This case study explores the recent (2010 - 2016) outbreak of neural tube defects, specifically anencephaly, in a rural three-county region of Washington state, particularly Yakima, WA. The case study focuses on the biological aspects of teratogens that may cause birth defects as well as epidemiological investigations of disease outbreaks. By the end of the case, students will have explored how our environment may have severe biological consequences on the human body during pregnancy and will have evaluated governmental and scientific investigations of a rare outbreak of birth defects. This clicker case study was developed for a non-majors biology course entitled "Human Development: Conception to Birth," although it could be taught in any introductory biology course for majors or non-majors during a unit on human reproductive biology or developmental biology. The case assumes that students have no prior knowledge of developmental biology or birth defects. The case study could also be adapted for upper-division courses by getting more in-depth on the specifics of teratogen mechanisms, the developmental biology and physiology of neural tube defects, or more complex epidemiological analyses.
Because anencephaly is a lethal condition, heroic measures to extend the life of the infant are contraindicated. The physician and medical care team should focus on providing a supportive environment in which the family can come to terms with the diagnosis and make preparations for their loss.
Families who are not aware of the diagnosis of anencephaly prior to birth or for whom the diagnosis is still fresh probably will need extra emotional support and possibly grief counseling. Families who have had some time to adjust to the diagnosis prior to delivery and who have had an opportunity to begin the grieving process ahead of time may seem well prepared, but they also will need adequate time to grieve and come to closure. The presence of family, friends, or clergy may be helpful in many cases.
Families often want to hold the baby after delivery, even if the baby is stillborn, and families wanting photographs of the baby with the family are not unusual. A cap or head covering of some sort is useful to minimize the visual impact of the malformation. Some families want to see the lesion, and this may help to dispel mental pictures, which are often worse than the actual malformations. In most cases, direct personal contact with the baby may help the parents to actualize the medical information they have been given and may help in the process of grief resolution.
If parents have chosen a name for the baby, they may be comforted if the doctor refers to the baby by name.
Feelings of guilt are normal responses of parents of a baby with serious birth defects. The involvement of genetic counselors, if available, may be particularly useful to parents in this situation because of their experience in dealing with a wide range of birth defects.
With timely prenatal diagnosis of this lethal disorder, the option of pregnancy termination should be presented to the couple. For couples who elect to continue the pregnancy, the possibilities of preterm labor, polyhydramnios, failure to progress, and delayed onset of labor beyond term also should be discussed.
Families commonly inquire about organ donation after the diagnosis of anencephaly. This cannot practically be arranged without crossing the lines of ethical care. Patients should be affirmed in their desires to see something meaningful come from the tragedy of having a pregnancy affected with anencephaly.
All patients diagnosed prenatally with a fetus affected by anencephaly should be offered a consultation with a care provider who is skilled in delivering grave information and is knowledgeable about recurrence risk, prevention, screening, and diagnostic testing options for future pregnancies.
Although a geneticist or genetics counselor is an ideal source and may be best suited for exploring family history, an experienced maternal fetal medicine physician or properly trained obstetrician may provide requisite information, especially in regions of the United States where there are inadequate numbers of geneticists or genetic counselors. Specific information related to the management of an ongoing pregnancy should be discussed during this consultation.
Once a diagnosis of anencephaly is made, pregnancy management varies according to the gestational age at diagnosis. At pre-viable gestational ages, the option of pregnancy termination should be among those discussed. The gestational age limits for this procedure are state specific and subject to the training and skill of the physician available to perform the pregnancy termination.
When patients choose not to proceed with pregnancy termination or when the pregnancy has progressed to a viable gestational age such that pregnancy termination is no longer an option (except in rare locations throughout the United States), attention should be focused on whether the labor will be induced or spontaneous and, if the former, at what gestational age.
Due to the physical stresses of pregnancy compounded by the emotional stress of carrying a fetus with a lethal birth defect, or because of the identification of medical conditions (eg, preeclampsia) that may complicate any pregnancy, labor induction may be considered.
Focused discussions directed at neonatal resuscitation efforts should be held in advance of labor. These discussions should include a discussion of neonatal procedures used to resuscitate neonates, the cost of these measures, and alternatives to aggressive resuscitation. It is often best to include a neonatologist in these discussions. Clear documentation of these discussions is warranted. When delivery is planned in a hospital setting, labor and delivery nurses, obstetric care providers, and pediatric/neonatal attendants should be informed of the patient’s wishes for her child.
Because of the lethal nature of this condition, tocolysis (medical management to reduce uterine contractions) in an effort to prevent preterm birth is not a reasonable option, nor is cesarean delivery.
The pregnancy management of a child with lethal and nonlethal birth defects can be complicated by available resources. In addition to having a wealth of experience in dealing with grieving patients, some delivering hospitals are vastly more experienced in the management of pregnancies complicated by known lethal fetal birth defects. For this reason we recommend that babies with anencephaly be delivered at such centers, when possible.
Every couple with a child who has anencephaly should consult with a geneticist and/or a genetic counselor to obtain information regarding recurrence risks, prevention, screening, and diagnostic testing options for future pregnancies and to assess the family history. Ideally, a genetic counselor should be consulted prenatally and should remain involved, as needed, until the family comes to closure after the conclusion of the pregnancy. Genetic counselors are trained and are generally skillful in helping a family work through the complex psychosocial issues that are commonly encountered in a new diagnosis of anencephaly.
Folic acid supplementation and/or a folate-enriched diet prior to and during future pregnancies are recommended. Obtaining enough folates from diet alone to effectively prevent recurrences in future pregnancies is extremely difficult. The U.S. Public Health Service recommends that women capable of becoming pregnant consume 400 µg of folic acid daily for NTD prevention.