Birth Control for Men: Coming Soon?

Safe, convenient, reversible contraception allows women and men worldwide to plan their families and ensure that they are ready to nurture and provide for the children they parent. So why are so few male contraceptive methods available?

Safe,
convenient, reversible contraception allows women and men worldwide
to plan their families and ensure that they are ready to nurture and
provide for the children they parent. So why are so few male contraceptive
methods available?

In
America, 62
million women
are
of childbearing age; worldwide, the number is around 1.5 billion.  In the US, when these women
get pregnant, half of their pregnancies will be unplanned
and 42% of these end in abortion. Approximately 40% percent of pregnancies worldwide are
unintended.  Globally, about half of all abortions are considered unsafe
and more than 75% occur in developing countries. 
In order to reduce the number of unsafe abortions worldwide, and to
equip individuals with tools they need to take control of their reproductive
lives, we need to ensure the availability of reversible, effective birth
control solutions with minor side effects for both men and women. 

While
only two male contraceptive options (vasectomy and condoms) are available,
they are both widely used, making it clear that men are willing to accept
responsibility for birth control.  In fact, one study assessed
the responsiveness of men from four continents and nine countries to
the possibility of "male fertility control," and found that on average
more than half of those surveyed were willing to
use such a method.  The legal responsibility associated with fathering
a child is also motivating men to take control of their reproductive
fate.   

Around two-thirds of women in their reproductive years
are sexually active with no intent of getting pregnant, and a typical
woman in America uses contraceptives for around three decades of her life to avoid pregnancy. 
And yet the most popular forms of contraceptives – female hormonal birth
control and the condom barrier method – are not failsafe. One study
found that "traditional" usage of these two methods resulted in
an 8%
and 15%
failure
rate, respectively.  In another study where pill usage was monitored
by both an electronic device and the woman herself, inconsistencies
between the two records highlighted the unreliability of daily birth
control usage.   The women reported proper pill usage 53-59% of the time, while the device reported
an accurate value of 19-33%.  A birth control method that
relies on the user to either administer daily dosages or use at the
time of need is not foolproof.  

Additionally,
current female hormonal contraceptive methods act systemically, and
carry with them many
side effects
, including
nausea, headaches, weight gain, depression, loss of libido, as well
as menstrual problems.  "New" birth control methods often simply
mean a lowered
or altered dosage

of estrogen and progestins, respectively, or a method, like the NuvaRing,
that does not require oral and daily administration.  Given that
the female birth control pill was introduced nearly 50 years ago, it
is an embarrassment to the scientific community that there remain so
few alternatives to hormone-based therapies.

In
a society which strives for equal opportunities for both men and women,
responsibility for birth control should not fall solely on women, nor
should we be content with birth control options currently available
to women.  The idea of a male contraceptive method has been discussed
for decades, and articles appearing in mainstream media frequently promise
a male birth control pill in pharmacies in the near future.  Unfortunately,
a lack of funding and interest from pharmaceutical companies has delayed
progress in this field.  Most private industries are no longer
interested in funding male contraceptive research, for multiple reasons,
including a complicated
FDA approval
process
due to lack
of previous experience

with male birth control, reduced
insurance coverage

of contraceptives in general, and a high
development cost

for a product that would be ideally of low
purchase cost
,
especially in developing countries.  This leaves the public sector
as the sole source of funding, which comes with it both budget and experimental
constraints.  But despite this shortage of financial support, many
innovative scientists around the world are working to make male contraception
a reality. 

In
order to develop a male contraceptive, we must first understand what
is needed for proper male fertility, so that we can suppress or block
that function.  While 50% of infertility in couples is male factor,
a recent study of infertile men attributed infertility to low sperm motility and low
sperm count

Identification of a molecule that is required for male fertility can
facilitate contraceptive development, but may also help in treating
individuals struggling with infertility.

Successful
fertilization is a complicated, evolutionarily fine-tuned event, which,
on a basic level, requires the fusion of a sperm and egg.  Female
hormonal contraceptive methods block egg production.  There are
three biological mechanisms to impede male fertility:

  • Arresting sperm
    production
  • Blocking sperm from
    entering the female reproductive tract
  • Interfering in sperm-egg
    binding

 

In
this article series I will explain the scientific technologies behind
the current global male contraceptive research efforts, describing what
is in the pipeline in terms of both hormonal and non-hormonal contraceptive
approaches.  I will divide these technologies in three categories
based upon the mechanisms described above.  New approaches should
offer clear advantages over existing methods, for example, hormonal
methods that deliver progesterone and testosterone to block sperm production
in men.  Non-hormonal methods offer the benefit of a targeted and
therefore effective approach, including those methods that block sperm
from passing through the vas deferens, as well as heat and ultrasound
approaches that arrest sperm production. 

Ideally, a male contraceptive
would be effective, reversible, with few side effects.  When it
is, not only will we have secured a victory for equality of the sexes,
we will offer couples worldwide a new method for ensuring that they
are able to choose parenthood when they are ready. 

Stay tuned for more articles from Soumya Vemuganti about latest research on contraceptive methods for men.