Prenatal exposure profiles to Benzophenones and their impacts on thyroid hormones

Prenatal exposure to Benzophenones and their potential health impacts remain insufficiently studied, particularly among vulnerable populations such as pregnant women. The lack of research is concerning given the suspected risks these endocrine-disrupting chemicals (EDCs) may pose to neonatal health, especially in relation to thyroid hormone regulation. This study seeks to address this research gap by measuring prenatal exposure profiles to Benzophenones in women living in Algiers. Specifically, it aims to explore the associations between Benzophenone levels in umbilical cord blood and disruptions in thyroid hormone levels at the time of delivery. Additionally, the study investigates the possible link between women's exposure to specific sources and the resulting endogenous levels of Benzophenones.

This was a descriptive study carried out on 154 paired mother-newborns after gathering necessary information using a questionnaire. Umbilical cord blood was collected and TSH and thyroid hormones (FT3 and FT4) were measured by electrochemiluminescence while Benzophenones (BP-1, BP-2, and BP-3) were detected by LC-MS/MS.

BP-1, BP-2, and BP-3 were detected in 29.87 %, 0 %, and 48.05 % of analyzed samples. Mean concentrations were 0.330 and 0.787 µg/g for BP-1 and BP-3, respectively. Significant negative association was found between levels of FT3 and concentrations of BP-3 in cord blood (β= -0.237), as well as a negative association between levels of FT4 and prenatal concentrations of BP-1 (β= -1.028). Notably, prenatal exposure to Benzophenones did not exhibit significant alterations on birth outcomes. A significant association linked lower levels of BP-1 with the tendency to read ingredient labels on cosmetic products by pregnant women (P = 0.024).

In this Algerian population of parturient women, high exposure profiles to BP-1 and BP-3 through placental blood were associated with altered levels of thyroid hormones (FT4 and FT3, respectively). It appears these two compounds exert a diminishing effect on thyroid function. Such changes may involve adverse effects on maternal health and child development, especially on the nervous system.