ARE BIRTH DEFECTS IN TEXAS HIGHER ALONG THE MEXICAN BORDER

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ARE BIRTH DEFECTS IN TEXAS HIGHER ALONG THE
MEXICAN BORDER?

• Peter Langlois PhD, Mark Canfield PhD, Lucina
  Suarez PhD
• Texas Dept of State Health Services

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BACKGROUND
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METHODS

• Cases from Texas Birth Defects Registry, 1999 -
  2002
• Compared 14 border counties to remaining 240
  counties

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Texas Border Counties
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METHODS (contd)

• 92.1 of live births in border counties Hispanic,
  thus restricted all analyses to Hispanics
• Examined 165 birth defects and any reportable
  birth defect

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METHODS (contd)

• Chi-square tests to identify potential
  confounders
• Poisson regression to calculate prevalence ratio
  for border Hispanic vs non-border Hispanic for
  each defect

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METHODS (contd)

• 4 analyses
• Crude
• Adjusted for all covariates found to be
  significantly different between border and
  non-border
• Isolated cases of birth defects (crude)
• Severe cases of birth defects (crude), criteria
• Had severe procedure (surgery, repair, autopsy)
• Fetal death
• If live birth, died in first year after birth

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RESULTS

• Border (vs non-border) Hispanics significantly
• Were delivered more in 1999-2000 vs later
• Had older moms
• Had moms with more previous live births
• Had more educated moms
• Had a greater of moms born in Mexico
• Had a lower of moms with diabetes
• Had slightly higher multiple births
• Infant sex was not significantly different

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Maternal Age Among Texas Hispanics by Border
Status
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Maternal Education Among Texas Hispanics by
Border Status
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Border vs Non-border Residence Any Monitored
Birth Defect Among Hispanics
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Examples of Defects Among Hispanics Higher in
Border Areas Based on Different Analyses
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Number of Cardiovascular Defects Among Hispanics
Higher in Border Areas Based on Different Criteria
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Number of All Defects Among Hispanics Higher in
Border Areas Based on Different Criteria
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Analyses Where Defects Met Both Criteria
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(No Transcript)
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Number of All Defects Among Hispanics Lower in
Border Areas Based on Different Criteria
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CONCLUSIONS

• Hispanic mothers on the border tend to be older,
  better educated, and Mexican-born than Hispanic
  mothers elsewhere
• Overall, birth defects among Hispanics are lower
  along the border since
• Any birth defects were less prevalent
• Using either criterion to identify meaningful
  associations, more defects were lower along the
  border than higher

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CONCLUSIONS (cont)

• The defects with elevations among border
  Hispanics did not show consistent patterns, and
  are not etiologically related
• Where possible, it is useful to
• adjust for confounders and
• examine clinical subsets of cases such as severe
  cases.

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CONCLUSIONS (cont)

• It may be useful to combine criteria for
  determining meaningful associations
• Some other possible criteria
• Number of cases available
• Dose-response (distance)
• Biological plausibility / other Hill criteria
• Diagnostic practice considerations

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• Contact information
• Peter Langlois
• 512-458-7232
• peter.langlois_at_dshs.state.tx.us
• www.dshs.state.tx.us/birthdefects