Skip to main content

Table 1 Characteristics of the study participants, i.e. 307 mother-infant pairs recruited in 1996-1999

From: Maternal body burdens of PCDD/Fs and PBDEs are associated with maternal serum levels of thyroid hormones in early pregnancy: a cross-sectional study

Characteristic N Median (Range)
Maternal age (years) 307 28 (18–41)
Maternal pre-pregnancy BMI (kg/m2) 307 23 (18–44)
Maternal weight gain during pregnancy (%)a 304 22 (3.9–46)
Gestational length (days)b 138 280 (249–300)
Birth weight of the child (g)b 150 3510 (2430–5000)
Age of infant at 3-weeks-sampling (days)b 148 24 (17–38)
Weight of the infant at 3 monthsc 109 6180 (4350–8600)
Age of infant at 3-months-sampling (days)c 115 91 (75–123)
Maternal serum TH concentrations, early pregnancy   
 TSH (mIU/L) 220 1.3 (0.002–7.5)
 Total T3 (nmol/L) 219 2.4 (0.57–3.7)
 Free T4 (pmol/L) 220 11 (7.8–20)
Maternal serum TH concentrations, late pregnancy   
 TSH (mIU/L) 281 1.4 (0.06–6.7)
 Total T3 (nmol/L) 281 2.5 (1.1–3.8)
 Free T4 (pmol/L) 281 8.3 (5.7–13)
 anti-TPOd (kIU/L) 260 8.6 (5.5–134)
Infant serum TH concentrations, 3 weeks of age   
 TSH (mIU/L) 148 2.4 (0.54–6.4)
 Total T3 (nmol/L) 145 2.8 (1.4–4.2)
 Free T4 (pmol/L) 150 17 (12–23)
Infant serum TH concentrations, 3 months of age   
 TSH (mIU/L) 115 1.8 (0.77–4.8)
 Total T3 (nmol/L) 115 3.0 (1.7–4.2)
 Free T4 (pmol/L) 114 15 (10–22)
  N %
Country of birth   
 Nordic country 291 95
 Non-Nordic country 16 5
Years of education   
 ≤4 years of high school 144 49
 1–3 years of higher education 72 24
 >3 years of higher education 79 27
Smoking habits during pregnancy (smoker/non-smoker) 58/194 19/81
Alcohol during pregnancy (no/yes) 254/52 83/17
Mode of delivery (vaginal/caesarean)b 120/18 87/13
Sex of the child (male/female)b 83/67 55/45
  1. a(weight gain during pregnancy/weight before pregnancy)*100
  2. bAmong 150 infants with analysed THs in serum at 3 weeks of age
  3. cAmong 115 infants with analysed THs in serum at 3 months
  4. dThyroid peroxidase antibodies