TABLE 1.

Pregnancy Data Among LNG- and ENG-Releasing Subdermal Implant Users Through 5 Years of Use From Ali et al., 2016¹⁸

	LNG-Releasing Implant				ENG-Releasing Implant
	Years 1–3^a	Year 4^a	Year 5	Years 1–5 (Cumulative)	Years 1–3^a	Year 4^a	Year 5	Years 1–5 (Cumulative)
No. of women	997	470	330		995	311	204
Woman-months of observation	28670	6,254	4,629	30,325	28786	4,606	2,454	22,044
No. of pregnancies	3^b	0	0	3	3^b	0	0	3
Cumulative pregnancy rates per 100 woman-years^c (95% CI)	0.4 (0.1–1.4)		0.8 (0.2, 2.3)		0.4 (0.1–1.4)			0.6 (0.2, 1.8)

Abbreviations: CI, confidence interval; ENG, etonogestrel; LNG, levonorgestrel.
↵a Cut-off for 3 years was at 38 months post-insertion while year-4 data started at 36 months post-insertion, resulting in a 2-month overlap in data. Woman-months of observation between these 2 time periods, however, is not additive.
↵b Pregnancy data from the first 3 years reported in Bahamondes et al., 2015.²²
↵c Kaplain-Meier rates.