Maternal concentration of dichlorodiphenyl dichloroethylene (DDE) and initiation and duration of breast feeding

Authors

  • Wilfried Karmaus,

    Corresponding author
    1. Department of Epidemiology, Michigan State University, East Lansing, MI, USA
      Wilfried Karmaus, MD, MPH, Professor, Department of Epidemiology and Biostatistics, The Arnold School of Public Health, University of South Carolina, 800 Sumter Street, Columbia, SC29208-001, USA. E-mail: karmaus@gwm.sc.edu
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  • Susan Davis,

    1. Department of Epidemiology, Michigan State University, East Lansing, MI, USA
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  • Christopher Fussman,

    1. Department of Epidemiology, Michigan State University, East Lansing, MI, USA
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  • Kevin Brooks

    1. Department of Epidemiology, Michigan State University, East Lansing, MI, USA
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Wilfried Karmaus, MD, MPH, Professor, Department of Epidemiology and Biostatistics, The Arnold School of Public Health, University of South Carolina, 800 Sumter Street, Columbia, SC29208-001, USA. E-mail: karmaus@gwm.sc.edu

Summary

Dichlorodiphenyl dichloroethylene (DDE) has been shown to reduce the duration of breast feeding in two studies. In addition to duration, we examined whether DDE lowers the initiation of breast feeding. Between 1973 and 1991, the Michigan Department of Community Health conducted three surveys to assess polychlorinated biphenyls (PCBs) and DDE serum concentrations in Michigan anglers. Through telephone interviews with parents, we retrospectively ascertained information on breast feeding. Based on repeated maternal serum measurements between 1973 and 1991, we arrived at the level of exposure at the time of delivery by extrapolating PCB and DDE serum levels. One mother may have contributed more than one child; however, serum concentrations varied between children from the same mother. The maternal DDE and PCB serum concentrations were categorised as follows: 0 to < 5 µg/L, 5 to < 10 µg/L, ≥ 10 µg/L. Repeated measurement models and survival analyses were used to determine the relationship between DDE and PCBs and characteristics of breast feeding while controlling for cohort effects, maternal age at delivery, education, and smoking during pregnancy. We focused on 176 pregnancies of 91 mothers who had maternal exposure information and gave birth between 1969 and 1995.

Initiation of breast feeding was lowered by 39.5% and duration shortened by 66.4% in children of mothers who smoked during pregnancy. In children of non-smoking mothers, the incidence ratio for breast-feeding initiation was 0.45 [95% CI 0.15, 0.94] and 0.42 [95% CI 0.10, 1.03] when maternal DDE concentrations were 5 to < 10 µg/L and ≥ 10 µg/L respectively, compared with the lowest DDE exposure group. In these offspring (of non-smoking mothers), breast-feeding duration was shorter when DDE concentrations were higher: 13 weeks for ≥ 10 µg/L DDE, compared with 21.7 weeks for lower DDE. We did not detect any association between PCBs and breast feeding. In the absence of the distorting effects of maternal smoking, DDE exposure may decrease initiation and duration of breast feeding.

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