PEDIATRICS Vol. 107 No. 6 June 2001, pp. 1421-1422

COMMENTARY:
Unnatural Selection

The more masterful the genetic sciences have become, the more they have corroded the authority of moral custom in medical and reproductive behavior.¹

The recent completion of the Human Genome Project has prompted some bioethicists² to examine the complex moral issues that lie ahead with the arrival of genetic engineering on the scene in everyday medicine. Given the abysmal horrors conducted in the name of "eugenics" in the last century, they point out, "it has become commonplace to argue that eugenic goals will play no part in how new genetic knowledge is used." Nonetheless, they opine, "it is important to distinguish between genetic changes undertaken with respect to improving a group or population and genetic change that takes a single individual as its focus."

It is morally offensive when governments or any other agents compel or coerce reproductive behavior, the bioethicists assert: "The right to reproduce without interference from third parties is one of the fundamental freedoms recognized by international law and moral theories from a host of ethical traditions." However, they argue, parents have the right to avoid hereditary disease (Tay-Sachs disease and sickle cell anemia are given as examples) and, "if their choice is free and informed, then there is no reason to think that such a choice is immoral on grounds of force or coercion."

I find it interesting that these concerns about explicit genetic engineering in our species are now coming into focus. In fact, a blunt and less obvious form of engineering to "fix" human reproduction³ has been going on for more than a century. The initial efforts to perfect human reproduction on a large scale, by rescuing marginally viable neonates, were fueled by social considerations. (Patriotic French obstetricians began concerted efforts to rescue newly-born "weaklings" in the 1870s because of fears about depopulation brought on by immense loss of life in the Franco-Prussian War of 1870-1871, and by a falling birth rate.^4,5) But the long-term biological consequences of this unique human experiment have never been examined. The venture resembles eugenics stood on its head: It might be called "unnatural selection."

The early success in keeping marginally viable infants alive has led, in recent years, to increasingly energetic methods to reduce neonatal mortality without limit. The modern programs of neonatal intensive care have been evaluated in terms of the overall health and well-being of survivors. But we have not examined the population-wide consequences of this progressively more compulsive form of selection: Marginally viable, fetal-infants are now kept alive in numbers never before experienced in the history of our species.

For example, the assisted-reproduction technologies have increased unnatural selection; and the full effects of these artificial modes of procreation on gene frequencies in future human populations are, again, unknown. A Canadian survey of in vitro fertilization within the province of Alberta from 1994 through 1996, revealed that this technology was associated with a striking increase in the rate of low birth weight outcome (especially the rate of infants weighing <1.5 kg), and in the rate of multiple births in the province.⁶ The frequency of multiple gestation, and the coincident prevalence of prematurity, are especially high after treatment of infertility by ovarian stimulation with gonadotropins. In 1 survey of 3347 consecutive hormone-treatment cycles in 1494 infertile women, 441 pregnancies occurred: 314 resulted from the conception of singletons; 88, twins; 22, triplets; 10, quadruplets; 5, quintuplets; and 2, sextuplets.⁷

The unfolding of the full life history of the population cohort of marginally viable "micropreemies," whose survival has been made possible in unprecedented numbers by treatment with surfactant and by complex life-prolonging machinery, needs to be watched closely. For example, Barker's disputed, but nonetheless fascinating, hypothesis (about the fetal/infant-origins of coronary heart disease and other adult chronic diseases^8,9) will face its severest test several decades from now, when these very small ex-premature infants reach middle age. And the exposure of present-day neonates to numerous potent drugs like dexamethasone¹⁰ greatly extends the time required for surveillance. Recently, a large follow-up study reported the fate all the infants born at 25 or fewer weeks of gestation in the United Kingdom and Ireland over a 10-month period in 1995811 were admitted to intensive care units, 314 were sent home alive, and 283 were examined at a median age of 30 months.¹¹ We may have to wait until the offspring of this cohort are examined (as in the diethylstilbestrol disaster¹²) before we can make an informed judgment about neonatal medicine's total biological impact.

Rescuers in the neonatal care industry are making impressive efforts to increase the efficiency of human production. But what is the price of this extraordinary uncoupling of our species from millions of years of natural selection? Those who remember the disconnect between knowledge and value in the eugenics debacle³ have an uncontrollable urge to cry out (as Cromwell did in 1650): "I beseech you, in the bowels of Christ, think it possible you may be mistaken."

ACKNOWLEDGMENT

I am grateful for the suggestions of Sir Iain Chalmers, who reviewed a draft of these comments.

William A. Silverman, MD
Greenbrae, California 94904-1947

FOOTNOTES

Received for publication Dec 27, 2000; accepted Dec 27, 2000.

Address correspondence to William A. Silverman, MD, 501 Via Casitas, Apartment 421, Greenbrae, CA 94904-1947. E-mail: fumer2{at}juno.com

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