How a male contraceptive pill could work | John Amory

Translator: Raúl Fernández Cereijo Reviewer: Serv. de Norm. Lingüística U. de Santiago de Compostela

When I tell people

Cando lle digo á xente

that I'm trying to develop a contraceptive pill for men,

que tento desenvolver unha pílula anticonceptiva para homes,

the response usually varies along gender lines.

as respostas varían dependendo do sexo.

Women say something like,

As mulleres din cousas coma:

"Fantastic. It's about time. When?"

" Que ben! Xa era hora. Para cando?"

(Laughter)

(Risas)

Men have one of two responses.

Os homes só teñen dúas respostas.

They either love the idea,

Ou ben lles soa ben

or they look at me a little warily

ou miran cara a min preocupados

and wonder what exactly I have in store for their testicles.

mentres pensan en que ando a argallar para os seus testículos.

(Laughter)

(Risas)

So why does the world need a male pill?

Entón, por que é necesaria unha pílula masculina?

Well, what if I told you

Que pensades cando vos digo que

that of the six million pregnancies annually in the United States,

dos 6 millóns de embarazos anuais nos EE.UU.

three million of them are unintended?

3 millóns son non desexados?

That's half.

Iso é a metade.

That's a really surprising number.

É un número moi sorprendente.

And those three million unintended pregnancies

E eses 3 millóns non desexados

account for the vast majority of the more than one million abortions

explican os máis dun millón de abortos anuais

annually performed in the United States.

que se levan a cabo nos Estados Unidos.

Happily, the rate of unintended pregnancy has fallen in the last few years

Por sorte, a taxa de embarazos non desexados minguou

by about 10 percent.

nos últimos anos ao redor dun 10 %.

This is because more women are using effective, long-acting,

Isto débese a que máis mulleres usan métodos anticonceptivos

reversible forms of contraception.

efectivos, reversibles e a longo prazo.

But we still have a long way to go.

Pero aínda queda moito por facer.

One approach that's finally becoming a real possibility

Unha estratexia que á fin estase volvendo realidade

is better contraceptive options for men.

é a de mellores opcións anticonceptivas para homes.

Think about it.

Pensádeo.

We have over a dozen methods of contraception for women:

Temos unha ducia de métodos anticonceptivos femininos:

pills, patches, IUDs, shots, sponges, rings, etc.

pílulas, parches, DIU, inxeccións, esponxas, aneis...

For men, we've had the same two options

Para os homes sempre tivemos as dúas mesmas opcións

for more than a hundred years:

durante máis dun século:

condoms and vasectomy.

preservativos e vasectomía.

Despite having only two options,

A pesar de termos só dúas opcións,

both of which have significant drawbacks,

ambas as dúas teñen grandes desvantaxes.

men currently account for 30 percent of all contraceptive use,

Os homes representan o 30 % do uso total de anticonceptivos,

with 10 percent of couples relying on vasectomy

das cales un 10 % das parellas confían na vasectomía

and 20 percent of couples using condoms.

e un 20 % usan o preservativo.

Why are 20 percent of couples relying on condoms for contraception

Por que o 20 % das parellas confían no preservativo

when condoms have a one-year failure rate of over 15 percent?

se estes teñen un índice de erro anual de máis do 15 %?

It's because many women can't either safely take

Débese a que as mulleres ou ben non poden tomar de forma segura

currently available female contraceptives, for reasons such as blood clots,

os anticonceptivos dispoñibles por motivos como coágulos de sangue,

or they can't tolerate the side effects.

ou ben non dan tolerado os efectos secundarios.

So if we think a male contraceptive would be useful, the next question is:

Así que se pensamos que sería útil un anticonceptivo masculino,

o seguinte é preguntarse como poderiamos desenvolvelo.

How do we go about developing one?

Well, there's two general approaches.

Ben, hai dous enfoques xerais.

The first approach is to try and interfere

O primeiro é tentar interferir no xeito en que o esperma

with the way the sperm swim towards or bind to the egg.

nada cara ao óvulo ou se une a el.

This approach turns out to be really difficult,

Este enfoque resulta ser verdadeiramente complicado

because it's hard to get enough medication in the small volume of the ejaculate

porque é difícil concentrar medicación abondo nese pequeno volume de esperma

and have it still work inside the female reproductive tract.

e que siga facendo efecto ao longo do tracto reprodutor feminino.

This is why there's been a lot more work done on the second approach,

Por iso se investigou moito máis na segunda opción,

which is turning off sperm production entirely.

que trata de frear totalmente a produción de esperma.

This is also challenging.

Tamén é unha técnica desafiante.

Why? Turns out that men make a lot of sperm.

Por que? Resulta que os homes producen moito esperma.

