Association Between the Plasma/Whole Blood Lead Ratio and History of Spontaneous Abortion: A Nested Cross-Sectional Study

Details

• Personal Author:
  Hernández-Avila M ; Hu H ; Lamadrid-Figueroa H ; Mercado-Garcia A ; Smith, Denise L. ; Solano-González M ; Téllez-Rojo MM ; Trejo-Valdivia B ; Wright RO
• Description:
  Background: Blood lead has been associated with an elevated risk of miscarriage. The plasmatic fraction of lead represents the toxicologically active fraction of lead. Women with a tendency to have a higher plasma/whole blood Pb ratio could tend towards an elevated risk of miscarriage due to a higher plasma Pb for a given whole blood Pb and would consequently have a history of spontaneous abortion. Methods: We studied 207 pregnant Mexico City residents during the 1st trimester of pregnancy, originally recruited for two cohorts between 1997 and 2004. Criteria for inclusion in this study were having had at least one previous pregnancy, and having valid plasma and blood Pb measurements. Pb was measured in whole blood and plasma by inductively coupled plasma mass spectrometry using ultra-clean techniques. History of miscarriage in previous pregnancies was obtained by interview. The incidence rate of spontaneous abortion was defined as the proportion of previous pregnancies that resulted in miscarriage. Data were analyzed by means of Poisson regression models featuring the incidence rate of spontaneous abortion as the outcome and continuous or categorized plasma/blood Pb ratios as predictor variables. All models were adjusted for age and schooling. Additionally, logistic regression models featuring inclusion in the study sample as the outcome were fitted to assess potential selection bias. Results: The mean number of miscarriages was 0.42 (range 0 to 4); mean Pb concentrations were 62.4 and 0.14 µg/L in whole blood and plasma respectively. Mean plasma/blood Pb ratio was 0.22%. We estimated that a 0.1% increment in the plasma/blood Pb ratio lead was associated to a 12% greater incidence of spontaneous abortion (p = 0.02). Women in the upper tertile of the plasma/blood Pb ratio had twice the incidence rate of those in the lower tertile (p = 0.02). Conditional on recruitment cohort, inclusion in the study sample was unrelated to observable characteristics such as number of abortions, number of pregnancies, blood Pb levels, age schooling, weight and height. Conclusion: Women with a large plasma/whole blood Pb ratio may be at higher risk of miscarriage, which could be due to a greater availability of placental barrier-crossing Pb. [Description provided by NIOSH]
• Subjects:
  Aging Blood Lead Occupational Health Pregnancy Safety Women
• Keywords:
  Age Groups Blood Lead Levels Blood Plasma Humans Mass Spectrometry Models Statistical Analysis
• ISSN:
  1471-2393
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  California ; Massachusetts ; OSHA Region 1 ; OSHA Region 9
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  22
• Volume:
  7
• NIOSHTIC Number:
  nn:20057358
• Citation:
  BMC Pregnancy Childbirth 2007 Sep; 7:22
• Contact Point Address:
  Héctor Lamadrid-Figueroa, Division of Program Evaluation and Biostatistics, Center for Research in Evaluation and Surveys, National Institute of Public Health, Cuernavaca, México
• Email:
  hlamadrid@insp.mx
• CAS Registry Number:
  Lead (CAS RN 7439-92-1)
• Federal Fiscal Year:
  2007
• Performing Organization:
  Harvard School of Public Health
• Peer Reviewed:
  True
• Start Date:
  20050701
• Source Full Name:
  BMC Pregnancy and Childbirth
• End Date:
  20280630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:fc67954c30fb9579edad6af408b9a1538719a5ed5772c963070538576fdd37300801c62b755dfd70eb29f3f25272d2e1335516ed9ae407b0d6c66620b0c2fe69
• Download URL:
  https://stacks.cdc.gov/view/cdc/214741/cdc_214741_DS1.pdf
• File Type:
  [PDF - 299.03 KB ]