Maternal Exposure to Potentially Toxic Metals and Birth Weight: Preliminary Results from the DSAN-12M Birth Cohort in the Recôncavo Baiano, Brazil

Int J Environ Res Public Health. 2023 Jun 23;20(13):6211. doi: 10.3390/ijerph20136211.

Abstract

Prenatal exposure to potentially toxic metals (PTM) may impair fetal growth (FG). We investigated the relationship between maternal exposure to lead (Pb), cadmium (Cd) and manganese (Mn) and birth weight (BW) of 74 newborns. Blood was collected during the second trimester of pregnancy to determine Pb (PbB) and Cd (CdB), while hair (MnH) and toenails (MnTn) were used for Mn. Samples were analyzed by graphite furnace atomic absorption spectrophotometry (GFAAS). Sociodemographic and BW data were collected from questionnaires and maternity records, respectively. The medians (P25th-P75th) of PbB, CdB, MnH, and MnTn were, respectively, 0.9 (0.5-1.8) µg/dL; 0.54 (0.1-0.8) µg/L; 0.18 (0.1-0.4) µg/g; and 0.65 (0.37-1.22) µg/g. The means (standard deviation) of birth weight according to sex were 3067 (426.3) and 3442 (431) grams, respectively, for girls and boys. MnTn presented an inverse correlation with the BW/gestational age ratio for girls (rho = -0.478; p = 0.018), suggesting the effect of sex modification. Although BW correlation with CdB was not statistically significant, hierarchical linear regression (beta = -2.08; 95% CI-4.58 to 0.41) suggested a fetotoxic effect. These results confirmed the threat PTMs may represent and the need for more extensive research to elucidate their role in inadequate FG in developing countries.

Keywords: birth weight; fetal growth; potentially toxic metals (PTM); sex-specific effect of PTMs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Birth Cohort
  • Birth Weight
  • Brazil / epidemiology
  • Cadmium / toxicity
  • Environmental Exposure* / analysis
  • Female
  • Heavy Metal Poisoning
  • Humans
  • Infant, Newborn
  • Lead / toxicity
  • Male
  • Manganese
  • Maternal Exposure* / adverse effects
  • Pregnancy

Substances

  • Lead
  • Cadmium
  • Manganese

Grants and funding

This study was supported by grants from the Fundação de Amparo à Pesquisa do Estado da Bahia (FAPESB-PPSUS Edital no. 2/2020, pedido no. 4393/2020) and the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq Universal Processo No. 421550/2018-0). H.A.F.B., J.V.A.S. and F.d.S.C. are recipients of scholarships from CNPq; N.R.d.S., V.O.M. and E.M.P. are recipient of scholarships from FAPESB; and E.A.G.J. is a recipient of a scholarship from Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES).