Association Of Lead With Maternal Stress In Pregnant Women

Abstract

Introduction: Neuro-developmental effects of in utero exposure to lead were documented in previous studies, however, limited studies focused on the association between lead exposure and maternal stress during pregnancy among pregnant women with non-occupational lead exposure. Methods: A total of 1931 pregnant women were investigated using stratified-cluster-sampling in Shanghai in 2010, and women were recruited during late pregnancy (28-36 gestational weeks). Maternal life event stress and emotional stress were assessed using “Event-Stress-Scale-for-Pregnant-Women” and “Symptom-Checklist-90-R-Scale” (SCL-90) respectively. Maternal whole blood lead concentration was determined. Other data on covariates were collected from maternal interviews and from medical records. Results: Mean maternal blood lead level was 4.33μg/dL (SD 1.71, range 0.8–14.8 μg/dL). After adjusting for potential confounders, a nonlinear relationship was observed between blood lead and total scores of SCL-90. When blood lead levels below 2.6μg/dL, the total scores of SCL-90 increased with increasing blood lead levels (β=4.19, p=0.027), however, when above 2.6μg/dL, the total scores of SCL-90 did not significantly increase with increasing blood lead levels (β=0.44 ,p=0.233), the trend difference was statistically significant (p=0.024).The similar patterns can be observed for the subscales of SCL-90 such as somatization, depression, anxiety and psychoticism. Conclusions: Our findings suggested a positive association between lead and emotional stress under low-lead-exposure conditions during pregnancy, but a non-significant association under high-lead-exposure conditions.