Abstract: | Because placental polychlorinated dibenzo-p-dioxins,dibenzofurans (PCDD/Fs) levels are associated with decreased freethyroxine (FT 4 ) and thyroid stimulating hormone (TSH) in neonates,we assessed development by gender and maternal PCDD/Fs exposureat years 2 and 5 in 92 mother and newborn pairs. RIA quantifiedthyroid, sex, and growth hormones. Of 200 subjects followed up fromNovember 2000, 136 and 149 were observed at year 2 and year 5,respectively. PCDD/Fs exposure levels were low (n 35) or high (n 35) in 70 subjects at year 2, low (n 21) or high (n 20) in 41 at year5. Height, weight, BMI, and head circumference were significantlyhigher in males, chest girth significantly higher in females at year 2.Significantly, more girls had higher bone age (BA) and chronologicalage (CA) at both times. Height, weight, FT 4 TSH, and transthyretin(TTR) at year 2; and height, triiodothyronine, and IGF-1 at year 5differed significantly by PCDD/Fs level. In females, height, weight, CA,BA, and thyroid hormones differed significantly at year 2. In males,FT 4 TSH at year 2 and IGF-1 at year 5 were significantly higher inthe high PCDD/Fs group. In utero exposure to PCDD/Fs differen-tially affects growth and hormone levels in male and female pre-school children |