Background:

In Mexico, there is a paucity of evidence on the magnitude of prenatal exposure to metals.

Objective:

To estimate the concentration of arsenic, cadmium, manganese and lead in umbilical cord blood (UCB) and its association with maternal blood concentrations during pregnancy and delivery.

Material and methods:

Metal concentration in maternal blood was analyzed during pregnancy (n = 901), delivery (n = 732) and in UCB (n = 512) from participants of the PROGRESS cohort residing in Mexico City. The association between concentrations in UCB and maternal biomarkers was analyzed using generalized linear models, adjusted for relevant covariates.

Results:

Mean concentrations (μg/L) of lead, arsenic and manganese in UCB were 27.14 (25.28-29.14), 0.77 (0.71-0.84) and 42.60 (40.45-44.83), respectively. Cadmium concentration could not be estimated because 86.2% of measurements were below the detection limit. Lead and manganese concentrations in UCB were significantly associated with maternal biomarkers during pregnancy and delivery; at delivery, association was only observed with arsenic.

Conclusions:

Prenatal exposure to toxic metals in sensitive periods of organogenesis shows a neglected public health problem. Biomonitoring of the population and establishment of regulations aimed at providing care to vulnerable populations is required.