Association between Maternal Thyroxine and Risk of Fetal Congenital Heart Defects: A Hospital-Based Cohort Study

Figure 2

Maternal free thyroxine (pmol/L) and the free-to-total thyroxine proportion (%) between women whose infants had and did not have congenital heart defects by the trimesters at the thyroid function test. Abbreviations: FT4, free thyroxine and FTT4P, free-to-total thyroxine proportion. (a) The free thyroxine and (b) the free-to-total thyroxine proportion. The bottom and top edges of each box represent the first (P25) and third quartiles (P75), respectively. The band within the box represents the median (P50), and the whiskers represent values that are 1.5 times the interquartile range. values for the Mann–Whitney U test.

(a)

(b)