1 00:00:00,911 --> 00:00:02,475 When I tell people 2 00:00:02,475 --> 00:00:07,177 that I'm trying to develop a contraceptive pill for men, 3 00:00:07,177 --> 00:00:10,656 the response usually varies along gender lines. 4 00:00:11,440 --> 00:00:13,027 Women say something like, 5 00:00:13,027 --> 00:00:16,257 "Fantastic. It's about time. When?" 6 00:00:16,257 --> 00:00:17,927 (Laughter) 7 00:00:17,927 --> 00:00:20,098 Men have one of two responses. 8 00:00:20,098 --> 00:00:21,833 They either love the idea, 9 00:00:21,833 --> 00:00:24,126 or they look at me a little warily 10 00:00:24,126 --> 00:00:28,166 and wonder what exactly I have in store for their testicles. 11 00:00:28,166 --> 00:00:30,540 (Laughter) 12 00:00:30,540 --> 00:00:34,384 So why does the world need a male pill? 13 00:00:35,296 --> 00:00:37,131 Well, what if I told you 14 00:00:37,131 --> 00:00:41,606 that of the six million pregnancies annually in the United States, 15 00:00:41,606 --> 00:00:44,482 three million of them are unintended? 16 00:00:44,482 --> 00:00:46,189 That's half. 17 00:00:46,189 --> 00:00:48,341 That's a really surprising number, 18 00:00:48,341 --> 00:00:50,995 and those three million unintended pregnancies 19 00:00:50,995 --> 00:00:54,200 account for the vast majority of the more than one million abortions 20 00:00:54,200 --> 00:00:56,947 annually performed in the United States. 21 00:00:56,947 --> 00:01:01,993 Happily, the rate of unintended pregnancy has fallen in the last few years 22 00:01:01,993 --> 00:01:03,953 by about 10 percent. 23 00:01:03,953 --> 00:01:06,782 This is because more women are using effective, long-acting, 24 00:01:06,782 --> 00:01:08,858 reversible forms of contraception. 25 00:01:09,842 --> 00:01:13,291 But we still have a long way to go. 26 00:01:13,291 --> 00:01:16,779 One approach that's finally becoming a real possibility 27 00:01:16,779 --> 00:01:20,099 is better contraceptive options for men. 28 00:01:20,099 --> 00:01:21,944 Think about it. 29 00:01:21,944 --> 00:01:25,898 We have over a dozen methods of contraception for women: 30 00:01:25,898 --> 00:01:31,361 pills, patches, IUDs, shots, sponges, rings, etc. 31 00:01:32,436 --> 00:01:36,280 For men, we've had the same two options 32 00:01:36,280 --> 00:01:37,820 for more than a hundred years: 33 00:01:37,820 --> 00:01:40,035 condoms and vasectomy. 34 00:01:40,735 --> 00:01:42,990 Despite having only two options, 35 00:01:42,990 --> 00:01:45,679 both of which have significant drawbacks, 36 00:01:45,679 --> 00:01:50,021 men currently account for 30 percent of all contraceptive use, 37 00:01:50,021 --> 00:01:52,963 with 10 percent of couples relying on vasectomy 38 00:01:52,963 --> 00:01:55,710 and 20 percent of couples using condoms. 39 00:01:56,976 --> 00:02:01,890 Why are 20 percent of couples relying on condoms for contraception 40 00:02:01,890 --> 00:02:05,727 when condoms have a one-year failure rate of over 15 percent? 41 00:02:06,202 --> 00:02:09,272 It's because many women can't either safely take 42 00:02:09,272 --> 00:02:12,789 currently available female contraceptives for reasons such as blood clots, 43 00:02:12,789 --> 00:02:15,035 or they can't tolerate the side effects. 44 00:02:16,487 --> 00:02:20,339 So if we think a male contraceptive would be useful, the next question is, 45 00:02:20,339 --> 00:02:23,183 how do we go about developing one? 46 00:02:23,183 --> 00:02:25,953 Well, there's two general approaches. 47 00:02:25,953 --> 00:02:29,910 The first approach is to try and interfere with the way the sperm swim towards 48 00:02:29,910 --> 00:02:31,791 or bind to the egg. 49 00:02:31,791 --> 00:02:34,992 This approach turns out to be really difficult, 50 00:02:35,405 --> 00:02:39,452 because it's hard to get enough medication in the small volume of the ejaculate 51 00:02:39,452 --> 00:02:43,242 and have it still work inside the female reproductive tract. 52 00:02:43,854 --> 00:02:47,571 This is why there's been a lot more work done on the second approach, 53 00:02:47,571 --> 00:02:51,811 which is turning off sperm production entirely. 54 00:02:51,811 --> 00:02:53,512 This is also challenging. 55 00:02:53,512 --> 00:02:57,970 Why? Turns out that men make a lot of sperm. 56 00:02:57,970 --> 00:03:03,668 Men make a thousand sperm every second, 57 00:03:03,668 --> 00:03:06,035 and to have an effective contraceptive, 58 00:03:06,035 --> 00:03:08,657 you need to get that level of sperm production 59 00:03:08,657 --> 00:03:11,887 down to one percent of its normal value. 