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The relation between small size for gestational age and the sex ratio of children with birth defects

L J Paulozzi1

  • 1National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia 30341, USA. LBP4@cdc.gov

Teratology
|February 13, 2001
PubMed

Insights

Infants with birth defects often are small for gestational age (SGA). This study found male-dominant birth defects correlate with lower SGA percentages, suggesting genetic links, while others may be environmental.

Area of Science:

  • Pediatric genetics
  • Birth defect epidemiology
  • Perinatal health

Background:

  • Infants with birth defects exhibit a higher incidence of being small for gestational age (SGA).
  • A relationship between SGA percentage and sex distribution in infants with various birth defects was investigated.
  • Data were sourced from the Metropolitan Atlanta Congenital Defects Program (1968-1998).

Purpose of the Study:

  • To examine the correlation between sex ratios and SGA percentages across different types of birth defects.
  • To differentiate potential genetic versus environmental influences on birth defect patterns.

Main Methods:

  • Calculated the correlation between the percentage of males and the percentage of SGA infants for 44 isolated defect types.
  • Analyzed defects separately for male-dominant and female-dominant categories.

Main Results:

  • A significant negative correlation (-0.47, P < 0.01) was observed between sex ratio and SGA in male-dominant defects.
  • Female-dominant defects showed a non-significant positive correlation (0.20, P > 0.05) with SGA.
  • Male-dominant defects were more frequently associated with <15% SGA and pronounced sex-based risk differences.

Conclusions:

  • Findings support a genetic basis for skewed sex ratios in male-dominant birth defects.
  • Defects with sex ratios near 1 may indicate lower inheritance risk and potentially acquired or environmental origins.
  • High SGA percentages alongside near-unity sex ratios could serve as markers for environmentally influenced birth defects.
Abstract

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