. 2021 Aug 17;10(9):1125–1133. doi: 10.1530/EC-21-0376

Table 1.

Characteristics of the pregnant women in the study population (n = 5529).

	Median	IQR
Age (years)	29.9	26.6–33.3
BMI (kg/m²)^a	23.9	21.4–27.5
Week of blood sampling	10	9–11
Thyroid function tests
TSH (mIU/L)^b	1.18	0.724–1.80
TSH (mIU/L)^c	1.04	0.627–1.59
Free T4 (pmol/L)^b	16.6	15.3–18.0
Free T4 (pmol/L)^c	16.2	15.0–17.6
Free T4 index (nmol/L)^{b, d}	113	100–126
Total T4 (nmol/L)^b	127	112–144
Total T3 (nmol/L)^b	2.34	2.06–2.66
Free T3 (pmol/L)^b	5.05	4.70–5.47

^aCalculated from pre-pregnancy weight and height. ^bMethod A (Cobas 8000, Roche Diagnostics). ^cMethod B (ADVIA Centaur XPT, Siemens Healthineers). ^dCalculated as total T4 divided by T-uptake.

IQR, interquartile range; TSH, thyroid-stimulating hormone; T4, thyroxine; T3, triiodothyronine.