. 2016 Jan 29;5:38–47. doi: 10.1007/s13669-016-0140-8

Table 1.

Contraceptive efficacy in hormonal male contraception clinical trials

Study reference	Sperm concentration threshold million/ml	Drugs	Number enrolled	Number completing suppression phase (6 m)	Number reaching threshold	Number entering efficacy	Number completing efficacy	Number with sperm rebound	Years of exposure to risk of pregnancy	Pregnancies/failure rate^a
WHO 1990 [13]	Azoospermia	TE 200 mg/week	271	225 (83 %)	157 (70 %)	157	119	21 (1.4 %)	123.8	1
WHO 1990 [13]	Azoospermia	TE 200 mg/week	271	225 (83 %)	157 (70 %)	157	119	21 (1.4 %)	123.8	0.8 (0.0–45.)^a
WHO 1996 [14]	<3 (reduced form <5)	TE 200 mg/week	399	357 (89 %)	349 (97.8 %)	268	209	4 (0.2 %)	279.9 (230.4 azoospermia)	4
WHO 1996 [14]	<3 (reduced form <5)	TE 200 mg/week	399	357 (89 %)	349 (97.8 %)	268	209	4 (0.2 %)	279.9 (230.4 azoospermia)	1.4 (0.4–3.7)^a
McLachlan et al 2000 [15]	<1	T implants 800 or 1200 mg/4 months	36	29	21 (72 %)	16	17	4	17.8	0
Turner et al 2003 [19]	<1	T implants 800 mg/4–6 months DMPA 300 mg/3 months	55	55	53 (94 %)	51	30	0 with T implants/4 months	35.5	0 (0–8)^a
Gu et al 2003 [27]	<3	TU 1000 mg loading 500 mg/month	308	308	299 (97.1 %)	296	280	6 (2.3 %)	143	0
Gu et al 2003 [27]	<3	TU 1000 mg loading 500 mg/month	308	308	299 (97.1 %)	296	280	6 (2.3 %)	143	1 in sperm rebound 2.3 (0.5–4.2)^a
Gu et al 2009 [28••]	<1	TU 1000 mg loading 500 mg/month	1045	898	855 (95.2 %)	855	733	10 (1.3 %)	1554.1	9
Gu et al 2009 [28••]	<1	TU 1000 mg loading 500 mg/month	1045	898	855 (95.2 %)	855	733	10 (1.3 %)	1554.1	1.1 (0.4–1.8)^a
WHO/CONRAD 2015 [29•]	<1	TU 1000 mg and Net–EN 200 mg/8 weeks	320	283	274 (95.9 %)	266	111^b	6	?	4
										1.57 (0.59–4.14)
										2.18 (0.82–5.80)^a

T testosterone, TE testosterone enanthate, TU testosterone undecanoate, DMPA depo-medroxyprogesterone acetate, NET-EN norethisterone enanthate

^aPearl rate (95 % confidence interval) per 100 couple-year

^bTrial terminated before planned end of study