Anencephaly is a congenital fetal defect involving the absence of the higher brain, sometimes with the absence of the brain stem, but usually with the brain stem intact. While it is possible to diagnose anencephaly as early as the 10th or 12th week of pregnancy, in clinical practice it is typically diagnosed between 15-18 weeks. Statistics suggest that over 95% of anencephalic neonates will not survive more than a week after birth. Although a few cases have been reported in which anencephalic infants have survived for three or four months, these cases are rare and call the diagnosis itself into question. Regardless, any prolonged survival of the anencephalic infant would require continuous aggressive medical treatment that may be considered disproportionate means. [The Medical Task Force on Anencephaly, "The Infant with Anencephaly," New England Journal of Medicine 332,10 (1990): 669-74].
In the 1950s and 1960s, before the use of ultrasound techniques for monitoring fetal development, the prevalence rates for anencephaly ranged from 1.39 to 1.93 per 1,000 births [D. Alan Shewmon, "Anencephaly: Selected Medical Aspects," Hastings Center Report 18,5 (1988): 11-19]. At present, the prevalence rate is believed to be about .3 per 1,000 live births. However, this rate does not include fetuses from pregnancies that are terminated or still-born. One recent study tracked the occurrence of anencephaly both at birth and up to 20 weeks gestational age over a 15-year time period. At birth, the prevalence rate was .24 per 1,000 births. Up to 20 weeks, the prevalence rate was .79 per 1,000 pregnancies. Over the 15-year period, these rates remained constant [T.J. Owen, J.L. Halliday, C.A. Stone, "Neural Tube Defects in Victoria, Australia: Potential Contributing Factors and Public Health Implications," Australian & New Zealand Journal of Public Health 14,6 (2000): 584-9 (though this study was performed in Australia, it is consistent with previous, smaller studies performed in various locations around the U.S.)]. One possible reason for the decreased prevalence over the last 4 to 5 decades is improved prenatal nutrition, particularly, an increase in the intake of folic acid, which studies suggest reduces the incidence of neural tube defects in general by 19-50 percent [M.A. Honein, L.J. Paulozzi, T.J. Mathews, et. al., "Impact of Folic Acid fortification of the U.S. Food Supply on the Occurrence of Neural Tube Defects," Journal of the American Medical Association 285, 23 (2001):2981-6; C.E. Butterworth, Jr., A. Bendich, "Folic Acid and the Prevention of Birth Defects," Annual Review of Nutrition 16 (1996): 73-97]. There is, however, no cure for anencephaly, and many physicians recommend aborting the fetus in order to reduce the risk of potential complications that might result from continuing the pregnancy, and in an attempt to alleviate anxiety on the part of the mother and family.
Because the anencephalic fetus is a live human being but does not have a significant chance of surviving for an extended period of time after birth and will never be able to exercise the spiritual and moral capacities of human life, e.g., love of God and neighbor, there has been some disagreement as to the moral status of inducing labor and delivery of an anencephalic fetus within the Catholic moral tradition. For example, some moralists have argued that because the higher brain is absent the anencephalic is not a person, and therefore has no moral claim to the right to life. The Catholic Church, however, teaches that human dignity—not personhood—is the basis for the right to life. Others have argued that labor and delivery may be induced for several reasons: 1) in order to avoid potential pathologies affecting the mother that might accompany a full term delivery; 2) because the continuation of pregnancy is futile with respect to its inherent goal of developing a human being that is capable of performing human acts; and, 3) as a means of avoiding spiritual and psychological harm to the mother and father. To the contrary, others argue that inducing labor and delivery for any of these reasons would not be morally justifiable because the object of the act in each case would be the direct killing of innocent human life (i.e., it would be a direct abortion), which is never permissible according to Catholic moral teaching. [For a review of all of these arguments, see Fr. Kevin D. O'Rourke, "Ethical Opinions in Regard to the Question of Early Delivery of Anencephalic Infants," Linacre Quarterly 63,3 (1996): 55-59.]
In an attempt to settle these debates, the U.S. Catholic Bishops published a statement entitled, "Moral Principles Concerning Infants with Anencephaly" [Origins 26,17 (1996): 276, 1996]. In this document, the bishops stated that " . . . the rights of a mother and her unborn child deserve equal protection because they are based on the dignity of the human person whatever the condition of that person. Consequently, it can never be morally justified directly to cause the death of an innocent person no matter the age or condition of that person." As applied to the case of anencephaly, the Bishops' statement precludes the directly intended termination of the pregnancy as a means of treating or protecting the mother. This statement does not, however, preclude the indirect termination of the pregnancy, if the death of the fetus is a foreseen but unintended consequence of an operation, treatment, or procedure that is intended to cure a proportionately serious pathological condition of the mother [see, the Ethical & Religious Directives for Catholic Healthcare Services, #47]. Since an anencephalic fetus would normally not in and of itself constitute a pathological condition of the mother, this application of the principle of double effect would only apply when there are additional complications of the pregnancy that pose a proportionately serious threat to the health and life of the mother. As the bishops further state:
"Nor is such termination permitted after 'viability if early delivery endangers the child's life due to complication of prematurity [emphasis added]. In such cases it cannot reasonably be maintained that such a termination is simply a side effect of the treatment of a pathology of the mother (as described in Directive 47). Anencephaly is not a pathology of the mother, but of the child, and terminating her pregnancy cannot be a treatment for a pathology she does not have. Only if the complications of the pregnancy result in a life-threatening pathology of the mother, may the treatment of this pathology be permitted even at a risk to the child, and then only if the child's death is not a means to treating the mother."
The question remains, however, as to whether inducing labor and delivery after the normal point of viability and at a point that the fetus's life would not be placed "at risk due to complications of prematurity" (e.g., 33 weeks gestational age) could ever be justified. At this point, one might argue that labor and delivery could be induced before full term for a proportionately serious reason, e.g., the psychological well-being of the mother [Norman Ford, "Early Delivery of a Fetus with Anencephaly," Ethics & Medics 28, 7 (July 2003): 3-4]. Some theologians, however, do not believe that the concept of viability applies in the case of anencephaly, because the infant is essentially "born dying." Moreover, they argue that there is no sound basis for the claim that early induction actually relieves the psychological and emotional distress of the mother [Eugene Diamond, "Anencephaly and Early Delivery," Ethics & Medics 28, 10 (October 2003): 2-3]. According to this line of thought, the only suitable moral opinion in light of the bishops' statement is that the pregnancy should be allowed to go full term, unless there are complications of the pregnancy that present a direct threat to the mother's health.