TABLE 5. Estimated Relative Risk (95% Confidence Interval) of Myocardial Infarction and Ischemic Stroke in Current Oral Contraceptive Users According to Progestin Type: Studies Since 1994

		Myocardial Infarction Progestin				Ischemic Stroke Progestin
Place/Study	Reference	Gestodene/Desogestrel	Levonorgestrel	Norethindrone/Lynestrenol	Reference	Gestodene/Desogestrel	Levonorgestrel	Norethindrone/Lynestrenol
England, Scotland, Wales/MICA study	31	2.0 (0.9–4.4)	1.0 (0.5–2.2)	2.3 (0.2–32.2)^*		Not studied	—	—
Netherlands/RATIO study	32	1.3 (0.7–2.5)	2.5 (1.5–4.1)	2.7 (1.0–7.3)^*	36	2.3 (1.3–4.2)	2.1 (1.3–3.3)	1.8 (0.7–4.7)
Europe/transnational	33	1.1 (0.4–3.4)	3.0 (1.5–6.1)	NR	37	3.1 (1.9–5.0)	3.1 (1.9–5.0)	NR
Western United States/KPSC/Seattle	34	No data	0.9 (0.2–6.6)	1.0 (0.4–2.9)	38	No data^†	1.0 (0.3–3.6)	1.1 (0.5–2.3)
WHO (all centers)	35	1.0 (0.1–7.0)	1.6 (0.5–5.4)	NR	44	1.8 (0.6–5.2)	2.7 (1.8–4.1)
European centers								NR
Developing country centers					39			5.2 (0.9–30.6)

KPSC, Kaiser Permanente Southern California; MICA, Myocardial Infarction Causality; NR, not reported; RATIO, Risk of Arterial Thrombosis in Relation to Oral Contraceptives; WHO, World Health Organization.
^*Includes formulations with 50+ μg of ethinyl estradiol.
^†No data,.