Even levels lower than 2 µg/dL in umbilical blood linked to higher blood pressure during birth
TUESDAY, March 8 (HealthDay News) -- Low-level lead exposure, measured by umbilical blood lead levels, suggests a significant association with elevations in maternal blood pressure during labor and delivery, according to a study published online Feb. 3 in Environmental Health Perspectives.
Ellen M. Wells, Ph.D., from the Case Western Reserve University School of Medicine in Cleveland, and colleagues collected admission and maximum blood pressures of 285 women in Baltimore during labor and delivery. The umbilical cord blood lead levels were measured using inductively coupled plasma mass spectrometry. Results were adjusted according to multivariable models, which were used to evaluate concentrations of lead predicting a specified increase in response.
The investigators found that the geometric average lead level in the cord blood was 0.66 µg/dL. After adjusting for confounders, there was a 6.87 mm Hg increase in admission systolic, and 4.40 mm Hg increase in admission diastolic blood pressure for women in the highest quartile, compared to the lowest quartile of lead exposure. Values correlated for maximum blood pressure with an increase of 7.72 mm Hg in systolic, and 8.33 mm Hg in diastolic. Less than 2 µg/dL umbilical blood lead was enough to increase maternal blood pressure by one standard deviation.
"We show that the previously established association of blood lead levels with elevations in blood pressure can be replicated among pregnant women at the time of labor and delivery, extending previous findings to even lower lead exposure levels," the authors write.