Elsevier

Public Health

Volume 116, Issue 2, March 2002, Pages 89-94
Public Health

Articles
Association of low maternal education with neural tube defects in Colorado, 1989–1998

https://doi.org/10.1038/sj.ph.1900821Get rights and content

Abstract

Despite increasing use of folate prior to conception, neural tube defects remain among the most common birth defects in the United States.

The Study objective was to investigate the maternal and child characteristics associated with having an infant born with a neural tube defect (NTD) in Colorado between 1989 and 1998.

Data were derived from a population-based case control study of all live-born infants in Colorado from 1989 to 1998 (n = 551 285), utilizing birth certificate records and a statewide neural tube defect registry. Chi-square analysis and multiple logistic regression were used to assess the strength of association between sociodemographic characteristics and the main outcome measure, the birth of a child with an NTD. Final analysis was limited to those children born to mothers who themselves were born in either the United States or Mexico.

In this ten-year period, there were 251 confirmed cases of NTDs in Colorado, 224 of whom were born to women who were born in either the United States or Mexico. Significant bivariate associations were found between NTDs and the following: female sex of the child, lower maternal age, maternal country of birth in Mexico, and maternal education less than tenth grade. The single strongest predictor of having a child with an NTD was low maternal education (adjusted OR 1.8, 95% CI 1.1–3.1).

Low maternal education is an important predictor of having a child with an NTD. In order to further reduce the incidence of neural tube defects, interventions should target women of low educational status. Public Health (2002) 116, 89–94

Introduction

Neural tube defects (NTDs) are among the most common congenital birth defects in the United States, placing a substantial economic burden on the US health care system1 and an emotional burden on the families affected. Significant advances have been made over the past 10 years in identifying aetiologic factors. Folic acid supplementation before conception and during the first four weeks of pregnancy has the potential to decrease the incidence of neural tube defects by at least half.2, 3 However, wide variations in incidence based on geography, time of year, race, and ethnicity suggest a complex interaction of multiple environmental and genetic factors.4 Maternal factors that have been associated with an increased risk of NTD-affected pregnancies include poor diet,1, 2 diabetes,4 pesticide exposures,5 poverty6, 7 fever in the first trimester,8 stress,9 use of folic acid antagonists,10 and obesity.11

Ethnicity also appears to play a role in the incidence of NTDs, but the causative mechanism has not been defined.12 NTDs occur with a much higher incidence in Mexico than in the United States.4 Several studies have shown that people of Mexican heritage residing in the United States are at greater risk of having a child with a NTD than are non-Hispanic white people.12, 13, 14 In addition, one study has suggested that Latin women born in Mexico are at significantly greater risk of giving birth to a child with an NTD than are Latin women born in the United States, or non-Latin white women.13 However, in some populations, maternal country of birth in Mexico does not appear to be a risk factor.14 Low maternal education has also been associated with an increased likelihood of having a child with an NTD,6, 13, 14 although its relationship with maternal country of birth and ethnicity has not been clearly defined. Given the rapidly increasing Latin population in the United States, it is important to further delineate factors associated with the increased incidence of NTDs seen in some Hispanic populations.

We utilized birth registry and birth defect data in Colorado from 1989 to 1998 in a case control study to evaluate maternal factors associated with infants born with NTDs. Specifically, we wished to examine the association of maternal education, ethnicity, and country of birth with NTDs, in a state with a significant proportion of Hispanic women, many of whom are first generation immigrants from Mexico.

Section snippets

Methods

We conducted a population-based, case-control study on women who gave birth to children with neural tube defects in Colorado from 1989 to 1998. We used data from Colorado vital records (birth certificates), which document every live birth in the state, and from the Colorado Responds to Children with Special Needs (CRCSN) neural tube defect (NTD) registry, a separate database that records all live children born with NTDs. The Colorado Department of Public Health and Environment (CDPHE) maintains

Results

Between 1989 and 1998, 251 infants with neural tube defects were born in Colorado; 224 were born to mothers who themselves were born in the United States or Mexico and had complete information on the birth certificate for the risk factors of interest. Of these 224 infants, 30 had anencephaly, 150 spina bifida, and 40 encephalocele/meningomyelocele (Table 1). The number of NTDs per year ranged from a minimum of 14 in 1993 to a maximum of 32 cases in 1998. Two infants had more than one of these

Discussion

These population-based data demonstrate the complex interplay of maternal country of birth, ethnicity, and educational level with NTDs. A large population-based study in California demonstrated an increased odds ratio for NTDs in children of Mexican-born women, but not in US-born Hispanic women. The increased risk persisted even after controlling for education.13 In contrast, a population-based study done in Texas showed an increased incidence of neural tube defects among Hispanic babies but no

Acknowledgements

We wish to acknowledge Dennis Lezotte, PhD, and Ned Calonge, MD, MPH of the University of Colorado Dept of Preventive Medicine and Biometrics for help with study design and data analysis; and Russel Rickard of Colorado Responds to Children with Special Needs, at the Colorado Department of Public Health and Environment, for assistance with the Colorado neural tube defects database.

References (30)

  • JH Perlow

    Comparative use and knowledge of preconceptional folic acid among Spanish and English-speaking populations in Phoenix and Yuma, Arizona

    Am J Obstet Gynecol.

    (2001)
  • Prevention of neural tube defects: results of the Medical Research Council Vitamin Study

    Lancet

    (1991)
  • AE Czeizel et al.

    Prevention of the first occurrence of neural tube defects by periconceptional vitamin supplementation

    New Engl J Med.

    (1992)
  • LD Botto et al.

    Neural tube defects

    New Engl J Med.

    (1999)
  • GM Shaw et al.

    Maternal pesticide exposure from multiple sources and selected congenital anomalies

    Epidemiology.

    (1999)
  • CR Wasserman et al.

    Socioeconomic status, neighborhood social conditions, and neural tube defects

    Am J Public Health

    (1998)
  • J Little et al.

    Socioeconomic status and occupation

  • GM Shaw et al.

    Maternal illness, including fever, and medication use as risk factors for neural tube defects

    Teratology

    (1998)
  • SL Carmichael et al.

    Maternal life event stress and congenital anomalies

    Epidemiology

    (2000)
  • GM Shaw

    Risk for neural tube defect affected pregnancies among women of Mexican descent and white women in California

    Am J Public Health

    (1997)
  • S Hernandez-Diaz et al.

    Folic acid antagonists during pregnancy and the risk of birth defects

    New Engl J Med.

    (2000)
  • GM Shaw et al.

    Risk of neural tube defect-affected pregnancies among obese women

    JAMA

    (1996)
  • J Little et al.

    Ethnic origin and migration

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