Maternal and cord blood samples of 50 FGR cases (birth weight <10 percentile for gestational age as per Lubchenco's growth chart) and equal number of normal pregnancies who were occupationally non exposed to OCPs and excluding all the known high risk factors such as anemia, hypertension, antiphospholipid antibody syndrome, medical disease, dietary habit, living style, parity, and BMI. The collected samples at the time of delivery/after delivery were analyzed for OCPs levels by gas chromatography and polymorphic analysis for GSTM1/GSTT1 gene using multiplex PCR.
Significantly higher levels of 伪,尾,纬-HCH and p,p鈥?DDT were found in maternal blood and significantly higher levels of 尾 and 纬-HCH and p,p鈥?DDT were found in cord blood of FGR cases as compared to controls. The genotypic distribution of GSTM1/GSTT1 was almost similar in both the groups, but the frequency of GSTM1鈭?GSTT1鈭?(null) genotype was significantly higher in FGR cases as compared to controls (p < 0.05, OR = 6.42). When interaction between GSTM1/GSTT1 genes polymorphism-OCPs levels and birth weight (gene-environment interaction) was ascertained, a significant association was seen between 尾-HCH and GSTM1鈭?genotype with reduction in birth weight of 213 g.
Higher levels of OCPs in pregnant women may be considered as an important aetiological factor in 鈥榠diopathic鈥?FGR. GST polymorphism can influence the relationship between prenatal exposure to pesticides and FGR. The present study provides evidence that polymorphism in xenobiotic metabolising genes may modify the effect of environmental health hazards and increase the risk of FGR.