Effects of Lead and Other Metals on Pregnancy Outcomes

Society’s industrialization and constant need for new products and components have increased the number and concentration of toxic substances that women are exposed to in their environment and workplaces. For decades, metal toxicity has remained a topic of concern for its effects on pregnant women. Although the level of exposure to many toxic metals has decreased sharply, research has revealed the impact of low-level metal exposure on different aspects of pregnancy. Lead is one of the toxic metals for which the effects on the human reproductive system have been intensively studied. The US Centers for Disease Control and Prevention have recommended a blood lead level of < 5.0 mg/dl as a screening action guideline in pregnant women. However, many studies have shown the adverse effects of lead on several human reproductive outcomes, such as low birth weight, preterm rupture of the membrane, and pregnancy hypertension, even at the ‘acceptable’ level of blood lead. This supports a reappraisal of the ‘safe’ or ‘acceptable’ level. We aimed to conduct a review of our several-year-long longitudinal study on prenatal metal exposure and pregnancy outcomes.