PUBH 3100 Week 11 Final Condition Report Example

A Defect That Forms Before Most Pregnancies Are Known: A Final Condition Report on Neural Tube Defects, Their Mechanism and Course, and a Defense of Mandatory Folic Acid Fortification Against Its Two Most Common Objections

Student Name

Walden University

PUBH 3100: Human Disease and Prevention

Instructor Name

Month Day, Year

A Defect That Forms Before Most Pregnancies Are Known: A Final Condition Report on Neural Tube Defects, Their Mechanism and Course, and a Defense of Mandatory Folic Acid Fortification Against Its Two Most Common Objections

Purpose

This report has two parts. The first describes neural tube defects, a set of grave malformations of the developing brain and spinal cord: what they are, how they arise and what happens to affected pregnancies and children. The second defends one population-level action, mandatory fortification of grain products with folic acid, against the two objections most often raised against it. The description supplies the reason for the defense: the defect forms so early in pregnancy that measures aimed at individual pregnant women arrive too late for many.

Part One: The Condition

What Neural Tube Defects Are

The neural tube is the structure in an embryo that becomes the brain and spinal cord. It forms as a flat plate of tissue that folds and closes into a tube during the first month after conception, usually by about 28 days. When part of the tube fails to close, the result is a neural tube defect. Failure at the head end causes anencephaly, in which much of the brain and skull do not develop. Failure lower down causes spina bifida, in which part of the spinal cord and its coverings are exposed or protrude through an opening in the spine.

The Mechanism as Understood

Closure of the neural tube requires rapid cell division and DNA synthesis, which depend on folate, a B vitamin. Low folate status around conception is associated with a higher risk of defects, and genetic differences in how the body handles folate add to risk. The full mechanism is not known; other factors, including some medications and maternal diabetes, also raise risk. The firmest evidence that folate matters comes from a randomized trial: among women who had previously had an affected pregnancy, folic acid supplements taken before conception and in early pregnancy reduced the risk of a recurrence by about 72% (MRC Vitamin Study Research Group, 1991).

The Course

Anencephaly is fatal before or shortly after birth. Spina bifida varies in severity. Many children survive with surgery but live with lifelong effects that can include leg weakness or paralysis, bladder and bowel problems and fluid buildup in the brain requiring a shunt. Many affected pregnancies end in miscarriage or termination, which means counts of affected live births understate how often defects occur. Surveillance systems that rely on birth certificates alone miss a large share of cases, a limitation that also affects the fortification evidence discussed below.

Why Timing Matters

Because closure is complete by about four weeks after conception, roughly two weeks after a first missed period, a woman may not yet know she is pregnant when the critical period ends. Nearly half of U.S. pregnancies, 45% in 2011, were unintended (Finer & Zolna, 2016), so advice to start supplements after a positive pregnancy test comes too late for many. That fact is the starting point for a population approach.

Part Two: The Action and Its Defense

The Action

Since 1998, the United States has required that enriched cereal grain products, such as flour, bread and pasta, include folic acid. The measure reaches women of childbearing age whether or not they plan a pregnancy or take supplements. Once fortification began, neural tube defects noted on birth certificates dropped by 19%, from 37.8 per 100,000 live births before fortification to 30.5 after it (Honein et al., 2001). Because this was a before-and-after comparison, other changes could contribute, and birth certificates miss many affected pregnancies, but the decline began with pregnancies conceived after fortification took effect.

Objection One: Fortification Could Mask Vitamin B12 Deficiency

The concern is that high folic acid intake can correct the anemia caused by vitamin B12 deficiency while the nerve damage from that deficiency continues, delaying diagnosis, particularly in older adults. A study of patients with low vitamin B12 levels found that the proportion without anemia did not increase from before fortification, 39.2%, to after it, 37.6%, including among patients over 60 (Mills et al., 2003). The concern was reasonable before fortification began, because folic acid at high doses can correct the blood changes of B12 deficiency; the evidence since then has not shown the masking effect at the levels added to food.

Objection Two: Individual Supplements Are Enough

The second objection is that women can take folic acid supplements and that adding it to everyone's food is unnecessary. The timing of neural tube closure answers this objection. Supplements protect women who take them before conception, but many pregnancies are not planned, and daily pill-taking is easy to miss. Fortification reaches women who would not otherwise be protected during the weeks that matter. Fortification also does not depend on remembering a daily pill, which matters for a protection needed at a time many women do not know they need it. Supplements and fortification are complements, not alternatives: supplements remain recommended, and fortification covers the gap.

What Fortification Does Not Do

Fortification does not prevent all neural tube defects. Some defects arise from causes unrelated to folate, and the decline after fortification, while substantial, left most affected pregnancies unprevented. Fortification also reaches only people who eat enriched grain products. Corn masa flour, used widely in some Hispanic diets in the United States, was not part of the original requirement, and voluntary fortification of corn masa was permitted only in 2016. A defense of fortification should therefore be honest about its reach: it is a broad floor of protection, not a complete solution, and gaps in the food supply can leave some groups less protected than others.

Summary

Neural tube defects arise when the neural tube fails to close in the first month after conception, often before pregnancy is recognized. Folic acid reduces risk, as shown by a randomized trial, and mandatory fortification reaches women regardless of planning. The two main objections, masking of vitamin B12 deficiency and the sufficiency of supplements, are answered by evidence on masking and by the timing of the defect.

References

Finer, L. B., & Zolna, M. R. (2016). Declines in unintended pregnancy in the United States, 2008-2011. The New England Journal of Medicine, 374(9), 843-852. https://doi.org/10.1056/NEJMsa1506575

Honein, M. A., Paulozzi, L. J., Mathews, T. J., Erickson, J. D., & Wong, L.-Y. C. (2001). Impact of folic acid fortification of the US food supply on the occurrence of neural tube defects. JAMA, 285(23), 2981-2986. https://doi.org/10.1001/jama.285.23.2981

Mills, J. L., Von Kohorn, I., Conley, M. R., Zeller, J. A., Cox, C., Williamson, R. E., & Dufour, D. R. (2003). Low vitamin B-12 concentrations in patients without anemia: The effect of folic acid fortification of grain. The American Journal of Clinical Nutrition, 77(6), 1474-1477. https://doi.org/10.1093/ajcn/77.6.1474

MRC Vitamin Study Research Group. (1991). Prevention of neural tube defects: Results of the Medical Research Council Vitamin Study. The Lancet, 338(8760), 131-137. https://doi.org/10.1016/0140-6736(91)90133-A