Maternal body burdens of PCDD/Fs and PBDEs are associated with maternal serum levels of thyroid hormones in early pregnancy: a cross-sectional study.
BACKGROUND
Thyroid hormones (THs) regulate many biological functions in the human body and are essential for normal brain development. Epidemiological studies have observed diverging associations between halogenated persistent organic pollutant (POP) exposure and concentrations of THs in pregnant women and their infants. We investigated whether background exposure to polybrominated diphenyl ethers (PBDEs) is related to TH status in a Swedish population of pregnant women and their infants. Furthermore, we examined associations between polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) and TH status in early pregnancy as an extension of an earlier study focusing on late pregnancy TH status.


METHODS
Free thyroxine (T4), total triiodo-thyronine (T3) and thyroid stimulating hormone (TSH) were analysed in serum from first-time mothers (N = 220-281) in the first and third trimester, and in infants (N = 115-150) 3 weeks and 3 months after delivery. Antibodies to thyroid peroxidase (anti-TPO) (N = 260) were measured in maternal third trimester serum. Maternal body burdens of PCBs (N = 281) were estimated from serum lipid PCB concentrations in late pregnancy, and PCDD/F (N = 97) and PBDE (N = 186) body burdens were estimated from concentrations in mother's milk lipids 3 weeks after delivery. Linear regression models allowed for covariate adjustment of the associations between ln-transformed POP body burdens and concentrations of TH and anti-TPO.


RESULTS
Maternal body burden of BDE-153 was inversely associated with first trimester total T3, otherwise no associations between PBDEs and first and second trimester THs were observed. No associations were found between maternal PBDE body burdens and infant THs. Maternal body burden of PCDD/Fs were inversely associated with first trimester total T3. No associations were observed between PCBs and first trimester THs. Third trimester anti-TPO was not associated with maternal PCBs, PCDD/Fs and PBDEs.


CONCLUSIONS
Our results suggest that maternal PCDD/F and BDE-153 body burdens influence maternal TH status in early pregnancy, which is a critical period when maternal TH status influences fetal development.
Risk Benefit Assessment Department, National Food Agency, Box 622, SE-751 26, Uppsala, Sweden. sanna.lignell@slv.se.
Sanna
S
Lignell
Chemistry Department, National Food Agency, Box 622, SE-751 26, Uppsala, Sweden.
Marie
M
Aune
Risk Benefit Assessment Department, National Food Agency, Box 622, SE-751 26, Uppsala, Sweden.
Per Ola
PO
Darnerud
Department of Medical Sciences, Uppsala University, SE-751 85, Uppsala, Sweden.
Mats
M
Stridsberg
Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE-171 77, Stockholm, Sweden.
Annika
A
Hanberg
Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE-171 77, Stockholm, Sweden.
Susanna C
SC
Larsson
Risk Benefit Assessment Department, National Food Agency, Box 622, SE-751 26, Uppsala, Sweden.
Anders
A
Glynn
D000293:Adolescent; D000328:Adult; D001572:Benzofurans / Q000032:analysis* / Q000097:blood; D001822:Body Burden; D003430:Cross-Sectional Studies; D000072338:Dibenzofurans, Polychlorinated; D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000032:analysis* / Q000097:blood; D005260:Female; D055768:Halogenated Diphenyl Ethers / Q000032:analysis* / Q000097:blood; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D018811:Maternal Exposure; D008895:Milk, Human / Q000737:chemistry; D011078:Polychlorinated Biphenyls / Q000032:analysis* / Q000097:blood; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives* / Q000032:analysis / Q000097:blood; D011247:Pregnancy; D013548:Sweden / Q000453:epidemiology; D013963:Thyroid Hormones / Q000097:blood*; D055815:Young Adult
D001572:Benzofurans; D000072338:Dibenzofurans, Polychlorinated; D004785:Environmental Pollutants; D055768:Halogenated Diphenyl Ethers; D000072317:Polychlorinated Dibenzodioxins; D013963:Thyroid Hormones; D011078:Polychlorinated Biphenyls
Dioxins; PBDEs; PCBs; T3; T4; TSH; Thyroid hormone