Should primary care clinicians screen asymptomatic children and asymptomatic pregnant women for elevated blood level levels?

In this updated 2019 review, The United States Preventive Services Task Force concludes that the current evidence is insufficient to recommend screening for elevated blood lead levels in asymptomatic children and asymptomatic pregnant women (I statement). This recommendation is essentially unchanged from the 2006 recommendation. (LOE = 2c)

US Preventive Services Task Force. Screening for elevated blood levels in children and pregnant women. US Preventive Services Task Force recommendation statement. JAMA 2019;321(15):1502-1509.  [PMID:30990556]

Practice guideline

Government

Population-based

The task force found 24 studies (n = 11,433) that evaluated interventions related to screening for elevated blood lead levels in children and pregnant women. No studies directly evaluated the benefits or harms of screening vs no screening. The authors found no questionnaires or other clinical prediction tools that can accurately identify which asymptomatic children and pregnant women are at risk of elevated blood levels. In addition, counseling and nutritional interventions or residential lead hazard control techniques have not been shown to reduce blood lead levels in asymptomatic children. Current evidence of chelation therapy has not found any consistent benefit, with some studies actually showing a significant decrease in linear growth and poorer cognitive outcomes in children treated with chelation. The American Academy of Family Physicians (AAFP) recommends against routine screening for elevated blood lead levels in asymptomatic children aged 1 to 5 years at average risk, and found insufficient evidence on screening children at increased risk. Similarly, the AAFP recommends against routine screening of pregnant women without symptoms. The American Academy of Pediatrics recommends screening for children living in high-prevalence areas; for children living in homes at risk for lead hazards; and for children who are immigrants, refugees, or internationally adopted. The American College of Obstetricians and Gynecologists recommends targeted screening during pregnancy for women with risk factors for lead exposure. Medicaid currently requires lead screening at age 12 months and 24 months, and at least once at 36 months to 72 months, if not previously screened.