Reference Intervals of Thyroid Hormones and Correlation of BMI with Thyroid Function in Healthy Zhuang Ethnic Pregnant Women

Table 2

The number and percentage of results potentially misclassified if nonpregnant reference intervals are used.

		1st trimester		2nd trimester		3rd trimester
	N	Misdiagnosis	Missed	Misdiagnosis	Missed	Misdiagnosis	Missed	Overall
TSH	3254	241(30.01%)	19(2.37%)	271(14.50%)	47(2.51%)	47(8.06%)	14(2.41%)	642(19.73%)
FT4	3260	29(3.54%)	20(2.44%)	137(7.37%)	45(2.42%)	103(17.73%)	13(2.24%)	347(10.64%)
FT3	3261	2(0.24%)	20(2.45%)	14(0.75%)	45(2.42%)	104(17.87%)	14(2.41%)	199(6.10%)

N: the number of women with TSH, FT4, and FT3 levels within 95% confidence intervals or within the reference intervals provided by the assay manufacture. Misdiagnosis: the level of thyroid hormones above 2.5th confidence limit in the present study and below the lower reference interval provided by the assay manufacture; missed: the level of thyroid hormones above 97.5th confidence limit and below the higher reference interval provided by the assay manufacture or the level of thyroid hormones above the lower reference interval provided by the assay manufacture and below the 2.5th confidence limit.