Managing Elevated Lead Levels in Pregnancy

August 17, 2012

Because lead easily crosses the placenta, elevated lead levels in pregnancy have been associated with gestational hypertension, spontaneous abortion, low birth weight, and impaired neurodevelopment. In a new Committee Opinion, The American College of Obstetricians and Gynecologists has reviewed screening and management policies for elevated lead levels in pregnancy.

Exposure to high levels of lead can be associated with serious adverse effects, including delirium, seizures, stupor, coma, and possibly death. Hypertension, peripheral neuropathy, ataxia, tremor, headache, loss of appetite, weight loss, fatigue, muscle and joint aches, changes in behavior and concentration, gout, nephropathy, lead colic, and anemia can also be caused by lead toxicity. Long-term exposure to low levels of lead can result in cognitive decline, hypertension and other cardiovascular effects, decreased renal function, and reduced fertility.

Because lead easily crosses the placenta, elevated lead levels in pregnancy have been associated with gestational hypertension, spontaneous abortion, low birth weight, and impaired neurodevelopment. In a new Committee Opinion, The American College of Obstetricians and Gynecologists has reviewed screening and management policies for elevated lead levels in pregnancy.1

Universal screening for elevated lead levels is not recommended, but a risk assessment for lead exposure should occur as early in the pregnancy as possible and blood lead testing is appropriate if even 1 risk factor is discovered. If a pregnant or lactating patient has a blood lead level of 5 micrograms/dL or higher, identify the source of lead exposure, counsel her about the importance of avoiding further exposure, recommend calcium (500 mg/d) and iron (60 mg/d) supplementation to help decrease lead levels, and order confirmatory and follow-up blood lead testing per the CDC’s recommended schedule.2 If blood lead levels are 45 micrograms/dL or higher, referral to a clinician experienced in managing lead toxicity and high-risk pregnancy is appropriate.

In most cases, breastfeeding women with blood lead levels up to 40 micrograms/dL should continue breastfeeding. The ratio of breast milk lead levels to infant blood lead levels is reported to be less than 3%.3 If the mother’s blood lead level is 40 mg/dL or higher, the mother should pump and discard her breast milk until her blood lead level has decreased to 40 micrograms/dL. Vitamin C supplementation may be useful, because increased vitamin C intake has been associated with decreased lead levels in breast milk.1

Pertinent Points:
- Although rare, lead toxicity in pregnant women is associated with gestational hypertension, spontaneous abortion, low birth weight, and impaired neurodevelopment.
- Routine screening for elevated blood lead levels is not recommended.
- Risk assessment of lead exposure should occur at the earliest contact with pregnant or lactating women, and blood lead testing should be performed if even a single risk factor is identified.

References:

1. Committee opinion no. 533: lead screening during pregnancy and lactation. Obstet Gynecol. 2012;120:416-420.
2. Centers for Disease Control and Prevention. Guidelines for the identification and management of lead exposure in pregnant and lactating women. Atlanta: CDC; 2010. Available at: http://www.cdc.gov/nceh/lead/publications/leadandpregnancy2010.pdf. Accessed August 8, 2012.
3. Gulson BL, Yui LA, Howarth D. Delayed visual maturation and lead pollution. Sci Total Environ. 1998;224:215-219.