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Assessing preterm infant metal exposures in shed teeth: findings from the Developmental Impact of NICU Exposures
Wil Lieberman-Cribbin1,2,3, Emily Spear4, Chris Gennings4
1Northwell, New Hyde Park, NY, USA. wliebermancrib@northwell.edu.
Insights
This study analyzed metals in preterm infants
Area of Science:
- Environmental Health
- Neonatal Medicine
- Biomaterials Science
Background:
- Limited data exists on environmental exposures for preterm infants in neonatal intensive care units (NICUs).
- Understanding these exposures is crucial for infant health and development.
- Shed teeth offer a novel biomatrix for assessing historical exposures.
Purpose of the Study:
- To determine the timing and magnitude of a broad array of metals during gestation and NICU hospitalization.
- To utilize shed teeth as a biomatrix for metal exposure assessment.
- To link metal concentrations to specific developmental periods in utero and in the NICU.
Main Methods:
- Analysis of 18 metals (e.g., Al, Pb, Zn) in shed teeth from 138 preterm infants using laser ablation.
- Utilizing the neonatal line in teeth to estimate prenatal and postnatal age.
- Employing linear mixed-effects models to evaluate changes in metal ratios across prenatal/postnatal periods and weeks.
Main Results:
- Metal levels were successfully linked to developmental weeks for 138 participants (median gestational age: 27 weeks).
- Postnatal levels of Pb, Ba, Sn, Zn, Mn, Al, Mg, and Cu were generally lower than prenatal levels.
- Specific metals like Al and Ba showed higher prenatal ratios, while Zn and Mn exhibited distinct peaks during specific prenatal weeks.
Conclusions:
- This study provides the first comprehensive evaluation of metals during gestation and NICU stay in preterm infants using shed teeth.
- The findings suggest that postnatal metal exposures in the NICU are generally lower than prenatal exposures.
- This biomatrix approach offers unique insights into exposure sources and potential influences on clinical outcomes.
Background:
Limited data exist on environmental exposures experienced by preterm infants in the neonatal intensive care unit (NICU).
Objective:
To determine the timing and magnitude of a broad array of metals during gestation and NICU hospitalization using shed teeth as a biomatrix.
Methods:
Teeth from participants in the Developmental Impact of NICU Exposures (DINE) cohort were analyzed for Al, As, Ba, Bi, Ca, Cd, Co, Cu, Li, Mg, Mn, Mo, Ni, Pb, Rb, Sn, Sr, and Zn using laser ablation techniques. The neonatal line was used to assign prenatal and postnatal age estimates to metal concentrations relative to Ca in discrete regions of teeth. We evaluated changes in metal ratios across the prenatal/postnatal periods and measurement week using linear mixed effects models and calculated estimated marginal means for each week in the prenatal and postnatal periods.
Results:
Metals were measured in 138 participants (median gestational age: 27, IQR 25-28 weeks) and linked to developmental weeks in utero or in the NICU. Averaged differences across the prenatal and postnatal periods decreased for Pb, Ba, Sn, Zn, Mn, Al, Mg, and Cu, and increased for Sr, Rb, and Li. Prenatal ratios were highest and larger than postnatal ratios in weeks 28-30 for Al and Ba. Prenatal Zn was highest in weeks 24 and 30 and Mn was highest during weeks 24 and 25.
Significance:
We provide the first comprehensive evaluation of metals during gestation and NICU stay in preterm infants, with postnatal levels generally lower than prenatal levels for most metals. This approach has relevance to ascertaining exposure sources, influences on clinical outcomes, and provides insights not previously possible in cohorts where all third-trimester exposures were incurred in utero.
Impact:
This study represents the first analysis of metals spanning gestation and the NICU stay in a preterm infant population using shed teeth as a biomatrix. Metal levels differentiated across the third trimester prenatally or postnatally in the NICU provide unique insights for understanding exposure sources and health outcomes.
