Impact Of Prenatal Exposure Of Organochlorine Pesticides On Birth Outcomes

Objectives:To study the present organochlorine pesticides exposure situation of pregnant women and fetus in Yancheng city by epidemiology investigation and biological sample detection. To explore whether organochlorine pesticides can affect birth outcomes by interfering thyroid hormones levels of newborns. In a word, this study was designed to provide the theoretical basis for further health hazard evaluation and policy making for environment protection, as well as to provide a scientific reference for conducting researches related to prevent the prenatal exposure to organochlorine pesticides.Method:Field study was conducted in Yancheng city according to previous useage of organochlorine pesticides. The content of organochlorine pesticides in the peripheral serum of pregnant women and umbilical cord serum were detected by HRGC-HRMS to evaluate the organochlorine pesticides burden of both mothers and fetus. We detected the thyroid hormones levels of cord serum, investigated the condition of birth outcomes together with the exposure situation of organochlorine pesticides and questionnaire to explore whether organochlorine pesticides can affect birth outcomes by interfering thyroid hormones levels of newborns.Results:(1) Our study detected 11 kinds of organochlorine pesticides and the detectable rates of HCB,β-HCH and p.p'-DDE were relatively higher. The detectable rates of HCB,β-HCH and p,p'-DDE in peripheral serum of pregnant women were 81.78%,84.21% and 89.47% respectively, and the detectable rates in cord serum were 53.85%,74.49% and 81.38% respectively. (2) The contents of HCB,β-HCH and p,p'-DDE were higher in the peripheral serum of pregnant women than in the cord serum. (3)β-HCH 0=0.421,P<0.01) and p,p'-DDE (r=0.288, P<0.01) in the two kinds of serum had positive correlation. (4)We hadn't found any relationship between organchlorine levels and newborns'development status at birth. (5) The multiple linear regressions model results showed that the content ofβ-HCH in cord serum was associated with FT4 and TSH after controlling the other confounders in multiple linear regression models (P< 0.05). (6) Among the 247 newborns,12 of them were premature delivery,7 of them were low birth weight. The results of multiple factors analysis showed that levels of FT3 and FT4 in the cord serum had an effect on the birth weight of newborns after controlling the other confounders (P<0.05)Conclusions:(1) In the 11 kinds of organochlorine pesticides, HCB, P-HCH and p,p'-DDE had a higher detectable rates in the peripheral serum of pregnant women and umbilical cord serum and this may be due to half-time of organochlorine pesticides and the metabolic mechanism of the body. (2) The amount of organochlorine pesticides in maternal and neonatal serum had positive correlation. Furthermore, the contents of organochlorine pesticides were lower in the cord serum. So, organochlorine pesticides could transfer through placental and placental barrier limited the transfer in some degree. (3) Organochlorine pesticides might affect birth outcomes by interfering thyroid hormones levels of newborns.