The world's population is growing at an unsustainable rate. From a baseline figure
of one billion in 1800, global population is predicted to exceed nine billion by 2050
and 87.8% of this growth will be localized in less developed countries. Such uneven
population growth will yield a harvest of poverty, malnutrition, disease and environmental
degradation that will affect us all. Amongst the complex mixture of
political, social, cultural and technological changes needed to address this issue, the
development of improved methods of fertility regulation will be critical. The
inadequacy of current contraceptive technologies is indicated by recent data suggesting
that the contraceptive needs of over 120 million couples go unmet every
year. As a direct consequence of this deficit 38% of pregnancies are unplanned and
more than 50% end in an abortion, generating a total of 46 million abortions per
annum particularly among teenagers. If safe, effective contraceptives were available
to every couple experiencing an unmet family planning need, 1.5 million lives
would be saved each year (UNFPA 2003).
Progress in contraceptive technology should not only generate more effective
methods of regulating fertility, but should also provide a range of methods to meet
the changing needs of the world's population. Contraceptive practice was revolutionized
in 1960 in the US and 1961 in Europe by the introduction of the oral
contraceptive pill by Gregory Pincus, MC Chang and colleagues, based on fundamental
hormone research conducted in Germany. While the pill continues to
represent a highly acceptable and effective method of fertility regulation, we should
not lose sight of the fact that this approach has its roots in the endocrinology of the
1920s and was designed to meet the clinical and social needs of the 1960s. During
the past 50 years we have seen no radically new forms of family planning designed
to meet the contraceptive needs of the twenty-first century. For example, fertility
control in the future will have to be linked with the need to prevent the spread of
sexually transmitted diseases (STD). Every year at least 340 million new cases of
curable STD are notified, one third in young people under 25 years of age (World
Health Organization 2001). Recent figures on AIDS indicate that this condition
is continuing to spread at a rate of 2.7 million new cases a year, generating an
v
estimated annual death toll of 2 million (UNAIDS and World Health Organization
(2009). Africa has been decimated by the disease and it is now rapidly gaining hold
in SE Asia. Chlamydia is also spreading rapidly and is now one of the most
commonly diagnosed bacterial sexually transmissible infections (Hocking et al.
2008). The spread of STDs is particularly marked in young women aged 15 25, for
whom the risk of infection is approximately six times greater than their male
counterparts. For these women, development of dual-purpose methods that simultaneously
target pregnancy and STDs are desperately needed. Similarly, the contraceptive
strategies we develop for the future should also recognize the increasing
desire of men to actively participate in the family planning process. Furthermore, it
should be emphasized that whereas in the past approximately 10 years of contraceptive
protection was required in a lifetime, nowadays the average couple will
require 30 years of contraception to meet their family planning needs, due to earlier
onset of sexual activity, later time point for first birth and greater intervals between
births. As a consequence we not only have to deal with the differing contraceptive
needs demanded by diverse cultural and social environments, but also with the
changing needs of individual women over their reproductive lifespan.
Given all the major improvements in healthcare that have been delivered by
molecular medicine in the last half-century, it is remarkable that something that
touches all of our lives should be so neglected. The major reasons for this state of
affairs have been three fold. First, the specification for new contraceptive methods
is extremely difficult to achieve. We want the new generation of contraceptive
agents to combine absolute efficacy with the complete absence of adverse side
effects. Because contraceptives are the only medicinal compounds that we give to
perfectly healthy people, the risk-benefit equation is strongly driven the right i.e.,
all benefit, no risk. Developing pharmaceutical agents that meet such exacting
standards will be hard. Secondly, the history of contraceptive development has
been beset with the frustration of trying to project radically new methods of fertility
control from an extremely narrow science base. It is extremely difficult to interfere
with the reproductive system in a controlled, targeted manner, if we do not
understand how the system works. Since the pharmaceutical industry is not primarily
designed to make fundamental contributions to the science-base, this role has
been left to public sector research institutions and, as a result, progress has been
painfully slow. This situation has been exacerbated by the third factor, which is the
low priority given to basic reproductive research by public sector funding agencies.
Infertility is not seen as a life-threatening condition in the same way as cancer,
multiple sclerosis or kidney failure, and governmental research priorities tend to
reflect this perception, no matter how short-sighted.
Hopefully contraception will not remain a neglected field for much longer. The
political climate has recently changed to one that is more sympathetic to reproductive
research. In the past decade we have also witnessed the birth of private public
partnerships in order to improve our fundamental understanding of the reproductive
process through the creation of coordinated international networks. For example
in 1997, the Rockefeller Foundation and Ernst Schering Research Foundation
developed one of the first such networks to intensify research on the posttesticular
vi Preface
maturation of spermatozoa, utilizing new approaches in molecular pharmacology
the application of molecular pharmacology for posttesticular activity (AMPPA)
network . Hopefully this will be the predecessor of further targeted networks in the
future. With the advent of such initiatives, as well as parallel developments in the
fields of pharmacology and drug design, the scene is now set for dramatic improvements
in the technologies we shall use to regulate our future fertility.
This volume could not have been produced at a more opportune moment. It
brings together contributions from all corners of the globe on all aspects of
reproductive biology pertinent to contraceptive development. It contains cutting
edge assessments of the molecular mechanisms regulating male and female reproduction
and the new opportunities for contraceptive development to emerge as a
consequence of this knowledge. It also contains expert evaluations of the potential
for product development in the contraceptive field. This book looks forward to a
future where men and women will be able to choose from a range of novel, safe,
effective, contraceptive methods tailored to their individual needs. Hopefully it will
inspire a new generation of young scientists and clinicians to exploit recent gains in
our understanding of reproductive mechanisms, to engineer such new approaches to
the regulation of human fertility