Comparing bleeding patterns for the levonorgestrel 52 mg, 19.5 mg, and 13.5 mg intrauterine systems

Compare bleeding patterns for levonorgestrel 52 mg, 19.5 mg, and 13.5 mg intrauterine system (IUS) products using the World Health Organization Belsey definitions.

We extracted available data on bleeding patterns from published sources. Lower dose products had published data at 1 and 3 years; the 52 mg IUS had available data for 1, 2 and 3 years for amenorrhea and 1 and 2 years for other bleeding patterns. We interpolated 2-year data for the lower dose products based on 1- and 3-year data and compared bleeding pattern rates using Fisher exact testing.

The studies evaluated bleeding patterns in 1700, 1566 and 1531 women using levonorgestrel 52 mg, 19.5 mg and 13.5 mg products, respectively. Amenorrhea rates were greater by 180 days after insertion for 52 mg IUS users (11%) as compared to 19.5 mg (5%, p<.0001) and 13.5 mg (3%, p<.0001). Infrequent bleeding rates were higher for 52 mg users by the end of year 1 (31%) compared to 19.5 mg (26%, p=.01) and 13.5 mg (20%, p<.0001). Irregular bleeding rates were higher with the lower dose products by 90 days after insertion with continued lower rates at the end of year 1 for 52 mg users (6%) compared 19.5 mg (17%, p<.0001) and 13.5 mg (23%, p<.0001). Frequent and prolonged bleeding patterns were similar over the first 2 years for all products, although the rates were statistically higher for levonorgestrel 13.5 mg IUS users compared to 19.5 mg and 52 mg IUS users (p≤.03 for all time points after 90-days post-insertion).

Levonorgestrel 52 mg IUS users have more amenorrhea and infrequent bleeding and less irregular bleeding compared to women using lower dose levonorgestrel IUS products.

All women considering levonorgestrel IUS placement should receive counseling on the differences in bleeding patterns related to the various available doses. Women who are interested in maximizing the likelihood of favorable bleeding should consider a levonorgestrel 52 mg IUS over the lower dose alternatives.