Table 2.

Mean (sd), median, 20th and 80th percentiles of urinary iodine concentration (UIC), ratio of iodine to creatinine (I:Cr) and serum thyroid-stimulating hormone (TSH)^* among the study participants: pregnant women aged 19–43 years (n 162), Reykjavik, Iceland, November 2007 to February 2009

	n	Mean	sd	Median	20th	80th
UIC (μg/l)	162	228	190	180	79	340
I:Cr (μg/g)	158	231	174	173	106	319
TSH (mmol/l)	132	1·7	0·9	1·5	1·1	2·0

^*Analysis of urinary creatinine was missing for four women and thirty refused to have their blood drawn for analysis of TSH.