TEDMED 2017
John Amory: How a male contraceptive pill could work
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Andrologist John Amory is developing innovative male contraception that gives men a new option for taking responsibility to prevent unintended pregnancy. He details the science in development -- and why the world needs a male pill.
John Amory - Male reproductive health expert
John Amory is leading research into novel options for male contraception, male infertility and hypergonadism. Full bio
John Amory is leading research into novel options for male contraception, male infertility and hypergonadism. Full bio
Double-click the English transcript below to play the video.
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When I tell people
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that I'm trying to develop
a contraceptive pill for men,
a contraceptive pill for men,
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the response usually varies
along gender lines.
along gender lines.
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Women say something like,
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"Fantastic. It's about time. When?"
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(Laughter)
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Men have one of two responses.
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They either love the idea,
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or they look at me a little warily
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and wonder what exactly
I have in store for their testicles.
I have in store for their testicles.
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(Laughter)
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So why does the world need a male pill?
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Well, what if I told you
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that of the six million pregnancies
annually in the United States,
annually in the United States,
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three million of them are unintended?
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That's half.
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That's a really surprising number.
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And those three million
unintended pregnancies
unintended pregnancies
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account for the vast majority
of the more than one million abortions
of the more than one million abortions
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annually performed in the United States.
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Happily, the rate of unintended pregnancy
has fallen in the last few years
has fallen in the last few years
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by about 10 percent.
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This is because more women
are using effective, long-acting,
are using effective, long-acting,
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reversible forms of contraception.
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But we still have a long way to go.
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One approach that's finally
becoming a real possibility
becoming a real possibility
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is better contraceptive options for men.
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Think about it.
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We have over a dozen methods
of contraception for women:
of contraception for women:
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pills, patches, IUDs,
shots, sponges, rings, etc.
shots, sponges, rings, etc.
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For men, we've had the same two options
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for more than a hundred years:
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condoms and vasectomy.
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Despite having only two options,
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both of which have significant drawbacks,
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men currently account
for 30 percent of all contraceptive use,
for 30 percent of all contraceptive use,
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with 10 percent of couples
relying on vasectomy
relying on vasectomy
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and 20 percent of couples using condoms.
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Why are 20 percent of couples
relying on condoms for contraception
relying on condoms for contraception
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when condoms have a one-year
failure rate of over 15 percent?
failure rate of over 15 percent?
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It's because many women
can't either safely take
can't either safely take
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currently available female contraceptives,
for reasons such as blood clots,
for reasons such as blood clots,
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or they can't tolerate the side effects.
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So if we think a male contraceptive
would be useful, the next question is:
would be useful, the next question is:
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How do we go about developing one?
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Well, there's two general approaches.
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The first approach is to try and interfere
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with the way the sperm
swim towards or bind to the egg.
swim towards or bind to the egg.
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This approach turns out
to be really difficult,
to be really difficult,
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because it's hard to get enough medication
in the small volume of the ejaculate
in the small volume of the ejaculate
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and have it still work inside
the female reproductive tract.
the female reproductive tract.
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This is why there's been a lot more work
done on the second approach,
done on the second approach,
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which is turning off
sperm production entirely.
sperm production entirely.
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This is also challenging.
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Why? Turns out
that men make a lot of sperm.
that men make a lot of sperm.
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(Laughter)
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Men make a thousand sperm every second
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and to have an effective contraceptive,
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you need to get that level
of sperm production
of sperm production
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down to one percent of its normal value.
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The good news is, this is possible,
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almost.
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The most studied approach has been to use
hormones to suppress sperm production.
hormones to suppress sperm production.
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Testosterone and progesterone,
when administered together,
when administered together,
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will suppress the signals from the brain
to the testes to make sperm,
to the testes to make sperm,
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and in about 90 percent of men,
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sperm production after
three to four months will stop.
three to four months will stop.
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Unfortunately, 10 percent of men
don't respond to these hormonal regimens
don't respond to these hormonal regimens
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for reasons that aren't understood.
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For the last several years,
my colleagues and I
my colleagues and I
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have been taking a different approach
to male contraceptive development,
to male contraceptive development,
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one that doesn't involve
the administration of hormones.
the administration of hormones.
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Specifically, we are looking to block
the function of vitamin A in the testes.
the function of vitamin A in the testes.
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Why? Well, for over 90 years
it's been known
it's been known
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that you need vitamin A to make sperm.
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Animals who are deprived
of vitamin A in their diet
of vitamin A in their diet
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stop making sperm
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and restart making sperm again
when the vitamin A is reintroduced.
when the vitamin A is reintroduced.
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The vitamin A that we ingest
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is converted by a family of enzymes
to something called retinoic acid.
to something called retinoic acid.
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One of these enzymes
is found only in the testes.
is found only in the testes.
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It's this enzyme
that we are attempting to block.
that we are attempting to block.
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The blockade of this enzyme
should deprive the testes of retinoic acid
should deprive the testes of retinoic acid
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and stop sperm production
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without affecting vitamin A's functions
elsewhere in the body.
elsewhere in the body.
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We're testing this approach in animals
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and hope to move to human testing soon.
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Obviously, the impact
of such a male contraceptive
of such a male contraceptive
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would go well beyond reproductive biology.
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It's interesting to speculate
about the effect that it would have
about the effect that it would have
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on relationships between men and women.
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One intriguing possibility
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is that a man could monitor
his contraceptive status over time.
his contraceptive status over time.
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In the last several years,
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two groups have introduced
home sperm-testing devices
home sperm-testing devices
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that are iPhone-based
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and that are easy to use.
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A man could test his sperm count
and share the result with his partner.
and share the result with his partner.
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If the man's sperm count were zero,
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the man and his partner
would feel very comfortable
would feel very comfortable
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relying on his contraceptive.
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A tool like this,
coupled with a male contraceptive,
coupled with a male contraceptive,
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could greatly increase the role for men
in preventing unintended pregnancy.
in preventing unintended pregnancy.
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The researchers who are working
on male contraception
on male contraception
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are trying to create
a better future for couples,
a better future for couples,
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a future where contraception is no longer
considered just "a woman's issue,"
considered just "a woman's issue,"
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rather an issue
for couples to decide together.
for couples to decide together.
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So why does the world need a male pill?
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Well, I believe that a male pill
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will help reduce the stubbornly high
rates of unintended pregnancy and abortion
rates of unintended pregnancy and abortion
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and allow men to equally participate
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in contraception.
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Thank you.
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(Applause)
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ABOUT THE SPEAKER
John Amory - Male reproductive health expertJohn Amory is leading research into novel options for male contraception, male infertility and hypergonadism.
Why you should listen
John Amory is is currently examining the potential of using inhibitors of testicular retinoic acid biosynthesis as reversible male contraceptives. He has published more than 130 peer-reviewed papers in the field of male reproduction and serves on the Advisory Board of the Male Contraception Initiative. He is currently Professor of Medicine and Section Head of General Internal Medicine at the University of Washington, where he works as an attending physician on the inpatient medicine wards and in the outpatient General Internal Medicine and Men's Health Clinics.
John Amory | Speaker | TED.com