Anencephaly: A devastating abnormality

Anencephaly, a severe congenital (birth) defect, occurs in about 1 in 3,000 pregnancies. Above the eyebrows and ears, there is no hair, scalp or brain. Only the brainstem, which controls heart rate and breathing, remains.

The afflicted fetuses survive only briefly after birth, usually a few minutes or hours – less often days. During residency in a Scottish university obstetrical hospital, I encountered two cases of anencephaly, both in first-trimester pregnancies – aborting – one spontaneous, the other induced. Ultrasound, in early use then, readily visualized this severe abnormality.

It is not entirely understood why, but prenatal care has definite benefits. The basic, routine exams are simple and brief: pulse, blood pressure (for hypertension), urine for protein (kidney problems, toxemia), sugar (gestational diabetes) and weight. Especially in the last trimester, the abdomen and uterus are examined, although nowadays, an ultrasound will likely have been done.

In a rural general practice, before ultrasounds were on every street corner, I examined a young woman, her first pregnancy, near term – due date a few days away. The hands-on examination is useful in determining fetal presentation, breech (butt toward the pelvis), or vertex, the most common (head to pelvis). The patient’s record had suggested vertex. My little problem that day was that I could not determine any presentation; I wasn’t sure that I actually felt a head. Off she went, 70 miles for an ultrasound and a diagnosis of an anencephalic, term fetus. I made several exploratory phone calls to organ transplant centers.

The family was devastated. From late afternoon, my phone rang hourly, taking calls from the wife, husband and their parents too. I promised to meet them early the next morning. I called the OB nurses and explained the situation – we would induce labor. However, fetal organ transplantation was not technically advanced; organ donation was not an option. Labor and delivery went quickly, smoothly and somberly – the baby breathed only minutes.

Now that organ transplantation has progressed significantly, many organs from anencephalics go unused. One problem is the definition of “dead donor.” Normally, brain death allows termination of life support and organ donation may proceed. In anencephaly, there is a catch-22: If there is no brain, there is no brain death. Experience has demonstrated that anencephalics, kept on life support, the heart functioning, awaiting “somatic death,” suffer organ deterioration rendering donation futile. Medical ethicists have suggested amending the “dead donor” rules and the law. The debate was huge, but the problem has essentially gone away.

Medical science has demonstrated the value of folate (or folic acid), a simple vitamin, which is now, by U.S. Food and Drug Administration mandate, added to flour and grains. Also supplemented before conception and during the first trimester, folate has significantly reduced the incidence of anencephaly and also spina bifida. And, some anencephalic fetuses, detected early by ultrasound, are aborted. Genetics may be a factor in anencephaly and there is a strong suggestion that maternal hyperthermia, fever, saunas and hot tubs should be avoided – it’s difficult science.

My patient called me about a year after her tragic pregnancy. She was effusive, grateful and newly pregnant with a normal fetus. Dr. Fraser Houston is a retired emergency room physician who worked at area hospitals after moving to Southwest Colorado from New Hampshire in 1990.