Table 4

Prevalence of cumulative maternal occupational exposure to solvents during the periconceptional period* and risk of gastroschisis in offspring, National Birth Defects Prevention Study, USA, 1997–2011

Solvent classes§Cases (n=879)†Controls (n=7817)†UnadjustedAdjusted‡
N %N %OR95% CIOR95% CI
Any solvents Ptrend =0.68 Ptrend =0.79
 No exposure¶813 (92.7%)7233 (92.6%)RefRef
 Level 114 (1.6%)193 (2.5%)0.640.37 to 1.110.680.38 to 1.20
 Level 227 (3.1%)191 (2.4%)1.260.83 to 1.891.370.89 to 2.12
 Level 323 (2.6%)194 (2.5%)1.050.68 to 1.630.960.60 to 1.51
Aromatic solvents Ptrend =0.69 Ptrend =0.66
 No exposure¶859 (97.8%)7651 (97.9%)RefRef
 Level 15 (0.6%)54 (0.7%)0.830.33 to 2.071.080.41 to 2.84
 Level 27 (0.8%)54 (0.7%)1.160.52 to 2.551.500.64 to 3.52
 Level 37 (0.8%)54 (0.7%)1.160.52 to 2.550.980.43 to 2.24
Chlorinated solvents Ptrend =0.58 Ptrend =082
 No exposure¶821 (93.6%)7311 (93.6%)RefRef
 Level 111 (1.3%)167 (2.1%)0.590.32 to 1.080.610.32 to 1.15
 Level 224 (2.7%)167 (2.1%)1.280.83 to 1.981.410.89 to 2.24
 Level 321 (2.4%)167 (2.1%)1.120.71 to 1.770.970.59 to 1.54
Stoddard solvents Ptrend =0.95 Ptrend =0.37
 No exposure¶858 (97.8%)7658 (98.0%)RefRef
 Level 17 (0.8%)51 (0.7%)1.230.55 to 2.710.930.41 to 2.14
 Level 28 (0.9%)54 (0.7%)1.320.63 to 2.791.090.50 to 2.38
 Level 34 (0.5%)53 (0.7%)0.670.24 to 1.870.520.18 to 1.48
  • Ptrend = Wald p value for testing linear trend of the tertile betas.

  • *One month before conception through 3 months after conception.

  • †Missing cases/controls varied from four to seven mothers across exposures because exposure could not be assigned or cumulative exposure could not be calculated.

  • ‡Adjusted for maternal age at delivery as a continuous variable (no missing values).

  • §Based on tertiles of the exposed controls.

  • ¶No exposure for outcome under analysis.