Correlation between Cadmium and Lead Levels in Maternal Blood Samples with Preterm Labor
Abstract
Background: Globally, an estimated one million children under the age of five die every year as a direct result of preterm birth and its associated consequences. Preterm birth has a complicated and multi-factored etiology. Prenatal exposure to heavy metals is widely believed to have a significant role in the genesis of preterm birth.
Aim of study: To estimate the association between maternal blood lead and cadmium on one hand, and preterm labor on the other hand.
Study design and setting: This is a case-control study that included 100 patients (50 cases and 50 controls) and was conducted in Baghdad Teaching Hospital/ Medical city, Baghdad in the period from the 1st of January 2022 to the 30th of November 2022.
Methodology:
Preterm birth was defined as birth at gestational age less than 37 weeks and term pregnancy³37 completed weeks. Testing for blood lead and cadmium levels was conducted in the Iraqi Poisoning Consultation Center of Baghdad Medical City.
Results:
The mean blood lead of the studied sample was 20.8 μg/dl ± 5.4. The mean cadmium lead was 0.26 μg/dl ± 0.08, which was significantly higher than the level considered acceptable by the World Health Organization. For blood lead, using cut-off value of 0.3 μg/dl for blood lead as accepted by the Iraqi center of toxicity), the women with preterm labor had significantly higher levels of blood lead than women with term labor. A cut-off value of 0.3 μg/dl had a sensitivity of 48%, specificity of 100%, postivie predictive value of 100%, negative predictive value of 65.7%, and accuracy of 74%.
As for blood Cd, using cut-off value of 0.3 μg/dl for blood cadmium as accepted by the Iraqi center of toxicity), the women with preterm labor had significantly higher levels of blood Cadmium than women with term labor. a sensitivity of 68%, specificity of 100%, postivie predictive value of 100%, negative predictive value of 75.7%, and accuracy of 84%.
Conclusion:
- Maternal blood lead and cadmium levels were extremely higher than the level considered acceptable by the World Health Organization and considerably higher than other studies.
- Moreover, the present study found that both studied heavy metals may contribute as risk factors of preterm labor.