Early umbilical cord clamping contributes to elevated blood lead levels among infants with higher lead exposure.
OBJECTIVE
To investigate whether infant iron status, modified by umbilical cord clamping time and infant feeding mode, affected infant blood lead concentration at 6 months of age.


METHODS
Participants were a subset of women and their infants randomized to receive early (10 seconds) or delayed (2 minutes) umbilical cord clamping and were monitored to 6 months postpartum in Mexico City. Iron and lead status was analyzed in maternal, placental, and 6-month infant blood samples. Baseline maternal lead exposure data and infant feeding data at 2, 4, and 6 months were collected.


RESULTS
In the total sample, maternal blood lead concentration, infant ferritin, and breast-feeding practices predicted infant blood lead concentration. Among infants with higher placental blood lead concentration and breast-fed infants not receiving any iron-fortified formula or milk at 6 months, early clamping increased infant blood lead concentration, an effect mediated in part via decreased infant iron status.


CONCLUSIONS
Early cord clamping, by decreasing infant iron status, contributes to higher blood lead concentrations at 6 months of age among infants at high risk.
Chaparro
Camila M
CM
Department of Nutrition, Program in International and Community Nutrition, University of California, Davis, California 95616-8669, USA.
Fornes
Raymond
R
Neufeld
Lynnette M
LM
Tena Alavez
Gilberto
G
Eguía-Líz Cedillo
Raúl
R
Dewey
Kathryn G
KG
D001942:Breast Feeding; D002516:Ceramics / Q000737:chemistry; D003250:Constriction; D004781:Environmental Exposure; D005260:Female; D005293:Ferritins / Q000097:blood; D005312:Fetal Blood / Q000737:chemistry; D006801:Humans; D007231:Infant, Newborn; D007854:Lead / Q000097:blood*; D008297:Male; D008423:Maternal Age; D008431:Maternal-Fetal Exchange; D010920:Placenta / Q000098:blood supply / Q000737:chemistry; D011247:Pregnancy; D012044:Regression Analysis; D013997:Time Factors; D014470:Umbilical Cord
D007854:Lead; D005293:Ferritins