Table 1.

Serum levels of TSH and FT4 in pregnant women^a.

BMI (Kg/m2)	TSH mIU/L			FT4 pmol/L
	Median	2.5th–97.5th	P value	Median	2.5th–97.5th	P value
<18.5	1.85	0.17–5.50		16.52	12.95–22.18
18.5–24.9	1.86	0.27–6.10	0.642	16.10	12.25–21.10	<0.001b
25.0–29.9	2.11	0.37–6.78	<0.001b	15.34	11.90–19.68	<0.001b
≥30.0	2.50	0.56–13.82	0.004b	14.67	10.25–18.77	<0.001b

TSH: thyroid stimulating hormone; FT4: free thyroxine.

^aThe P value represent the median level of this group compared with the upper group.

^b P < 0.008 was considered as a significant difference.