Levonorgestrel 52 mg intrauterine device placement without uterine sounding: A feasibility study

To evaluate feasibility of levonorgestrel 52 mg intrauterine device (IUD) placement without uterine sounding.

We performed a three-phase feasibility study from February 2023-May 2024. In phase one, participants had levonorgestrel 52 mg IUD placement with sounding. In the experimental phases, placement occurred without sounding and with (phase two) or without (phase three) concurrent transabdominal sonography and participants had 3-month follow-up. We defined feasibility as successful IUD placement without uterine sounding based on ultrasound confirmation. We measured total instrumentation time from the sound or inserter touching the cervix to inserter removal. Participants reported maximal pain experienced using a 100-mm Visual Analog Scale when the inserter was removed. We calculated a sample size of 30 per phase so that if there was one failed placement, the lower 95% confidence interval of the successful placement rate would be no less than 90.0%.

Successful placement without sounding occurred in 30(100%) participants in phase two and 28(93.3%) in phase three. Median instrumentation was longest in phase one (49.5 [interquartile range (IQR) 42.3-55.0] seconds) compared to phases two (16.0 [IQR12.0-28.0] seconds, p < 0.0001) and three (25.0 [IQR 18.5-32.2] seconds, p < 0.0001). Participants' median placement pain was 21.0 (IQR 10.3-32.8) mm in phase one with no difference in phase two (25.5 [IQR 14.3-47.0] mm, p = 0.35), but was higher in phase three (36.0 [IQR 22.8, 61.0] mm, p = 0.01).

Levonorgestrel 52 mg IUD placement without sounding is feasible with concurrent sonography. Placement without sounding results in shorter instrumentation time but does not decrease maximum placement pain.