Infertility: creeping end of human race?

While World Population Day is observed on July 11 every year to deliberate on the challenge of rising birth rates, it eclipses the serious problem of infertility rates, which confronts the human race. India has the dubious distinction of being associated with population explosion but the reality indicates equally strong infertility trends.

The fertility rate of Indians has plummeted by over 50% between 1975 and today, indicates the revised World Population Prospects of 2017. These reports highlight that the fertility rate among Indians is expected to fall below 2.1 in the near future.

A fertility rate of about 2.1 is generally considered the replacement level at which the rate of population growth would remain constant. However, when the fertility rate dips below this figure the population is expected to decline.

The World Health Organisation defines infertility as a failure to achieve a clinical pregnancy after 12 months or more of regular unprotected sexual intercourse. Evolutionary Studies, as a sub discipline of Biology, deals with the history and relationships among individuals or group of organisms to trace their origin and development.

It also examines the functions of organ systems in these organisms and includes an explanation of the complexities of the human reproductive system. These studies have proven humans to have the least reproductive success due to various complexities of their reproductive system. The reproductive success among humans is as low as 20%. This makes humans naturally the least fertile species on the planet.

Human infertility or infecundity is an ongoing, developing trend that has taken shape primarily in the urban world. The global prevalence of childlessness focuses greatly upon the modern world that emphasises on high usage of pesticides, hormone-disruptive chemicals, stressful lifestyle, pollution, improper diet, adulteration, smoking and others that has resulted in either male or female infertility.

A top research scholar on male infertility, Dr Hagai Levine of Hebrew University, Israel, suggests that the rate of falling sperm-count in men in Euro-America, has declined by about 60% over 40 years and has not shown signs of recovery. Other research on female infertility have proven the high occurrence of female infertility due to occupational hazards, hormonal imbalances, cystic fibroids and other causes that affect a woman’s Fallopian tubes.

Newer threats of ‘secondary infertility’ in women, seen in those who have had at least one pregnancy or ‘live’ child birth earlier, are on the rise and lack scientific explanations.

Several studies have proposed authoritative evidence about high rates of infertility among humans.

But, could high infertility rates lead to extinction of any species? Reproductive Biology has evidence of disappearance and extinction in other animal species, too. The wildlife body the International Union for Conservation of Nature has identified the Giant Panda as “vulnerable species” since 2016.

There are a total of 2,164 Giant Pandas in existence, 1,864 of them in wild habitats and 300 captive in zoos and sanctuaries. Apart from the loss of habitat, the prime reason for their limited numbers is linked to their low reproductive rates, according to “Why Pandas Have Trouble Getting Pregnant”,on PBS News hour.

Yet, man still believes that he has the capability to overcome such an existential crisis that may threaten the human race. Thanks to advancements in technology and medicine that provide multiple avenues to ensure procreation in the human race. However, the limitations of medicine have also to be considered.

There are many factors that constrain the adoption and success of in-vitro fertilisation. Also, the high costs of medical treatments for infertility make them very class-oriented and not mass-oriented. That is, these treatments are not accessible to a wide population.

Over 15% of the world population, estimated to about 50 million couples worldwide, today are marred by infertility, estimates a 2015 US-based National Centre for Biotechnology Information(NCBI) report.

The question is, will the human race cease to exist at some point of time if infertility continues to rise and become more common across the world, as it indeed appears to over the years.

Considering the advances in Evolutionary Studies, the continued existence of the human race is feasible only if we conform to the laws of nature, not by going against them. Today, infertility is viewed as one of most prevalent health ailments globally. Intensive research has been instrumental in understanding the vulnerability and complexity of dealing with this specific issue.

While no concrete evidence confirms that the end of the human race due to infertility is nigh, it is necessary to understand the intricacies of nature, along with the possibility that such a threat cannot be completely neglected, given what we know of other species.

(Joseph is Assistant Professor and Iyer a graduate student in the Department of Life Sciences, Christ Deemed to be University, Bengaluru)