Table 3.

Odds of miscarriage by serum TSH levels in the first trimester.

TSH (mIU/L)	Case (n = 418) (%)	Control (n = 1670) (%)	Unadjusted		Adjusted for confounding factorsa		Adjusted for confounding factorsb		Adjusted for FT4
			P value	OR (95% CI)	P value	OR (95% CI)	P value	OR (95% CI)	P value	OR (95% CI)c
<0.4	12 (11.5)	92 (88.5)	0.096	0.59 (0.32–1.10)	0.095	0.59 (0.32–1.10)	0.053	0.53 (0.28–1.01)	0.053	0.53 (0.28–1.01)
0.4–<2.5	239 (18.1)	1084 (81.9)		1		1		1		1
2.5–<4.87	141 (24.5)	434 (75.5)	0.001	1.47 (1.16–1.87)	0.001	1.48 (1.17–1.88)	0.001	1.51 (1.19–1.91)	0.001	1.50 (1.18–1.90)
≥4.87	26 (30.2)	60 (69.8)	0.006	1.97 (1.22–3.18)	0.005	1.99 (1.23–3.22)	0.004	2.05 (1.26–3.32)	0.004	2.02 (1.25–3.28)

^aConfounding factors include age, alcohol consumption, smoking status, BMI, history of miscarriage and high blood pressure. ^bConfounding factors include FT₄, age, alcohol consumption, smoking status, BMI, history of miscarriage and high blood pressure. ^cThe OR expresses the risk of miscarriage after controlling FT₄.