Association of maternal urinary fluoride concentrations during pregnancy with size at birth and the potential mediation effect by maternal thyroid hormones: The Swedish NICE birth cohort
Artikel i vetenskaplig tidskrift, 2022

Background: Observational studies have indicated that elevated maternal fluoride exposure during pregnancy may impair child neurodevelopment but a potential impact on birth outcomes is understudied.
Objectives: To evaluate the impact of gestational fluoride exposure on birth outcomes (birth size and gestational age at birth) and to assess the potential mediating role of maternal thyroid hormones.
Methods: We studied 583 mother-child dyads in the NICE cohort in northern Sweden. Maternal fluoride exposure was assessed by measuring urinary concentrations at late pregnancy (median: 29th gestational week) using an ion selective electrode. Plasma levels of free and total thyroxine (fT4, tT4) and triiodothyronine (fT3, tT3), and thyroid stimulating hormone (TSH) were measured with electrochemiluminescence immunoassays. The infant's weight, length, head circumference, and gestational age at birth were extracted from hospital records.
Results: Median urinary fluoride concentration was 0.71 mg/L (5th-95th percentile 0.31–1.9 mg/L; specific gravity adjusted). In multivariable-adjusted regression models, every 1 mg/L increase of maternal urinary fluoride was associated with a mean increase in birth weight by 84 g (95%CI: 30, 138), length by 0.41 cm (95%CI: 0.18, 0.65), head circumference by 0.3 cm (95%CI: 0.1, 0.4), and with increased odds of being born large for gestational age (OR = 1.39, 95%CI: 1.03, 1.89). Every 1 mg/L increase of maternal urinary fluoride was also associated with a mean increase of the plasma fT3:fT4 ratio (B = 0.007, 95%CI: 0.000, 0.014), but not with the hormones or TSH. In mediation analyses, the maternal fT3:fT4 ratio did not explain the urinary fluoride-birth size relationships.
Discussion: Gestational urinary fluoride concentrations were associated with increased size at birth and even with increased odds of being born large for gestational age. The fluoride-related associations with increased size at birth were not explained by changes in maternal thyroid hormone levels.

urinary Fluoride

Gestational age at birth

Birth weight

Thyroid hormones

Birth length

Large for gestational age

Birth head circumference

Författare

Mariza Kampouri

Karolinska Institutet

Klara Gustin

Karolinska Institutet

Mia Stråvik

Chalmers, Biologi och bioteknik, Livsmedelsvetenskap

Malin Barman

Chalmers, Biologi och bioteknik, Livsmedelsvetenskap

Karolinska Institutet

Michael Levi

Karolinska Institutet

Vasiliki Daraki

Heraklion University Hospital

Bo Jacobsson

Göteborgs universitet

Sahlgrenska universitetssjukhuset

Anna Sandin

Umeå universitet

Ann-Sofie Sandberg

Chalmers, Biologi och bioteknik, Livsmedelsvetenskap

Agnes E Wold

Göteborgs universitet

Marie Vahter

Karolinska Institutet

Maria Kippler

Karolinska Institutet

Environmental Research

0013-9351 (ISSN) 1096-0953 (eISSN)

Vol. 214 114129

Ämneskategorier

Pediatrik

Miljömedicin och yrkesmedicin

Reproduktionsmedicin och gynekologi

DOI

10.1016/j.envres.2022.114129

PubMed

35998692

Mer information

Senast uppdaterat

2022-09-05