115) and nulliparous (n=194) women were fitted with the frameless GyneFix 200 or the GyneFix 330 intrauterine device for contraception. The mean SA-distance in 306 parous and nulliparous women was 6.0 mm (range 2.0–24.0 mm) at insertion in the parous group and 5.4 mm (range 1.3–11.0 mm) in the nulliparous group. At the first follow-up in 281 women, the SA-distance was 6.0 mm (range 2.0–12.0 mm) in the parous group and 5.5 mm (range 1.1–11.0 mm) in the nulliparous group. The SA-distance was not significantly different. One patient had an exceptionally large SA-distance of 24 mm, probably due to insertion in the posterior wall. No follow-up could be done in this patient. In 77 women, the SA-distance was measured up to 42 months. The mean SA-distance at insertion in the parous group was 5.2 mm (range 3.0–8.5 mm) and 4.8 mm (range 1.3–7.0 mm) in the nulliparous group. At the last follow-up up to 36 months or longer, the SA-distance was 5.1 mm (range 3.0–8.5 mm) in the parous group and 4.9 mm (range 1.3–7.0 mm) in the nulliparous group. The SA-distance was not significantly different. The visualized anchor was highly visible on ultrasound in all cases. Conclusion: The visualized anchor is a key element in the optimization of frameless technology, with the aim of allowing the provider to check its placement at insertion and at follow-up, which enhances provider confidence and assurance. The authors recommend measuring the thickness of the fundus prior to inserting the frameless intrauterine device and to measure the distance between the serosa and the visualized anchor following insertion and at the first follow-up examination. Keywords: frameless IUD, anchoring technology, visualization