Objective: Little information is available on the associations of combined maternal-infant genetic susceptibility, environmental exposures and reproductive outcomes, especially in the Chinese population. The aim of this study was to investigate whether the polymorphisms of combined maternal-infant metabolic genes, CYP1A1 HincII, CYP1A1 MspI, GSTT1 and GSTM1 affect the association of maternal exposure to organic solvents with gestational age.
Methods: 1113 mother-infant pairs were enrolled from the Beijing Yanshan Petrochemical Corporation between June 1997 and June 2002, of which 546 mothers were exposed to organic solvents and 567 were not. Multiple linear regression models were used to estimate the combined maternal-infant gene effects, and to characterise combined maternal-infant genetic susceptibility to organic solvents in relation to gestation.
Results: Organic solvent exposure was significantly related to shortened gestation (-1.2 weeks, 95% CI-1.6 to -0.9). Additionally, combined maternal-infant genotypes including Ile/Ile462-Ile/Ile462 (-0.6 weeks, 95% CI-0.9 to -0.4) in CYP1A1 HincII and absent-absent in GSTT1 (-0.4 weeks, 95% CI-0.9 to -0.3) were significantly associated with shorter gestation. When considering both organic solvent exposure and combined maternal-infant genotypes, the largest associations were found among exposed women with the absent-absent genotype (-1.5 weeks, 95% CI -1.8 to -1.2) in GSTT1 and the Ile/Ile462-Ile/Ile462 genotype (-1.5 weeks, 95% CI -1.8 to -1.2) in CYP1A1 HincII, suggesting that combined genotypes would modify the effect of exposure to organic solvents on gestation.
Conclusions: This study demonstrates the role of combined maternal-infant genotypes in modifying the adverse effects of organic solvent exposure on gestation, and the maternal-infant interaction of four genes was determined.