Table 2

Association between maternal occupational exposure to polycyclic aromatic hydrocarbons (PAHs) and small for gestational age (SGA) offspring, National Birth Defects Prevention Study, 1997–2002

Crude analysisAdjusted analysis*
SGA
n
Not SGA
n
OR95% CISGA
n
Not SGA
n
OR95% CI
Dichotomous Exposure
 No PAH exposure20424801.0(Reference)20424801.0(Reference)
 Any PAH exposure171022.0(1.2 to 3.5)171022.2(1.3 to 3.8)
Cumulative Exposure†‡
 No PAH exposure (0)20424801.0(Reference)20424801.0(Reference)
 Low PAH exposure (8–205)9502.2(1.1 to 4.5)9502.5(1.2 to 5.3)
 High PAH exposure (206–3086)8521.9(0.9 to 4.0)8521.9(0.9 to 4.2)
  • *Adjusted for maternal age.

  • †Cumulative exposure (unit-hours) was estimated by: (weighted intensity in µg/m3/h)×((exposure frequency in hrs/week)/(40 h/week))×((hours worked per week)/(7 days per week))×(number of days worked from 1 month before conception to delivery).

  • ‡Cumulative exposure measured in μg/m3-h.