(Laughter)

(Risas)

Men make a thousand sperm every second

Un home produce mil espermatozoides por segundo

and to have an effective contraceptive,

e para obter un anticonceptivo eficaz

you need to get that level of sperm production

tense que reducir ese nivel de produción

down to one percent of its normal value.

ao 1 % do seu valor normal.

The good news is, this is possible,

As boas novas son que isto é posible,

almost.

ou case.

The most studied approach has been to use hormones to suppress sperm production.

A técnica máis estudada foi usar hormonas para deter a produción de esperma.

Testosterone and progesterone, when administered together,

A testosterona e a proxesterona, administradas á vez,

will suppress the signals from the brain to the testes to make sperm,

reprimen os sinais do cerebro aos testículos para crearen esperma,

and in about 90 percent of men,

e nun 90 % dos homes,

sperm production after three to four months will stop.

a produción cesa despois de 3-4 meses.

Unfortunately, 10 percent of men don't respond to these hormonal regimens

Por desgraza, o 10 % dos homes non responden a estes tratamentos

for reasons that aren't understood.

por razóns descoñecidas.

For the last several years, my colleagues and I

Nos últimos anos, os meus compañeiros e mais eu

have been taking a different approach to male contraceptive development,

estivemos a desenvolver unha vía distinta para a pílula masculina,

one that doesn't involve the administration of hormones.

unha que non implique hormonas.

Specifically, we are looking to block the function of vitamin A in the testes.

Concretamente, buscamos impedir a función da vitamina A nos testículos.

Why? Well, for over 90 years it's been known

Por que? Ben, sábese dende hai máis de 90 anos

that you need vitamin A to make sperm.

que a vitamina A é necesaria para producir esperma.

Animals who are deprived of vitamin A in their diet

Os animais privados de vitamina A na súa dieta

deixan de producir esperma

stop making sperm

and restart making sperm again when the vitamin A is reintroduced.

e comezan a producilo cando a vitamina A se reintroduce de novo.

The vitamin A that we ingest

A vitamina A que nós consumimos

is converted by a family of enzymes to something called retinoic acid.

é transformada en ácido retinoico por unha familia de enzimas.

One of these enzymes is found only in the testes.

Un destes enzimas atópase só nos testículos.

It's this enzyme that we are attempting to block.

Nós tentamos bloquear este enzima.

The blockade of this enzyme should deprive the testes of retinoic acid

Ao bloquear este enzima, deberíase privar aos testículos de ácido retinoico

and stop sperm production

e paralizar a produción de esperma

without affecting vitamin A's functions elsewhere in the body.

sen afectar as funcións da vitamina A no resto do corpo.

We're testing this approach in animals

Estamos probando esta técnica con animais

and hope to move to human testing soon.

e esperamos iniciar as probas en humanos moi axiña.

Obviously, the impact of such a male contraceptive

Por suposto, o impacto deste anticonceptivo masculino

would go well beyond reproductive biology.

vai máis aló da bioloxía reprodutiva.

It's interesting to speculate about the effect that it would have

É interesante especular sobre os efectos que tería

on relationships between men and women.

nas relacións entre homes e mulleres.

One intriguing possibility

Unha posibilidade interesante

is that a man could monitor his contraceptive status over time.

é que os homes poderían monitorizar o seu estado contraceptivo en calquera momento.

In the last several years,

Nos últimos anos,

two groups have introduced home sperm-testing devices

dous grupos presentaron aparellos de análise de esperma

that are iPhone-based

que funcionan co teléfono móbil

and that are easy to use.

e son sinxelos de usar.

A man could test his sperm count and share the result with his partner.

Poderíase facer un reconto de espermatozoides

e compartir o resultado coa parella.

If the man's sperm count were zero,

Se o reconto fose cero, sentiríanse cómodos ao confiar no método.

the man and his partner would feel very comfortable

relying on his contraceptive.

A tool like this, coupled with a male contraceptive,

Unha ferramenta coma esta, xunto co contraceptivo masculino,

could greatly increase the role for men in preventing unintended pregnancy.

podería axudar o papel do home na prevención de embarazos non desexados.

The researchers who are working on male contraception

Os investigadores que traballan nisto

are trying to create a better future for couples,

intentan facer un futuro mellor para as parellas,

a future where contraception is no longer considered just "a woman's issue,"

un futuro onde a anticoncepción non sexa considerada só "cousa de mulleres",

senón unha cousa que as parellas deben decidir xuntas.

rather an issue for couples to decide together.

So why does the world need a male pill?

Entón, por que o mundo precisa unha pílula masculina?

Well, I believe that a male pill

Ben, eu penso que a pílula masculina

will help reduce the stubbornly high rates of unintended pregnancy and abortion

axudaría a reducir as enormes taxas de embarazos non desexados e de abortos,

and allow men to equally participate

e permitiríalles aos homes participar en igualdade de condicións

in contraception.

na anticoncepción.

Thank you.

Grazas.

(Applause)

(Aplausos)