Prevention of neural tube defects by periconceptional use of folic acid.

Abstract

1. Mohammad Masud Iqbal, MD, MPH, MSPH* 1. 2. *Department of Epidemiology & International Health, School of Public Health, The University of Alabama, Birmingham, AL. After completing this article, readers should be able to: 1. Identify today’s most common vitamin deficiency in women. 2. List the etiology of neural tube defects (NTDs) and its relationship with folic acid. 3. Describe how up to 70% of NTDs can be prevented among women of child-bearing age. 4. Name the diagnostic methods used to detect NTDs. 5. Describe the relationship between increased intake of folic acid and vitamin B12 deficiency. Birth defects are the leading cause of infant mortality and a major contributor to heightened morbidity in the United states. The basic definition of a birth defect is a structural abnormality present at birth. Infant mortality attributable to birth defects has not declined as rapidly as overall infant mortality; from 1968 to 1995, the proportion of infant mortality due to birth defects increased from 14.5% to 22.2%. It has been estimated that approximately 20% to 25% of all birth defects are due to gene mutations, 5% to 10% to chromosomal abnormalities, and another 5% to 10% to exposure to a known teratogenic agent (such as prescription drugs, chemicals, or radiation) or a maternal factor. Together, these percentages account for only 30% to 40% of birth defects, leaving the etiology of more than 50% unexplained. It has been speculated that environmental factors account for no more than 10% of all congenital anomalies. Genetic factors are responsible for 30% of pediatric hospital admissions. Birth defects rank somewhere between second and fifth among causes of death in children younger than 1 year of age; 3% to 4% of infants in their first year of life are diagnosed as having major birth defects. Of the 120,000 to 150,000 infants born with serious birth defects each year, approximately 6,000 die during their first 28 days of life and another 2,000 die before reaching their first birthdays. In …