60 00:03:11,887 --> 00:03:14,685 The good news is, this is possible, 61 00:03:14,685 --> 00:03:16,152 almost. 62 00:03:16,152 --> 00:03:22,174 The most studied approach has been to use hormones to suppress sperm production. 63 00:03:22,174 --> 00:03:25,465 Testosterone and progesterone, when administered together, 64 00:03:25,465 --> 00:03:29,692 will suppress the signals from the brain to the testes to make sperm, 65 00:03:29,692 --> 00:03:31,758 and in about 90 percent of men, 66 00:03:31,758 --> 00:03:36,020 sperm production after three to four months will stop. 67 00:03:36,020 --> 00:03:39,646 Unfortunately, 10 percent of men don't respond to these hormonal regimens 68 00:03:39,646 --> 00:03:42,926 for reasons that aren't understood. 69 00:03:42,926 --> 00:03:45,678 For the last several years, my colleagues and I 70 00:03:45,678 --> 00:03:48,928 have been taking a different approach to male contraceptive development, 71 00:03:48,928 --> 00:03:52,085 one that doesn't involve the administration of hormones. 72 00:03:52,085 --> 00:03:58,019 Specifically, we are looking to block the function of Vitamin A in the testes. 73 00:03:58,019 --> 00:04:01,255 Why? Well, for over 90 years it's been known 74 00:04:01,255 --> 00:04:04,381 that you need Vitamin A to make sperm. 75 00:04:04,381 --> 00:04:07,477 Animals who are deprived of Vitamin A in their diet 76 00:04:07,477 --> 00:04:08,988 stop making sperm 77 00:04:08,988 --> 00:04:14,051 and restart making sperm again when the Vitamin A is reintroduced. 78 00:04:14,051 --> 00:04:16,402 The Vitamin A that we ingest 79 00:04:16,402 --> 00:04:21,393 is converted by a family of enzymes to something called retinoic acid. 80 00:04:21,393 --> 00:04:25,435 One of these enzymes is found only in the testes. 81 00:04:25,435 --> 00:04:28,500 It's this enzyme that we are attempting to block. 82 00:04:28,500 --> 00:04:32,634 The blockade of this enzyme should provide the testes of retinoic acid 83 00:04:32,634 --> 00:04:34,915 and stop sperm production 84 00:04:34,915 --> 00:04:38,996 without affecting Vitamin A's functions elsewhere in the body. 85 00:04:38,996 --> 00:04:40,784 We're testing this approach in animals, 86 00:04:40,784 --> 00:04:43,582 and hope to move to human testing soon. 87 00:04:44,809 --> 00:04:48,580 Obviously, the impact of such a male contraceptive 88 00:04:48,580 --> 00:04:51,712 would go well beyond reproductive biology. 89 00:04:51,712 --> 00:04:54,314 It's interesting to speculate about the effect that it would have 90 00:04:54,314 --> 00:04:57,614 on relationships between men and women. 91 00:04:57,614 --> 00:04:59,131 One intriguing possibility 92 00:04:59,131 --> 00:05:03,980 is that a man could monitor his contraceptive status over time. 93 00:05:03,980 --> 00:05:05,587 In the last several years, 94 00:05:05,587 --> 00:05:09,852 two groups have introduced home sperm-testing devices 95 00:05:09,852 --> 00:05:11,311 that are iPhone-based 96 00:05:11,311 --> 00:05:13,297 and that are easy to use. 97 00:05:13,297 --> 00:05:18,214 A man could test his sperm count and share the result with his partner. 98 00:05:18,478 --> 00:05:20,186 If the man's sperm count were zero, 99 00:05:20,186 --> 00:05:22,844 the man and his partner would feel very comfortable 100 00:05:22,844 --> 00:05:25,753 relying on his contraceptive. 101 00:05:25,753 --> 00:05:28,771 A tool like this, coupled with a male contraceptive, 102 00:05:28,771 --> 00:05:33,409 could greatly increase the role for men in preventing unintended pregnancy. 103 00:05:35,086 --> 00:05:37,976 The researchers who are working on male contraception 104 00:05:37,976 --> 00:05:40,792 are trying to create a better future for couples, 105 00:05:40,792 --> 00:05:43,470 a future where contraception is no longer considered just "a woman's issue," 106 00:05:43,470 --> 00:05:49,013 rather an issue for couples to decide together. 107 00:05:49,013 --> 00:05:52,645 So why does the world need a male pill? 108 00:05:52,645 --> 00:05:55,522 Well I believe that a male pill 109 00:05:55,522 --> 00:06:00,084 will help reduce the stubbornly high rates of unintended pregnancy and abortion 110 00:06:00,084 --> 00:06:02,896 and allow men to equally participate 111 00:06:02,896 --> 00:06:04,908 in contraception. 112 00:06:04,908 --> 00:06:07,682 Thank you. 113 00:06:07,682 --> 00:06:10,474 (Applause)